Support Care Cancer DOI 10.1007/s00520-015-2685-x

ORIGINAL ARTICLE

Women’s experiences of hormonal therapy for breast cancer: exploring influences on medication-taking behaviour Caitriona Cahir & Stephan U. Dombrowski & Catherine M. Kelly & M. John Kennedy & Kathleen Bennett & Linda Sharp

Received: 25 September 2014 / Accepted: 23 February 2015 # Springer-Verlag Berlin Heidelberg 2015

Abstract Purpose Five to 10 years of adjuvant hormonal therapy is recommended to prevent breast cancer recurrence. This study investigated modifiable influences on adjuvant hormonal therapy medication-taking behaviour (MTB) in women with stage I–III breast cancer. Methods Semi-structured face-to-face interviews among women with stage I–III breast cancer prescribed adjuvant hormonal therapy purposively sampled by their MTB at two cancer centres. Thematic analysis was conducted based on the Framework approach, with the Theoretical Domains Framework (TDF) informing the analysis framework; the TDF is an integrative framework consisting of 14 domains of behavioural change to inform intervention design. Results Thirty-one women participated in interviews (14 adherent/persistent; 7 non-adherent/persistent; 10 non-persistent). Three domains identified both barriers and enablers to hormonal therapy MTB across the three MTB strata: beliefs about consequences, intentions and goals and behaviour regulation, but their influence was different across the strata. C. Cahir (*) : K. Bennett Department of Pharmacology and Therapeutics, Trinity College Dublin, Dublin, Ireland e-mail: [email protected] S. U. Dombrowski Division of Psychology, University of Stirling, Stirling, Scotland C. M. Kelly Medical Oncology, Mater University Hospital, Ireland and University College Dublin, Dublin, Ireland M. J. Kennedy Medical Oncology, St James’s Hospital, Ireland and Trinity College Dublin, Dublin, Ireland L. Sharp National Cancer Registry Ireland, Cork, Ireland

Other domains influenced individual MTB strata. Key enablers for adherent/persistent women were identified within the domain beliefs about consequences (breast cancer recurrence), intentions and goals (high-priority), beliefs about capabilities (side effects) and behaviour regulation (managing medication). Barriers were identified within the domain behaviour regulation (no routine), memory, attention and decision processes (forgetting) and environmental context and resources (stressors) for non-adherent/persistent women and intentions and goals (quality of life), behaviour regulation (temporal self-regulation), reinforcement, beliefs about consequences (non-necessity) and social influences (clinical support) for non-persistent women. Conclusion This study identified modifiable influences on hormonal therapy MTB. Targeting these influences in clinical practice may improve MTB and hence survival in this population. Keywords Hormonal therapy . Medication-taking behaviour . Adherence . Breast cancer

Introduction Five to 10 years of adjuvant hormonal treatment is recommended to prevent breast cancer recurrence and mortality in women with hormone responsive early breast cancer, reducing the recurrence rate by up to 50 % [1, 2]. However, despite the proven clinical efficacy of adjuvant hormonal therapy, many women do not complete treatment as recommended. Medication-taking behaviour (MTB) can be defined in terms of two distinct patterns of behaviour, persistence which is continuing the treatment for the prescribed duration of time and adherence which is acting in accordance with the prescribed interval and dosage of the treatment [3]. Rates of non-persistence with adjuvant hormonal therapy range

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between 16 and 32 % in clinical trials and 31 and 73 % in routine clinical settings at 5 years, while prevalence of nonadherence ranges from 38 to 60 % [4, 5]. Reduced hormonal therapy exposure, due to either non-persistence or nonadherence, has been associated with an increased risk of breast cancer recurrence and mortality [6–8]. Despite the high prevalence of hormonal therapy nonadherence and non-persistence, little is known about what influences hormonal therapy MTB [4]. Quantitative studies have indicated that extremes of age (i.e. older or younger), increasing out of pocket costs, follow-up care with a general practitioner versus oncologist and treatment side effects are largely negatively associated with adherence. Taking more medications at baseline, referral to an oncologist and earlier year at diagnosis are positively associated with adherence, but the evidence is inconsistent and the reasons for these associations are not understood [4, 9]. Few studies have examined the modifiable influences on hormonal therapy MTB and whether these influences differ for non-persistence and non-adherence. The aim of this study was to use qualitative methods to investigate influences on adjuvant hormonal therapy MTB in women with stage I–III breast cancer.

Methods Design This was a qualitative study using semi-structured face-to-face interviews among women with stage I–III breast cancer prescribed adjuvant hormonal therapy and the Framework Method with the Theoretical Domains Framework (TDF) informing the analysis framework [10]. Participants Participants were purposively sampled across two cancer centres in Ireland with strata defined by their hormonal therapy MTB. Eligible participants were identified from the cancer centres’ oncology databases and were aged ≥18 years, English speaking, had stage I–III invasive breast cancer at diagnosis and had been prescribed adjuvant hormonal therapy for ≥3 months at the time of study commencement. Their MTB was evaluated using information recorded in the cancer centres’ oncology database on frequency of hormonal therapy prescriptions and relevant discussions during clinical consultations (i.e. clinical reports of hormonal therapy MTB difficulties or concerns). Eligible participants were categorised into three preliminary purposive sampling strata (adherent and persistent, non-adherent and persistent and non-persistent). Women were then sampled within these strata, and those selected were invited, by post, by their oncologists, to take part in the study. Women who indicated that they were interested in

receiving more information about the study were contacted by the researcher (CC). The researcher (CC) explained the interview process, and women were asked if they were currently taking their hormonal therapy or not (persistent/non-persistent) and if they had any difficulty remembering to take their hormonal therapy (adherent/non-adherent). The researcher (CC) then scheduled interviews with women who were willing to participate in the study. Participants were recruited into three separate MTB strata: adherent and persistent, non-adherent and persistent and nonpersistent. Adherent and persistent participants reported that they took their hormonal therapy at regular intervals and for the prescribed duration of time. Non-adherent and persistent participants did not take their hormonal therapy at regular intervals but continued to take their treatment for the prescribed duration of time. Non-persistent participants had ceased taking their hormonal therapy completely or for a period ≥3 months for non-clinical reasons or against their oncologists’ recommendations [3]. As interviews progressed, recruitment was focused on the unfilled MTB strata. In addition, attempts were made to ensure that the sample was heterogeneous in terms of age, marital status and socio-economic background. Ethical approval was obtained from the individual hospital Research Ethics Boards, and all participants provided informed consent. Participants’ oncologists (and other staff at the clinic) were not aware of, nor were they informed of, which women had agreed to participate.

