Int Urogynecol J (2012) 23:229–233 DOI 10.1007/s00192-011-1529-6

ORIGINAL ARTICLE

Validation of Persian version of the Prolapse Quality-of-Life questionnaire (P-QOL) Marzieh Nojomi & G. Alessandro Digesu & Vik Khullar & Negar Morovatdar & Ladan Haghighi & Mansoureh Alirezaei & Steven Swift

Received: 2 February 2011 / Accepted: 21 July 2011 / Published online: 17 August 2011 # The International Urogynecological Association 2011

Abstract Introduction and hypothesis The aim of this study was to evaluate the validity and reliability of a Persian translation of the Prolapse Quality-of-Life (P-QOL) questionnaire in women with pelvic organ prolapse (POP). Methods One hundred and twenty-four women with POP symptoms and 125 asymptomatic women were studied. The asymptomatic group was used for discriminant validity. Results Seventy-two percent (89/124) of the symptomatic women had stage ≥2 POP while 86% (108/125) of the asymptomatic women had a stage <2 POP. All domains of the Persian P-QOL have a Cronbach’s alpha coefficient greater than 0.7 (0.78–0.97) and were significantly different between symptomatic and asymptomatic women indicating a good discriminant validity (<0.01). The test–retest reliability confirmed a highly significant correlation. All items of P-QOL questionnaire correlated significantly with M. Nojomi (*) : N. Morovatdar Department of Community Medicine, School of Medicine, Tehran University of Medical Sciences, Crossroads of Hemmat and Chamran Expressways, 15875-6171 Tehran, Iran e-mail: [email protected] G. A. Digesu : V. Khullar St Mary’s Hospital London, Imperial College School of Medicine, London, UK L. Haghighi : M. Alirezaei Department of Obstetrics and Gynecology, Akbar-Abadi Hospital, Tehran University of Medical Sciences, Tehran, Iran S. Swift Medical University of South Carolina, Charleston, SC, USA

the objective vaginal examination findings (construct validity) except for personal relationship and emotions. Conclusion The Persian version of the P-QOL is a valid and reliable tool to assess QOL of women with POP. Keywords Quality of life . Reliability . Validity . Urogenital prolapse . P-QOL

Introduction Pelvic organ prolapse (POP) is a common, distressing, and disabling condition that results in limitations in social, physical, mental, and occupational aspects of a woman’s life [1]. The reported lifetime prevalence of POP is 30–50% [1]. It has been shown that more than 30% of women aged 50 years and older suffer from this condition which is also one of the most common causes of hysterectomy in menopausal women [2, 3]. Women with POP most often have complaints of a “feeling bulge in the vagina” or feeling pressure in the pelvis that is worse at the end of the day. However, women often seek medical care for a broad range of other complaints including urinary, bowel, and sexual symptoms [4–6]. It has been previously demonstrated that the evaluation of quality of life, which should be part of any assessment, management, and follow-up of women with urogenital prolapse, requires the use of a valid and reliable questionnaire in a patient’s own language. This questionnaire should be able to measure objectively and subjectively women’s complaints as well as their impact on quality of life (QOL). The Prolapse Quality-of-Life (P-QOL) questionnaire has been validated in English-speaking patients and translated in several languages including Thai, Portuguese, German, Japanese, Turkish, Italian, and Dutch [1, 7–14]. Therefore,

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the aim of this study was to validate the Persian version of the P-QOL questionnaire.

Methods Translation and questionnaire The P-QOL is a disease-specific instrument to measure the health-related quality of life in women with prolapse. It has 20 items representing nine quality-of-life domains which include general health, prolapse impact, role, physical and social limitations, personal relationships, emotional problems, sleep/energy disturbances, and severity measures. After having received official permission from the original authors of P-QOL, the questionnaire was translated in Persian by a native Iranian health professional translator fluent in both English and Persian. Subsequently, the questionnaire was back translated in English. Two versions of the questionnaire were compared by the investigators, and any differences were discussed and resolved. Finally, 20 women with symptomatic POP were asked to selfcomplete the questionnaire in outpatient clinics to assess patients’ understanding of items. All questions were clear, and only minor changes were needed; thus, the final version was developed. These women were not included in the final validation of the questionnaire. The responses in the P-QOL questionnaire ranged from “none/not at all” to “slightly/a little” to “moderately” to “a lot.” A 4-point scoring system for each item and a total score for each domain with score ranging between 0 and 100 were used for severity measurement of prolapse symptoms. A higher score indicated a greater deterioration of quality of life [1]. Participants and study design Between June and December 2010, consecutive women were recruited from the gynecology outpatient clinic at Akbar-Abadi Hospital (the largest maternity hospital in the capital city of Tehran, Iran) and Firoozgar Teaching Hospital. These hospitals covered >80% of all deliveries in the south and southwest of Tehran. The exclusion criteria included age less than 18 years, pregnant women, recent surgery or delivery, women with acute symptoms of urinary tract infection, women unable to read, and/or those who did not consent to participate in the study. The POP questionnaire was filled out prior to their consultation while waiting for their visit. A cover letter explaining the objectives of the study was provided to the women. Women who agreed to participate in the study were consented and, based on symptoms, were categorized into two groups: those who had symptoms of POP (feeling pressure in the vagina,

