- Email: [email protected]
Reliability and validity of a Chinese version of the Modified Body Image Scale in patients with symptomatic pelvic organ prolapse
International Journal of Gynecology and Obstetrics 130 (2015) 187–189
Contents lists available at ScienceDirect
International Journal of Gynecology and Obstetrics journal homepage: www.elsevier.com/locate/ijgo
CLINICAL ARTICLE
Reliability and validity of a Chinese version of the Modified Body Image Scale in patients with symptomatic pelvic organ prolapse Lan Zhu a,⁎, Xiaoqian Wang a, Honghui Shi a, Tao Xu b, Jinghe Lang a, Xiang Tang a a b
Department of Obstetrics and Gynecology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China Department of Epidemiology and Statistics, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, Beijing, China
a r t i c l e
i n f o
Article history: Received 27 June 2014 Received in revised form 23 February 2015 Accepted 24 April 2015 Keywords: Pelvic organ prolapse Modified Body Image Scale Reliability Validity Sexual function
a b s t r a c t Objective: To validate a Chinese version of the Modified Body Image Scale (MBIS) among patients with symptomatic pelvic organ prolapse. Methods: As part of a validation study at a center in Beijing, China, women with symptomatic pelvic organ prolapse stage II or greater completed the Chinese version of the MBIS, the 12-item Short-Form Health Survey (SF-12), and the Pelvic Organ Prolapse/Urinary Incontinence Sexual Questionnaire (PISQ-12). A sample of 30 women was randomly chosen to return 2 weeks later to complete the questionnaires again. The reliability and validity of the MBIS were assessed. Results: Overall, 52 patients participated. A Cronbach α of 0.926 demonstrated adequate internal consistency of the Chinese MBIS. Its reproducibility was demonstrated by intraclass correlation coefficient values of 0.554–0.963 (P b 0.01 for all items). Confirmatory factor analysis supported its construct validity. The MBIS and SF-12 scores were negatively correlated (r = –0.390; P b 0.001), and the MBIS and PISQ-12 scores were also negatively correlated (r = –0.709; P b 0.001). Conclusion: The Chinese version of the MBIS is a reliable and valid tool to evaluate body image perception among patients with symptomatic pelvic organ prolapse. © 2015 Published by Elsevier Ireland Ltd. on behalf of International Federation of Gynecology and Obstetrics.
1. Introduction Pelvic organ prolapse (POP) is a disorder of the female reproductive system. The prevalence increases with age, and the symptoms affect millions of women. Approximately 11% of women with POP are expected to have surgery for prolapse or unitary incontinence, and one-third of these surgeries are repeated procedures [1]. Outcome evaluations of symptoms and treatments for POP should include objective and subjective measures—e.g. satisfaction, distress related to symptoms, quality of life (QOL), and the patient’s goals for treatment—which probably also encompass sexual function and body image [2,3]. The symptoms of POP—e.g. vaginal bulges, pelvic heaviness, and voiding dysfunction— and their treatment can change a patient’s physical appearance [4]. Psychological factors, such as body image perception, could be more important for sexual function than are the anatomical changes due to POP [5]. Only a few scales evaluate body image perception. The Body Image Scale (BIS)—which was developed and validated in patients with breast cancer, and was designed to apply to various types of cancer [6]— includes 10 questions that assess a person’s feelings regarding changes in appearance as a consequence of disease. In a modified version of ⁎ Corresponding author at: Department of Obstetrics and Gynecology, Peking Union Medical College Hospital, No. 1 Shuaifuyuan Road, Beijing, 100730, China. Tel.: + 86 10 69156784; fax: + 86 10 65124875. E-mail address: [email protected] (L. Zhu).
the BIS for use in patients with POP—the Modified Body Image Scale (MBIS) [7]—two questions from the BIS are omitted (“Have you been feeling the treatment has left your body less whole?” and “Have you been dissatisfied with the appearance of your scar?”), leaving eight questions that assess body image changes in patients with symptomatic POP. The questionnaire has high internal consistency, test–retest reliability, discriminant validity, and sensitivity to change [7,8]. Symptoms are assessed as present or absent by grading them from 0 (not at all) to 3 (very much). Overall scores range from 0 to 24; higher scores correspond to a lower body image. The MBIS is a validated questionnaire and has been widely applied in clinical trials [4,7–9]. Although there are Chinese versions of several relevant QOL questionnaires, such as short forms of the Pelvic Floor Impact Questionnaire (PFIQ-7) and the Pelvic Organ Prolapse/Urinary Incontinence Sexual Questionnaire (PISQ-12), there are no validated Chinese questionnaires that evaluate the severity of POP, treatments, and their effects on a patient’s body image perception [10,11]. The aim of the present study was to validate a Chinese version of the MBIS for patients with symptomatic POP. 2. Materials and methods The present validation study was conducted between October 1, 2011, and September 30, 2013. Patients were recruited from the gynecologic clinic of Peking Union Medical College Hospital, Beijing, China.
http://dx.doi.org/10.1016/j.ijgo.2015.03.026 0020-7292/© 2015 Published by Elsevier Ireland Ltd. on behalf of International Federation of Gynecology and Obstetrics.