Procedures An interview topic guide was developed based around the TDF (Additional file 1) [11]. The TDF was developed by Michie et al. in 2005 to provide a comprehensive assessment of behavioural determinants to inform systematic intervention design. Michie et al. mapped 128 constructs from 33 theories and identified 12 discrete domains of behaviour change and exemplar questions for each domain to be used in interviews or focus groups. The TDF has recently been validated and refined to include 14 domains with three domains further subdivided to become six domains and one domain Nature of the Behaviours removed from the framework [11–13]. In this study, the interview questions explored factors that might influence hormonal therapy MTB for each domain. All interviews were conducted face to face by the researcher (CC) and were audio recorded with the interviewee’s permission. Interviews lasted between 40 and 90 min and were transcribed verbatim and anonymised. Recruitment continued until saturation was reached in each MTB strata where further interviews did not provide any new or relevant information [14].

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Analysis Thematic analysis was conducted based on the Framework approach, with the TDF informing the analysis framework [15]. In line with the Framework approach, an overview of the entire data set was initially obtained. After familiarisation, two investigators (CC, AT) independently coded four interviews and compared and discussed results to develop a coding index which was then applied to the remainder of the interviews [10, 15]. The coding index was achieved by identifying recurrent themes introduced into the interviews through the topic guide. The index was then used to construct a set of thematic matrices or charts according to key constructs and domains from the refined TDF in the software package NVIVO 10. Each domain and its associated constructs were plotted on a separate thematic chart [10, 12, 15]. A health psychologist (SD) independently reviewed the allocation of the codes to the TDF constructs and domains. The investigators (CC, SD) held regular discussions to resolve differences in the allocation of codes and reach consensus and discussed uncertainties with the broader research team (LS, KB). The refined TDF domains and theoretical constructs were applied deductively to the data set using the Framework approach [10]. The refined TDF was also modified somewhat inductively to reflect the content of the data set [12]. The two domains intentions and goals were incorporated into one domain (intentions and goals) in line with the original framework [11]. The domain optimism was renamed personality and extended to include other personality constructs, such as resilience and conscientiousness which had emerged from the

Table 1 Participants’ characteristics by hormonal therapy medication-taking behaviour strata

Non-persistent includes three women who are considering stopping treatment

b

Employed outside of home (includes self-employed)

Results Participant characteristics Thirty-one women participated in interviews (mean age 51 years, SD±10), 14 women were adherent and persistent, 7 women were non-adherent and persistent and 10 women were non-persistent (Table 1). Three women were currently taking their treatment but planning to stop before the prescribed duration of time; this MTB emerged during the

Non-adherent and persistent N=7

Non-persistenta N=10

4 7 3

6 1 -

4 1 1 4

8 6

6 1

6 4

12 2

4 3

2 8

Adherent and persistent N=14 Age ≤40 years 41–50 years 51–60 years >60 years Area of residence Urban Rural Education Primary and/or secondary Third-level Relationship status Single

a

data set. Having revised the domains optimism and intentions and goals using an inductive approach, the literature was reviewed, and psychological theories were applied deductively to validate the modification of the TDF [10]. The TDF domains were reviewed independently (CC, SD) for each strata and graded as having “no”, “some” or a “key” influence on hormonal therapy MTB. The domains were perceived to either enable or present barriers to hormonal therapy MTB. The key, or most influential, domains for each MTB strata were identified based upon the following criteria: (i) participants expressed strong views or beliefs within the domain, which were discussed at great length or with intensity; (ii) participants frequently expressed views or beliefs within the domain; and (iii) participants from different MTB groups expressed conflicting or opposing views within the domain [16, 17]. Illustrative quotes have been provided to supplement narrative descriptions.

Married/cohabiting Employedb Yes No

2

1

4

12

6

6

5 9

4 3

7 3

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interview process, and these women were categorised as a subgroup of the non-persistent strata.

consequences, intentions and goals and behaviour regulation. Other domains were also considered to have an influence for particular strata (Table 2).

Key domains Thirteen of the possible 14 TDF domains emerged as potential influences on hormonal therapy MTB. The domain skills was not perceived to be influential as the only skill identified was to swallow a tablet, as one woman stated “You put a tablet in your mouth and swallow it, it couldn’t be much simpler” (P 5). Three key domains identified both barriers and enablers to hormonal therapy MTB across the three MTB strata, but their influence was different for each strata: beliefs about

Table 2

Adherent and persistent women—summary of domains Enablers to hormonal therapy MTB were identified in four key domains for adherent and persistent women: beliefs about consequences, intentions and goals, beliefs about capabilities and behaviour regulation. The domains emotion, personality, memory, attention and decision processes, social influences and social identity were also perceived to have some influence on hormonal therapy MTB (Table 2).

The influence of the theoretical domains on hormonal therapy medication-taking behaviour by medication-taking behaviour strata

Medication behaviour taking strata Domains

Adherent and persistent

Non-adherent and persistent

Non-persistent

Knowledge Skills Social influences Social identity Beliefs about capabilities Beliefs about consequences Reinforcement Intentions and goals Personality Emotion Behaviour regulation Memory, attention and decision processes Environmental context and resources Domain had no influence on hormonal therapy medication-taking behaviour Domain had some influence - and enabled hormonal therapy medication-taking behaviour Domain had a key influence and enabled hormonal therapy medication-taking behaviour Domain had some influence and presented barriers to hormonal therapy medication-taking behaviour Domain had a key influence and presented barriers to hormonal therapy medication-taking behaviour Domain had a key influence and presented both enablers and barriers to hormonal therapy medication