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something coming down, and sensation of vaginal bulge) were defined as symptomatic (124) whereas women without these symptoms were categorized as asymptomatic (125). All women were examined in the lithotomy position using the Pelvic Organ Prolapse Quantification (POP-Q) [15]. All terms and definitions are in accordance with the latest terminology for female pelvic floor dysfunction [16]. A local ethical approval was obtained for the study (reference number of 896/1 on February 2010). Statistical analyses The reliability of the questionnaire was assessed by its internal consistency using Cronbach’s alpha and stability using a 2-week test–retests analysis. Internal consistency refers to the degree of correlation between the items. Therefore, it is expected that items forming a domain should moderately correlate with each other, but should contribute independently to the overall domain score. A perfect correlation of 1.0 indicates that the questions are measuring an identical construct. A poor correlation, instead, suggests that the items are testing different traits. A Cronbach alpha of >0.7 has been recommended as acceptable [17]. A second P-QOL, with an accompanying letter and a pre-paid envelope, was posted and completed by the women 2 weeks later. The responses of the two completed questionnaires were then analyzed using the Cronbach alpha test [1]. A short interval between responses was chosen to ensure that women’s symptoms were unchanged. We also used Spearman’s correlation coefficient to assess the correlation between POP-Q stages and P-QOL scores of domains. The discriminant validity was evaluated by comparing the quality-of-life domain scores between symptomatic and asymptomatic patients. The P-QOL scores between symptomatic and asymptomatic women were compared using Mann–Whitney U test. T test was used to compare age, body mass index, and parity across symptomatic and asymptomatic women. Level of education, method of delivery, and POP-Q stages between symptomatic and asymptomatic women were assessed by chi-square test. We also used receiver operator characteristic curve (ROC) for assessing validity (sensitivity and specificity) of all domain scores of P-QOL between symptomatic and asymptomatic women. A data analysis was performed by SPSS version 15.0 (SPSS Inc., Chicago, IL, USA). Significance was set at 0.05 for all analyses.

Results Two hundred sixty-two women were recruited. Two hundred forty-nine women (95%) who fully completed the

Int Urogynecol J (2012) 23:229–233 Table 1 Demographic and clinical characteristics for symptomatic and asymptomatic women

231 Variable

Symptomatic (n=124)

Age (mean, years) Educational status (n, %) Less than high school High school graduate University Type of delivery (n, %) Caesarian sections Vaginal only Caesarian and vaginal None BMI (mean ± SD) Parity (mean ± SD) POP-Q findings (n, %) Stage 0 Stage 1 Stage 2 Stage 3 Stage 4

questionnaire were included in the study. One hundred twenty-four women reported POP symptoms whereas 125 did not. Mean age was 40.3 years (range 19–80). Demographic characteristics are shown in Table 1. To assess the test–retest reliability, 42 (33.8%) symptomatic women were asked to complete a second questionnaire 2 weeks later. Only 30 subjects (71.4%) returned and completed the second questionnaire. The internal consistency is shown in Table 2. All items had a coefficient of greater than 0.7, showing a satisfactory internal consistency. There was a strong correlation between vaginal examination findings and the scores of P-QOL (construct validity) as shown in Table 3. This analysis confirmed that all items of the questionnaire correlated significantly with the objective

Asymptomatic (n=125)

44.9

35.7

21 (16.9) 93 (75) 10 (8.1)

4 (3.2) 71 (56.8) 50 (40)

5 (4) 90 (72.6) 27 (21.6) 2 (1.6) 30.19±4.26 3.48±1.50

35 (28) 55 (44) 19 (15.2) 16 (12.8) 27.26±4.17 1.85±1.42

0 (0) 35 (28.2)

49 (39.2) 59 (47.2)

67 (54) 20 (16.1) 2 (1.6)

17 (13.6) 0 (0) 0 (0)

vaginal examination findings except for personal relationship and emotions. The discriminant validity is shown in Table 4. The domain scores for P-QOL of asymptomatic women were lower than those of symptomatic women showing a worse QOL in the symptomatic group. All domain scores showed significant difference between symptomatic and asymptomatic women (P<0.01). The test–retest reliability confirmed a highly significant correlation between the total scores for each domain of the baseline and second questionnaires (Table 4). Figure 1 illustrates the receiver operator characteristic curve of all P-QOL domain scores between symptomatic and asymptomatic women. All lines were above reference line with the area under curve of significance at 0.01 level.