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The beliefs about consequences domain consisted of three main constructs: beliefs about treatment, outcome expectancies and anticipated regret. Adherent and persistent women strongly believed in the efficacy and necessity of their therapy, describing it as a “life rope” or “life line”. They believed that the benefits of their treatment far outweighed the side effects. They spoke about the risks of not taking their treatment and the regret they would feel should their breast cancer recur (Table 3). Adherent and persistent women expressed strong intentions to continue to take their treatment for the 5 year period to prevent breast cancer recurrence (intentions and goals). They were self-motivated and/or externally motivated by family (Table 3). Related to this was the domain emotion and women spoke about their fear of cancer recurrence motivating them to take their treatment, regardless of the side effects, and preventing them from forgetting to take it on a daily basis. Adherent and persistent women had high levels of both maintenance and coping self-efficacy and self-determination (beliefs about capabilities). They demonstrated a number of adaptive coping skills (Table 3). Women were generally optimistic and demonstrated resilience with their therapy and talked about “fighting it (side effects)” and “being a strong person” (personality). The behaviour regulation domain consisted of temporal regulation (time perspective) and constructs relating to the organisation and planning around the physical taking of hormonal therapy. Adherent and persistent women were focused on distant outcomes (breast cancer recurrence) (temporal regulation). Women exhibited, or spoke about, action and coping planning, self-monitoring and developing a routine. They developed organisation skills and strategies to effectively manage and remember to take their treatment on a daily basis, including the use of pill boxes and cues (e.g. breakfast/ dinner time) (Table 3). Related to this domain was the domain memory, attention and decision making processes for a small number of women who rather than using cues took their therapy at a set time each day. Women also reported a good relationship with their oncologist/clinical team, assumed a “patient role” by taking instruction from their oncologist/clinical team and had faith in their knowledge and expertise (social influences, social identity). Non-adherent and persistent women—summary of domains Barriers to hormonal therapy MTB were identified in three key domains for non-adherent women: behaviour regulation, memory attention and decision processes and environmental context and resources (Table 2). Within these three domains, non-adherent women reported difficulty with developing a medication taking routine, self-monitoring and refilling their prescription and environmental stressors (e.g. change in routine, travelling) (Table 4). They relied on their memory to take

their therapy and most reported memory problems. The domain knowledge had some influence, but this was not a key domain. Non-adherent women reported an understanding of what their therapy was for and what it does but felt they were given too much negative information (Table 4). Enablers to hormonal therapy persistence for non-adherent women were identified in three key domains: beliefs about capabilities, intentions and goals and beliefs about consequences, similar to those seen for adherent women (Table 2). However, barriers were also identified in the domain beliefs about consequences. Non-adherent women had negative perceptions of prescription medication generally and had to overcome these fears and concerns to take their treatment. Their strong beliefs about the necessity of their therapy and positive outcome expectancies helped them overcome their negative beliefs (Table 4). The domain emotion was related to this domain, and some women reported resentment about having to take hormonal therapy and described negative effects including bad moods, periods of crying and anxiety over their treatment. Non-persistent women—summary of domains Barriers to hormonal therapy MTB were identified in five key domains for non-persistent women: intentions and goals, behaviour regulation (temporal self-regulation), reinforcement, beliefs about consequences and social influences (Table 2). Non-persistent women described their preference for a better quality of life and to enjoy the remaining time they felt they had left to live. They wanted to be finished with their treatment (intentions and goals) were focused on current outcomes (behavioural regulation: temporal self-regulation) and felt their treatment conflicted with their everyday life and plans (goal conflict). Many women reported an improvement in their quality of life and feeling “back to myself” once they ceased taking their therapy (reinforcement) (Table 5). Non-persistent women reported a general distrust of medication and a fear of becoming dependent on medication (beliefs about consequences). These women did not perceive their therapy to be a necessity and were not prepared to tolerate the side effects. They were willing to take the risk of breast cancer recurrence and highlighted the fact that women can survive without hormonal therapy and spoke about women dying despite having taken it (social influences: norms) (Table 5). They also spoke about a lack of clinical support, including inconsistent service provision and inadequate time to address their questions or concerns (social influences). Barriers within the domains social identity and knowledge also had some influence but were not key domains. Non-persistent women spoke about a desire to take responsibility for their own health and to make conscious decisions and “not just go along with whatever is recommended” (social identity). They also spoke about a lack of understandable information

Support Care Cancer Table 3 Domain

Adherent and persistent women: enablers to hormonal therapy medication-taking behaviour by theoretical domains Construct

Beliefs about Beliefs about consequences treatment

Sub-construct

Sample quotes

General

It’s my life rope. I feel that’s what is preventing the cancer coming back. (P24) I feel my cancer that I had is over, it coming back is not over. It’s a life line, it is modern medicine giving you a life line, why would you reject a life line that’s been handed to you. (P30) This tamoxifen is here to save your life, to give you every chance in the world of staying cancer free. I just see tamoxifen as an extension of the treatment that I have to go through. I got diagnosed, I had cancer, I had surgery, I had chemotherapy, I had radiotherapy and now this is the next part of the treatment cycle. (P15) This is controlling one thing and you have to have your side effects. You have to take the good with the bad, you have to accept it. (P16) I'd rather put up with the bone pain and the cystitis and hot flushes than having to go through chemotherapy again and surgery. I just think you weigh it up. I do think definitely, the benefits outweigh the negatives on it, for me. (P14) It is a means to an end. You have something to latch on to, you say well this will keep my estrogen down so that cancer won’t come back. I wouldn’t be without it now cos it is like a cushion, you are fairly safe when you are on it, rather than not. (P1) Took the pill to stop getting pregnant taking tamoxifen to stop getting cancer. (P14) My feeling towards the pill is that this is preventing the cancer from coming back. I’m putting all my hopes in, that tiny little pill is going to keep me well for the next five years. (P9) I would be afraid if I stopped and it came back it would be like ‘why didn’t I stay on it, I’m after causing all this trouble again’. (P18) It’s my decision in the end of the day if I want to take it or if I don’t want to take it, if I refuse to take it there’s nothing my doctor can do. But on the other hand I don’t want to take the risk because if you go against the professional maybe if you get sick again they’re going to say oh hold on, we told you to do this but you didn’t and now there’s no point complaining. (P5) For 5 years I will take that tablet, because if it is the barrier between getting it and not getting it, I will take that tablet. I am adamant that I will take it for the 5 years. I will definitely take it for 5 years until they tell me to stop. (P1) I just wouldn’t stop taking it now. No, definitely not. I’m just going to have a few sweats and that. (P22) I wouldn’t go off it to save my life, excuse the pun. Definitely, there’s no way I would not take it, not in a million years, absolutely not, I wouldn’t even contemplate it. (P30) I want to take it because I want to keep the cancer away, I want to live. I’m just doing everything that I can to kind of keep it away. (P22) I just want to get this over me. It was the same with the chemo, every week me goal was to get another one behind me, and it's the same with the tablets. Because you won't find five years, sure there's nearly a year now. (P16) There are parts of me where I am dying to finish tamoxifen to see if I feel a bit normal again. But I just kept that focus that, I really don’t want this to come back especially when I've two young children, I can put up with bone pain. I want to feel for myself that I gave this hundred percent. (P14) When I was told I had breast cancer I thought ‘right, this is it, I have three children at home, I want to be around for them for a lot longer’. I don’t want the cancer to come back, I have all my faith in tamoxifen. (P24) I never considered not taking it because I wanted to do all I can do to make sure I'm the one that wins this battle, not the cancer. (P15)

Necessity versus concerns

Outcome expectancies

Anticipated regret

Intentions

Strength of intention

Goals

Temporal

Distal Proximal

Motivation

Internal (self-motivated) and external (family, friends, others)

Support Care Cancer Table 3 (continued) Domain

Construct

Sub-construct

Goal conflict

Beliefs about capabilities

Self-efficacy*

Maintenance self-efficacy

Coping self-efficacy

Adaptive coping skills

Active coping

Seeking instrumental support Seeking emotional support

Positive reinterpretation and growth Reflection and relaxation coping Spirituality- meditating or praying Acceptance

Humour

Self-determination

Behaviour Regulation

Temporal selfregulation

Sense of empowerment

Sample quotes It breaks my heart that I will never be a mother. It's a hard thing to give up your womb, to give up five years of your fertility but my way of looking at things is I'd rather be childless than leave my child motherless. (P15) No matter what comes along can’t be any worse than getting cancer, so I would still take it, unless it is life threatening, which most of the side-effects aren’t. (P1) If me arm has to get amputated I'll still be taking tamoxifen. I won't be chickening out halfway through it. I'll be the hormonalist, crankiest, sweatiest, narkiest, but I'll still be taking them. (P15) The only thing would be the sweats, but I can live with that. It doesn’t stop anything, it wouldn’t stop you from living your life. (P22) The bone pain, I feel ninety but the frame of mind I'm in is, I am still willing to put up with them side effects. (P14) It does put up weight, I swim every morning, if I don’t swim I’d try go for a walk, you have to watch what you eat as well, it would bother me, but it wouldn’t bother me enough to stop taking it. It is possible to lose the weight; it’s just harder. (P22) I ring the doctor, I ring friends, I ring other people to find out. I went back to the hospital and they told me to start taking primrose oil. I’m still on it. Now it’s more manageable. I cope better. (P5) I went to a really good (support centre). It is lovely for people who are in a time in their life, when it is like the rug has been taken from underneath you. I feel that if you go to the things that are in place to help you, then you have a better chance of coming along the road and coming out the other end and thinking yeah, I’m good now. (P11) I'm quite happy now, after the cancer. I would have been a hyper person, doing this, doing that and I could never settle but I find that I'm settling now, a bit calmer. It was never important. (P16 ) Puck yourself up, go out for a cup of coffee and if I got the table at the window and the tide was in and the winter sun coming, there is nothing as nice. That was my therapy and I made it my own. (P16) I like walking or meditating. They are things that I learned to do, which I find absolutely brilliant for centering myself. I never kind of panicked or thought why me. (P11) There's days you are exhausted with it all, these sweats, just go away. I had me hard time, can that not be it. Mentally I just (pause), say it's coming on me, just deal with it, take a cold drink of water and relax then. This is gonna happen to you but it’ll pass. You can't fight it, you just have to let it happen because it's just gonna come (P16) You kind of get used to it and you laugh it off. If you're sitting with your friends having a cup of coffee your saying I'm going, I'm going, here we go girls (laughs), I'm like a traffic light. (P16) You need to know you’ve given it your all and your shot at keeping this away and there's nothing you can do then, but at least you know you’ve done your best. (P14) I’ve often thought ‘how am I going to stick this for another four years?’ but I don’t think I’d have the will to go through it again if it came back. It’s like, having a baby, your first time you don’t know, the second time you’re terrified because you know what you’re going in there for. (P18) It's pointless coming off the tamoxifen because if it did ease the pain, would I say to myself well I don’t want to take it because it's making the pain worse, where I'm focused on the big picture of don’t wanting the cancer to come back. (P14) I don’t want to go back again so that’s why I take the medication on a regular basis and I make sure I don’t forget. If you were in my position I think you would do the same thing to survive. I hope to god I never have to go through this again. (P5)

Support Care Cancer Table 3 (continued) Domain

Construct

Sub-construct

Action planning

I fill my box up every Sunday because it begins on Sunday, then it ends on Saturday, at the other end, so every Sunday I’d sit down and I’d fill the box and then I’d check to see what’s left, ‘ah yeah, I have another week’, and I’d go to the chemist. (P22) Every morning when I get up, before I do anything else, I take my tablet out and I put it there and get my breakfast ready and then while I’m having my breakfast I take it. (P11) I leave it beside my prunes in the morning. And I take prunes every morning so I leave it up in the press beside the prunes. (P20) I always have box at home, 28 days, 15, 20 days, I have extra. I make sure I have at home one box and I have 1 or 2 in the pharmacy that I’m not stuck. (P5) I never forget, it’s very important, if I go away I put one set in my case and I will make sure I have a set in my bag. If I’m away on holidays I’ll make sure if one got lost that I won’t be without it. (P30) I've tablets everywhere, I've a drawer in my dresser, that’s the tablet drawer, in me Mother’s house, but I generally have a strip of it in my wallet all the time. If I go abroad it comes with me, everywhere I go, it's part of me, it's like packing your toothbrush, you pack your medication. (P15)

Coping planning

Self-monitoring

Developing a routine

Sample quotes

Automatic

I fill my pill box up on a Monday and I put all my tablets in and then just in case, you take it in the morning and then you say to yourself, did I take my tablets, I go back and look at today and say I did. (P5) I can’t forget to take them, sometimes I used to say ‘did I take that tablet?’, because it’d be in my head all the time to take it. Then I’d know how many tablets was in me thing and I’d know I’m after taking it, but I think it’s just in your mind, you have to take it for yourself. (P26) I haven’t missed any because I have a little box with Monday, Tuesday, Wednesday, Thursday on it and I take it every night at the same time, in around the same time every night and I’d know if I’ve missed it. (P22) You get yourself into a routine and I have a routine, I take it first thing in the morning, I have me juice and me tamoxifen and that is the start of the day. And you would nearly miss it now, if you didn’t take it. (P1) Tablets are part of your life, you won’t forget. It’s part of your routine, whatever I do, wherever I go, the first thing you get up in the morning, in your head, you get in the routine that it’s very hard to forget. (P5) I go out to the kitchen every night before I go to bed and take it with a drop of water. It’s the last thing I do, more or less, brush the teeth and everything else. I value it, I actually do value it. I think when something is important enough to you, you do it, like brushing your teeth at night. (P30)