Table 2 Internal consistency of P-QOL domain scores by Cronbach’s alpha statistic

Table 3 Correlation between POP-Q domain scores and vaginal examination findings by Spearman’s correlation coefficient (SCC) for symptomatic women

Prolapse quality-of-life domains

Prolapse quality-of-life domain scores

SCC

P value

General health perceptions Prolapse impact Role limitation Physical limitation Social limitation Personal relationship Emotions Sleep/Energy Severity measures

0.45 0.48 0.37 0.29 0.18 0.04 0.05 0.32 0.48

0.000 0.000 0.000 0.001 0.046 >0.05 >0.05 0.000 0.000

General health perception Prolapse impact Role limitation Social limitation Physical limitation Personal relationship Emotions Sleep/Energy Severity measures

Cronbach’s alpha – – 0.97 0.96 0.97 0.98 0.97 0.78 0.86

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Table 4 Prolapse quality-of-life domain scores for symptomatic and asymptomatic women

Prolapse quality-of-life domain scores (median, IQR) Symptomatic (n=124) General health perceptions Prolapse impact Role limitation Physical limitation Social limitation Personal relationship Emotions Sleep/Energy Severity measures

Discussion It has been suggested that the management of women with urogenital prolapse should consider the severity of symptoms and their impact on QOL. Therefore, it is important to establish a valid and reliable disease-specific questionnaire to evaluate the QOL in these women as well as to evaluate the outcomes of POP surgery [17–22]. The P-QOL questionnaire is a “self-administered” questionnaire developed and validated in English-speaking women to evaluate the QOL of women with POP [1]. In the current study, we assessed validity and reliability of the Persian version of P-QOL. Our results demonstrated a good internal consistency of P-QOL domain scores. All Cronbach’s alpha were greater than 0.7, except for sleep/ energy domain. These findings were similar to the results of the other validation studies of P-QOL questionnaire [7–14]. In Slovakian [9] and Portuguese [10] studies, the “sleep energy” and “severity measures” domains had a low Cronbach’s

ROC Curve

Reference Line

1.00

severity measures

50 67 33 33 44 50 56 33 25

Asymptomatic (n=125)

(50–75) (33–67) (33–67) (33–67) (11–67) (33–67) (33–67) (17–50) (17–42)

50 0 0 0 0 0 0 0 0

(25–50) (0–0) (0–0) (0–0) (0–0) (0–0) (0–0) (0–0) (0–0)

alpha too. However, these domains had coefficients greater than the established satisfactory cutoff point of 0.7. In order to assess construct validity of the Persian version of the P-QOL questionnaire, we compared the domain scores with vaginal examination findings using POP-Q in symptomatic women. It was shown that the domain scores of P-QOL and POP-Q stages (vaginal examination) have a strong correlation, except for “personal relationship” and “Emotions.” The correlation between scores and vaginal finding in other studies [9, 10] was almost similar to our studies, ranging from 0.02–0.49 [10] and 0.2–0.69 [9], except for two mentioned domains. One explanation could be cultural differences between countries. This shows that the severity of POP has a minor effect on emotions and personal relationship of Persian women. The discriminant validation was evaluated with comparison of P-QOL domain scores between the symptomatic and asymptomatic women. The P-QOL domain scores were significantly higher among symptomatic than asymptomatic women, except for general health perceptions. This finding was similar to the Portuguese validation study [10]. This might be due to the effect of other medical conditions on this domain. However, in the original English version validation

Sleep/energy

Sensitivity

.75

Emotions Personal relationship

.50

Social limitations Physical limitation Role limitations

.25

Prolapse impact GHP

0.00 0.00

.25

.50

.75

1.00

1 - Specificity Diagonal segments are produced by ties.

Fig. 1 ROC of P-QOL domain scores between symptomatic and asymptomatic women

Table 5 Test–retest reliability coefficients for the P-QOL domain scores by SCC Prolapse quality-of-life domain scores

SCC

P value

General health perceptions Prolapse impact Role limitation Physical limitation Social limitation Personal relationship Emotions Sleep/Energy Severity measures

0.76 0.95 0.93 0.93 0.87 0.99 0.86 0.80 0.84

<0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001

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study [1] of P-QOL and the Italian one [14], this domain was significantly different between symptomatic and asymptomatic women. The test–retest reliability scores for the P-QOL were greater than 0.7 for all domain scores demonstrating a good reproducibility of the Persian questionnaire (Table 5). For assessing the validity of domain scores of P-QOL as a sensitive measure for presence or absence of disease, we also used ROC curve in order to distinguish between symptomatic and asymptomatic women. All domain scores had an area under curve which was significantly higher than the reference line. This further confirmed the discriminant validity of the Persian questionnaire. In conclusion, this validation study confirmed a good validity and reliability of the Persian version of P-QOL questionnaire. This tool can evaluate the severity and impact of POP on women’s QOL. This questionnaire can be easily administered, completed by women, and used before and after treatment of urogenital prolapse as a good indicator of treatment outcomes in Persian women in the future. Further studies are needed to evaluate the responsiveness of P-QOL. Acknowledgments Our special thanks to the head of the Department of Gynecology and Obstetrics, the Akbar-Abadi hospital, Maryam Kashanian M.D., and all gynecology and obstetric residents for their collaboration. Conflicts of interest None.

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