Quote identified by participant ID number

provided by health professionals, particularly in relation to side effects and having to source information for themselves (knowledge) (Table 5). Barriers were identified in one key domain, intentions and goals, for the subgroup of women who were considering stopping their hormonal therapy, similar to non-persistent women. They also spoke about a lack of clinical support and information and their desire to manage their own health (social influences, social identity). Enablers to their current persistence were identified in one key domain: beliefs about consequences. They believed in the benefits of hormonal therapy, but this was conditional on the therapy not having an adverse impact on their quality of life.

Discussion This study used qualitative methods to explore influences on adjuvant hormonal therapy MTB in women with stage I–III breast cancer. No such studies have been undertaken to date. Three domains, beliefs about consequences, intentions and goals and behaviour regulation, were identified as key domains for the different MTB strata, although their influence was different across the three strata. These three domains are discussed below, as well as their relationship with other influential domains for the individual MTB strata.

Support Care Cancer Table 4

Non-adherent and persistent women: barriers and enablers to hormonal therapy medication-taking behaviour by theoretical domains

Domain

Construct

Behaviour regulation

Self-monitoring

Developing a routine

Memory attention and decision processes

Remembering to take hormonal therapy

Environmental context and resources

Environmental stressors

Knowledge

Quantity and quality of knowledge

Sub-construct

Sample quote Yesterday the script ran out and they sent me five from the chemist ‘til I get the prescription from the doctor. They would feel that I should know when my prescription is due. I like to see as little of doctors as possible and I nearly have to pluck up the courage to ring the GP to say, oh I need the prescription. I hate it, it's another little thing you’ve to think of and remember and do. (P7) I’m probably not the most organised person and I don’t know why, I know it’s coming up to it because the pack is going down, and my husband goes mad because he’d say that’s so important and you’re just leaving it like that and then I’d get to the last one and I’d realise it’s Saturday and they’re not open on Sunday. (P17) The odd time I mightn’t remember I took it that morning and I might take it again but now I’d say to myself if I can’t remember, a day won’t matter so I will take it tomorrow. (P10) I was taking the Tamoxifen in the morning, or if I didn’t take it in the morning I would remember it by twelve o’clock, if I forgot it at least I’d remember it by dinner time. Then I was forgetting to take them. I did use my alarm and then you’d turn it off and say I’m taking it now, and you still wouldn’t go to take it, like if you were doing other things. (P17) In general it’s breakfast time and I'm on my way out to school or at the very latest I would take it is 8 pm. I will not take it after 8 pm because I have to take it early again the following day. I’d be terrified to take the two together so I just leave it. (P3) I usually take it, after breakfast, in the mornings if I remember but if not any time during the day. If I was at home, I would definitely go and take it when I remember or if I was outside or out in work, I would make a mental note to take it, when I got home. At the start, I would keep forgetting, it happened maybe a few times a week, but now I’ve got better. I never took medications really, unless the usual thing, like the flu, antibiotics. This is the longest I’ve been on medication. (P10) It was so foreign to me to have to take a tablet and to be regimented to take a tablet and all that goes with it. Cognitively I'm not as good or as sharp as I was before I got sick. And I find it's very easy for me to drop the ball and it would be very easy to get that little bit confused. (P7) Sometimes I forget, did I take it today. Sometimes I forget to get my prescriptions from the pharmacy. I have a very bad memory. (P4) There are times I’d forget, if my head is very busy. There is no way I would purposely not take it. I count along the package you see. I’d write on the box even but I still don’t because, my memory is not as it used to be. (P3) On Sunday because I'm going to church for communion and I don’t have my breakfast or coffee I forget. And I come back after church and I forget. (P4) If you had visitors or if your routine changed or if there was something going on, I might turn round and oh God I didn’t take any of my tablets. (P7) If there’s something big on or I have to bring the young one to university and then by three o’clock I could remember to take it or I might not remember to take it. But I’ll have to leave it to the following day. It would go out of my head to take it. (P3) I tend to put my head in the sand if there's any heavy duty so that’s why I've never had the conversation this is your percentage of survival, if you take it, if you don’t take it. Sometimes I don’t want to ask something that I mightn’t like the answer to. Because then you’ve to go home with that. So that’s why I limit what I want to know. (P7) I suppose it’s mad that I’ve put my trust in a doctor and a drug that I probably should know more about but the problem is I would have worried myself sick if I knew all of the bad things. (P17) I don’t want to know side effects of things. I was bombarded with a little bit too much stuff I didn’t want to know. They’re telling you, you have to know these things but I don’t. The dangers and the side effects and all that. You might think that’s a little bit naive or stupid of me, but that’s how my head works and that stops me from cracking. The basics, I just wanted the very basics. (P3)

Support Care Cancer Table 4 (continued) Domain

Construct

Sub-construct

Beliefs about consequences

Beliefs about treatment

General

Beliefs about treatment

Outcome expectancies

Sample quote

I did not take a tablet before I got cancer. If I had a flu somebody would arrive home with an antibiotic, I didn’t take it. I found it very tough to go on a tablet regime but something in my instinct just told me you need to take this tamoxifen. I knew people that would have had addictions to prescription tablets. I just found the whole thing of taking tablets, even today if I could just throw that bag out the window and say, no I don’t have to take them anymore. (P7) While I’m on this Tamoxifen, it’s always a worry, it’s always at the back of my mind, I suppose it’s like any drug. I had heard negative things about it, they said it causes ovarian cancer and things like that. (P17) It was a big deal that I had to take this tablet. When I first took it I’d have palpitations after taking it and I would be sitting waiting for it to do something else and after two hours was up, it’s grand, I didn’t die that time, I didn’t take a heart attack. I still hate taking them, but it’s not doing that anymore now. I’m aware that I have to take it. I know my body needs the tablet. (P3) Necessity versus I understand what it does. The benefits of tamoxifen are that I’m alive, concerns despite all the side effects. I suppose if I didn’t have such a strong view that it’s keeping me alive then it might be different. (P7) I’m aware of its pros and cons. But its pros far outweigh the cons. I’m aware of the dangers also of taking it and of not taking it. I’m worried about what if it gives me stomach cancer. What if I get clots, what if it starts messing round with the heart? I did think that I would end up in hospital with side effects. But I don’t like to get too far into it because I would come to a complete standstill and stop. In my head I’m safe when I take it. (P3) The benefits of taking it would outweigh the problems, the anxiety and the joint pains and stuff like that because I can manage those. If it means that I’m having a better chance of not getting breast cancer in me other breast. I’m happy that it is keeping me safe, even if it is not keeping me comfortable. (P8) People say oh you're so positive, of course I was positive because the alternative is having a chat with the undertaker. And I suppose on the tamoxifen I feel I'm avoiding that. I think l if I was off the tamoxifen I could be cognitively quicker, I could lose the weight and I would be probably amazed at how better I'd be if I was two or three stone lighter but I would be afraid to take that risk. (P7). I have myself programmed, you’re safe, each one you take that’s giving yourself complete protection against this. You’re living because of this tablet. I would be devastated if I found out after a few years that it didn’t actually benefit me at all. (P3) At this stage I don’t think anything would really happen if I stopped, but at the same time it is not a risk I want to take. (P8)

Quote identified by participant ID number

Beliefs about consequences In this study, adherent and persistent women strongly believed in the efficacy of their treatment. In contrast, non-adherent and non-persistent women had negative perceptions of hormonal therapy and a general distrust of prescription medication. However, both adherent and non-adherent persistent women believed in the necessity of their hormonal therapy, while nonpersistent women did not. Non-persistent women, unlike persistent women, did not perceive the consequences of not taking their treatment to be severe. The Health Beliefs Model has previously been applied as a framework to explain MTB, with beliefs about disease

severity, personal susceptibility to recurrence, efficacy of treatment, self-efficacy, barriers to treatment and cues to action suggested as significant influences on health behaviours [18, 19]. Specifically, greater perceived disease severity is associated with better adherence [19, 20]. In addition to illness beliefs, patients may also conduct a cost-benefit analysis by weighing up the necessity of their prescribed medication against concerns regarding potential adverse effects [21]. Previous quantitative research has shown that women with neutral or negative decisional balance scores about the value of their hormonal therapy were more likely not to persist with treatment than women with positive decisional balance scores [21–23]. This study indicates that non-persistence with

Support Care Cancer Table 5

Non-persistent women: barriers to hormonal therapy medication-taking behaviour by theoretical domains

Domain

Construct

Sub-construct

Sample quote

Beliefs about consequences

Beliefs about treatment

General

Beliefs about treatment

Necessity versus concerns

I would prefer not to take medication. I don’t trust it really, side effects and damage. I think there is a financial thing in it. Some people are doing research into medication. Not necessarily into people and medication. And when I hear about people taking medication for something and then they have to take medication to balance the medication. And before they know they’re on several things. There’s this idea that it’s better to keep on the medication and we’re holding people in this world by just feeding them medication. That would be quite an issue for me. (P2) I’m very anti-drug, just part of who I am so it took a little bit of persuading for me to go on Femara. I don’t like drugs. I don’t no, well every drug you take there’s a side effect. (P27) My main reasons for not taking it were the side effects that you read about, you’re straight in to a medically induced menopause. The mood swings, depression and I would be afraid that you would get hooked on medication, there’s so many people out there being overly medicated. (P23) There’s no nice way of telling somebody, they are the side effects, but when someone says it to you, risk of clotting, effects your bone density, all that kind of stuff, you just think ‘well I don’t think I’ll be bothered with that really’. (P19) I wasn’t prepared to feel the way I felt, I felt so horrible I said to my husband these tablets are making me feel so ill I think I'd rather take the risk with cancer than feel miserable, unhappy, fat. (P29) If the results came back from the oncotype test to say that I had a high risk aggressive cancer I would have been on it straight away. Also I don't have the genetic cancer gene. That’s how I weighed it up, those two things. I said right they’re not getting any medication in to me. It was up to me then how I was going to handle it rather than it handling me, and that’s the way I looked at it. (P23) There’s people alive taking hormone medication and there’s people still alive that haven’t taken it. You’re taking a risk with your life too taking it, and sometimes you think ‘well I’d be better off not taking it and I’d live ten years without all that crap’. (P19) I think it was a bit sharp telling me that I would die from it. The fact that if I do get the cancer back that I would die from it. But you know, I, people can live with it too. (P2) Since I’ve had mine, I wouldn’t be afraid of cancer. You hear of people dying but it is the people that are living and that are enjoying life are the ones you want to highlight as well. (P13) I feel I would have been on Tamoxifen for five years, old before my time. I would be drugged up to the eyeballs from now until…forever. (P23) What I really thought was I don’t think I want this. That’s what I was thinking. I think mainly it’s that I wanted to be finished with the treatment, I’d had the operation, I’d had the chemo, I had the radiotherapy but I just wanted to finish with it. As far as I was concerned that was the end of it. I didn’t want to be still caught into the system. (P2) I didn’t want this awful quality of life, I wanted to be me and if it meant shortening my life, I was willing to take that chance I wanted a better quality of life, than what the tablet was offering me. I’m confident, I didn’t even have to think about it, I made up my mind, this is what I wanted to do I know I will be fine. (P13) I don’t want to live in this place where I feel that the medical model has me by the scruff of the neck. I think when you’re diagnosed with cancer, you do become a victim for a while because you are in the clutches of the medical model and that’s where you need to be. But there comes a time when you’re done with your surgery and your radium and then its starts to be the treatment going forward, where you have to take back your choices for quality of life. I went for the best quality I could really for whatever will be remaining for me hopefully. The best commodity I have here now is time so how am I going to use it? (P27)

Outcome expectancies

Intentions and goals

Goals

Support Care Cancer Table 5 (continued) Domain

Construct

Goal conflict

Reinforcement

Behaviour regulation Temporal self-regulation

Social Influences

Social norms

Sub-construct

Sample quote You go in with your mind made up you don’t want to take it, and why you don’t want to take it, because I want to stay as healthy as I can for as long as I can. It’s not for me. I don’t even want to try it for three months and come off it, because it would be in my system then, it’s going to start closing everything down. (P23) If I have to take something I wanted something that doesn’t interfere with my level of functioning as much as possible. I said feck it, you want the best quality of life and you want to be able to live your life as normal as possible. (P19) I wasn’t going out much and I said to myself, if this is the way that it’s going to affect me, then I’ve no quality of life and I had plans for myself, I’m going on holiday now next week. And these were the plans that I wanted to do. (P13) I feel Tamoxifen wouldn’t have suited my lifestyle to try and do what I have to do every day. It’s fairly hard, when you’re on a time schedule with a job and you have your targets to reach in the day at a certain time. I just wanted a quality of life for myself, even if I was only to get the last year the way I’ve got it, being medication free, for me personally it would have been a better quality than having to take it. (P23) I found that I was quite down, and I do have periods where I get quite down. But when I came off it within a couple of months I realised that my mood had picked up, I could feel a kind of, a cloud lift off me. After a month or 2 off it I was suddenly full of energy. (P12) I stopped taking it three weeks ago and I feel wonderful. I started feeling better after about a week and every week that’s gone past I'm feeling better and better, I feel like me again. I feel great. (P29) Coming off the tablet has given me back that quality of life. Once I came off the tablet, I felt so well; I felt I was coming back to myself. I really feel well and I have energy. I’ve always had energy, plenty of energy, so I feel I’m back now and I’m happy in myself, because I can do things. (P13) I know I should be taking them but there's no point because I'm not enjoying life on them. I might as well be dead I thought as feeling like this. Physically, mentally, just totally. I feel great and I'm very happy with my decision because I can't see the point in prolonging life if you're miserable and you have no quality of life, and that’s how I felt on the tablets. I'm getting back to what I used to, what I was like before they put me on the tablets and I feel so much better. (P29) I chose a lesser time left. I said at my age, does it matter if the cancer comes back one way or another but if I have these few years of, I don’t go gallivanting or that, I like my home and I like being involved in the community, going to the club and that. Coming off the tablet has given me back that quality of life. (P13) I’m very realistic, I was nearly sixty one, I had a good life, I have to die of something. I think it’s more to have a life, people don’t say well will this affect my quality of life the medical model wants you to live. They want you to be the success, they want you to be the one they saved, that you’re alive but alive how? (P27) A cousin of mine was taking hormone therapy for breast cancer and ten years later the cancer came back in the other breast. So what did she achieve? Nothing. I know women eight, ten years down the line that are not taking it and they’re fine. (P19) My friend died of breast cancer. She’d a similar surgery as my own, the chemo, the radiotherapy and all that. She gave up the medication and went alternative instead. She got 6 or 7 years so if I get to 70 that’s alright you know. That’s the way I feel about it, who knows after that. (P2) I did hear through different groups, through listening to other people’s stories, that most of the people that had taken it below fifties didn’t have a very high success rate with it. One was terminally ill, my own sister she was dead at 39 and another lady's daughter died around 41 and all three were on Tamoxifen, so that made up my mind. (P23)

Support Care Cancer Table 5 (continued) Domain

Construct

Sub-construct

Clinical support

Social Identity

Patient role

Knowledge

Quantity and quality of knowledge

Sample quote Those out patients appointments, you see a different doctor all the time and they spend more time, looking through my file trying to read up what's happened to me. They’re so busy you barely get time to talk to them at all about how you’re feeling. You get your treatment and then you toddle off on your merry way and you’re left to deal with the rest of it on your own. (P12) Each time I was coming back to the clinic I was seeing registrars. I didn’t feel I was getting through with my questions. Some didn’t know the kind of cancer that I had. There should be something personal . To recognise the person who’s sitting in front of you as opposed to the, the breast cancer. Treating the cancer rather than the person, with the cancer. Which is very, that’s science isn’t it, the objectification. (P2) I just feel the medical profession certainly doing their job will prescribe, prescribe, prescribe, I’m not sure they want to listen to somebody that doesn’t want to go down the route of what they prescribe. (P23) It feels good in a way to make your own decisions about your health. I kind of feel, empowered is too strong a word, but I made the decision, I’m not just going along with whatever I’m told to do or whatever is recommended. (P12) You can accept that the medics know a certain amount, they don’t know everything. I think to stay on it doesn’t seem like a person’s responsibility. It seems like its part of the medical system. Whereas if you make a decision you’re standing outside that. I do think a lot of people aren’t making a conscious decision. They don’t know that they can decide. They are going through a process, the doctor said I take this because I have this. (P2) You need to be your own champion and ask the hard questions. I use this loosely and flippantly it’s kind of going into battle, battle for yourself. I knew that they wanted me to stay on it, they’d be trying to placate me to stay on it. I was going to tolerate that or was I going to listen to my own body. You’re your own best expert. (P27) People (clinicians) aren’t very forthcoming about telling you that information, you have to, you gather all the information as you go along yourself. But I’d be very fussy anyway, I’d want to know the in’s and out’s of everything. (P19) They could have gone through some basic information about the effects of it and what might happen if I didn’t take it. I like information. I gather information, it clarifies things for me. I don’t like to be in a bit of a morass. Because then you say, who actually knows anything here? And you do expect the professionals to know. At least to give you that bit of information and then you can at least make your decision around something that’s been clarified. (P2) Nobody tells you well if you do go on it there’s risks here that this could happen to you, you do read a little bit about that but their minimised. I think that’s to tilt it in favour of going on it. We don’t hear enough about the side effects not enough that people talk about it. Because people feel very grateful to be a survivor so it’s that whole thing nobody tells you how pregnancy and delivery is until you’re in it, it’s that whole conspiracy of silence. (P27)

NP non-persistent Quote identified by participant ID number

hormonal therapy may be due to a lack of belief in its necessity (personal need for therapy) and concerns over adverse effects, while non-adherence but persistence with treatment may be influenced by a perceived need for treatment and its associated increased life expectancy but a lack of belief, or less strong conviction, in the efficacy of the treatment.

It is also of interest that adherent and persistent women had a fear of breast cancer recurrence (within the domain emotion), but this was not the case for non-adherent and non-persistent women. Fear of breast cancer recurrence has been cited elsewhere by women as a reason for adherence to treatment [24, 25]. Higher beliefs in the necessity of taking hormonal therapy

Support Care Cancer

have also been shown to be associated with a greater fear of breast cancer recurrence [26]. Our findings suggest that nonadherent women may not perceive their hormonal therapy to be quite as important as do adherent women and are more likely to forget to take it. Intentions and goals Persistent women had strong intentions to continue to take their hormonal therapy to achieve their goal of preventing breast cancer recurrence. Non-persistent women and women considering stopping treatment valued a better quality of life over increased life expectancy. In the common sense model of self-regulation patients’ behaviour (taking or not taking hormonal therapy) represents a “common sense” response to their cognitive and emotional interpretation of their illness (breast cancer) and symptom experiences and expectations [27]. Medication beliefs have been shown to influence patients’ actual experience of treatment side effects and coping behaviours via negative expectancies [28]. Within this model, nonpersistent women’s negative perceptions of hormonal therapy may have led to an expectation of treatment side effects or a search for confirmatory symptoms and physicians offering reassurance through further drug treatments for side effects may diminish motivation to start or continue with treatment even further [28, 29]. In the domains social influences and social identity, nonpersistent women and women considering stopping treatment perceived there to be a lack of continuity of care and inadequate personal attention; they wanted greater involvement in treatment decisions, unlike persistent women who adopted a more passive approach to their health care. In other settings, greater patient-clinician collaboration and mutual agreement about goals has been associated with higher levels of adherence, greater patient satisfaction with care and better health outcomes including quality of life [30–33]. Behaviour regulation Adherent and persistent women integrated their hormonal therapy taking into their everyday life (e.g. mealtimes, bedtime). Once the routine was established, taking hormonal therapy became habitual. Non-adherent women did not develop a routine and had difficulties remembering to take their therapy. The use of implementation intentions, whereby a specific adherence behaviour is linked to an environmental cue (e.g. teeth brushing), has been shown to increase the likelihood of the behaviour being performed in a range of health behaviours such as preventative screening and lifestyle changes [34]. Our findings suggest that this may hold for medication adherence too. Temporal regulation or time perspective has been shown to explain the motivations underlying MTB by distinguishing

between individuals with an orientation toward the present or future [35, 36]. Non-persistent women demonstrated a dominant present outlook, and their priority was to avoid any discomfort, side effects or undesired lifestyle changes. In contrast, persistent women demonstrated a future orientated time perspective and were focused on the avoidance of breast cancer recurrence and used a wide range of coping strategies to manage the negative effects (beliefs about capabilities) [37, 38]. Non-adherence has previously been associated with a lack of knowledge about treatment [39]. In the current study, somewhat different findings emerged: non-adherent women wished for less information, while non-persistent women wished for more information about their hormonal therapy. The modifiable influences on hormonal therapy MTB may be different for women who are fully informed about treatment versus those who are not. Non-persistent women wanted more balanced information on the benefits and side effects of treatment. More discussion of the pros than the cons of treatment by health care providers has been reported by patients in other settings [40, 41]. Further research is needed to establish the available evidence that health care professionals actually have about the relative risk reductions in breast cancer recurrence versus experiencing unpleasant side effects and how to communicate this effectively to patients. Non-adherent women felt threatened by the volume of negative treatment information, and a lack of understanding may be associated with concerns or misconceptions about their hormonal therapy [42]. However, rather than passive information provision per se, frequent health professional communication that takes patients views into account and shapes what patients believe about their treatment and checks for understanding may improve hormonal therapy MTB [43, 44]. Strengths and limitations This study has a number of limitations given its qualitative approach and subsequent generalisability of themes. Although women were recruited from two cancer centres, there is no reason to believe that their views would be different from women treated in other cancer centres. There was a diversity of opinions expressed, and participants were diverse in sociodemographic characteristics as well as their MTB; so, it is likely that the generalisability of themes is high. There is a critical lack of understanding as to why women take or do not take their hormonal therapy. Few studies have examined modifiable influences and those that have investigated a single factor or influence [4]. In contrast, we used the TDF to identify a wide range of potential influences, and study was not confined to a particular psychological theory or groups of determinants. Moreover, the domains that were identified as being most influential were determined by two independent

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reviewers and based on a methodology adopted in previous TDF studies [16, 17]. This is the first study to apply the TDF to hormonal therapy MTB, and we plan to validate our findings further in a national quantitative population study as well as establish the inter-relationships between the various domains. The qualitative and quantitative results will subsequently inform the development of a complex intervention aimed at maximising MTB in women prescribed hormonal therapy for early stage breast cancer. A number of effective behaviour change techniques for behavioural interventions have been identified to target particular theoretical domains, and these will form the basis for future evidence-based interventions [45]. Implications We identified a range of potentially modifiable influences on women’s hormonal therapy MTB. These influences differ between women who choose to take their hormonal therapy, women who forget and women who choose not to take their hormonal therapy. Adherent and persistent women strongly believed in the necessity and efficacy of their treatment, were highly motivated and adapted a wide range of coping techniques and support networks to enable them to take their treatment. Non-adherence was associated with inadequate medication management techniques, a general distrust in medication, concerns and anxiety over treatment side effects and lack of knowledge and conviction in the efficacy of the treatment. Non-persistence was associated with a strong distrust of medication and the health care system, a lack of perceived need for treatment and a preference for a good quality of life with little concern or thought given to future outcomes. Identifying and targeting these modifiable influences in clinical practice may ultimately improve hormonal therapy MTB and thereby survival in this population. Acknowledgments We wish to thank all of the women at the two cancer centres who kindly gave their time to participate in this study. We wish to acknowledge Aileen Timmons who helped develop the coding index for this study. Funding CC is Health Research Board, Ireland (HRB) ICE fellow (ICE/2011/9) and this grant funded data collection. Conflict of interests All authors have nothing to declare. Contributors CC, KB, MJK, CMK and LS planned and designed the study. CC and AT developed the coding index. CC and SD analysed and interpreted the study data. CC drafted the manuscript. CC, SD, CMK, MJK, KB and LS critically reviewed and approved the final manuscript. CC is guarantor. Ethical approval Ethical approval was obtained from the individual hospital Research Ethics Boards and all participants provided informed consent.

Independence of researchers All authors and their affiliated institutions are independent of the Health Research Board. Access to the data All authors had full access to all of the data in the study and can take responsibility for the integrity of the data and the accuracy of the data analysis.

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