188
L. Zhu et al. / International Journal of Gynecology and Obstetrics 130 (2015) 187–189
Eligible patients were aged 18 years or more, had POP of stage II or worse as measured by the Pelvic Organ Prolapse Quantification system [12], had at least one symptom associated with POP, had had no previous pelvic/gynecologic surgery, were heterosexual, had been sexually active within the past 6 months, and had no other major disabling medical or psychiatric condition. Women provided written consent before participating in any study-related procedures. The protocol for validation followed all local ethics and legal guidelines and was authorized by the Ethics Committee of Peking Union Medical College Hospital, Beijing, China. At a first visit, the patients were assessed by the attending physician. Measures, including demographic variables (e.g. age, marital status, education, and occupation), were recorded. At the end of the visit, the participants completed three questionnaires: the MBIS, the 12-item Short-Form Health Survey (SF-12), and the PISQ-12. The MBIS was the core test; the SF-12 and PISQ-12 were administered to explore the criterion validity of the MBIS. Permission to culturally adapt and validate the MBIS in the Chinese language was obtained from the author of the MBIS [7]. The original English MBIS was translated into Chinese and linguistically validated in line with recommendations for the cross-cultural adaptation of health-related quality of life (HRQOL) measures [13]. Two bilingual experts independently translated the MBIS into Chinese. The translators met with clinical experts in the specialty to ensure clinically appropriate wording of the questions, and the test was then taken by 10 patients with symptomatic POP. These patients were asked about the questions in the MBIS to ensure that they understood the items and that there was no semantic ambiguity. Next, two bilingual experts who were not familiar with the original version of the MBIS translated the Chinese version back into English, and a monolingual expert compared this backtranslated English version with the original version for accuracy and content. On the basis of their comments, all necessary modifications were made, and the final Chinese version of the MBIS was derived. The test was then administered to 10 healthy women. The average testing time was 5 minutes. In the Chinese version of the MBIS, the symptoms are assessed as present or absent by grading them from 0 (not at all) to 3 (very much). The scores range from 0 to 24; higher scores correspond to a lower body image. The SF-12 questionnaire is designed to assess the general health status and is the short form of the 36-item Short-Form Health Survey. It has been translated into Chinese and validated in a Chinese population [14]. The SF-12 is composed of eight subscales: physical function, physical role limitations, bodily pain, general health, vitality, social function, emotional role limitations, and mental health. Higher SF-12 scores indicate a better HRQOL. The PISQ-12 includes level B evidence and is recommended by the International Continence Society [2]. It is the most commonly used validated questionnaire to evaluate sexual function in patients with pelvic floor dysfunction in high-income countries [15]. The PISQ-12 contains 12 items and assesses three dimensions of sexual health: physical, emotional, and partner-related. Questions 1–4 are scored from 0 (never) to 4 (always), and questions 5–12 are scored from 0 (always) to 5 (never). A higher total score indicates better sexual function. The reliability and validity of the Chinese version of PISQ-12 has been established [11]. Thirty patients were identified through simple random sampling and asked to return to the clinic 2 weeks after the first visit to complete the questionnaires again. The two sets of answers were used to evaluate the test–retest reliability. No treatment was offered during the 2 weeks. The questionnaires were scored according to the developers’ guidelines. Statistical analyses were performed using SPSS version 17.0 (SPSS Inc, Chicago, IL, USA) and SAS version 9.1.3 (SAS Institute, Cary, NC, USA). All statistical tests were selected a priori, two-tailed, and conducted with a type I error probability fixed at 0.05. No data imputations were performed for missing data.
The internal consistency of the Chinese version of the MBIS was assessed by calculating Cronbach α, which was applied to assess the correlation between the adjusted questionnaire when one item was deleted and the total item questionnaire (corrected item-total correlation; Cronbach α N 0.70 was considered to demonstrate adequate internal consistency) [16]. To further evaluate the reliability of the Chinese version of the MBIS, the test–retest reliability was assessed by calculating the intraclass correlation coefficient (ICC; the test–retest reliability was considered to be excellent if ICC N 0.75, moderate if 0.4 ≤ ICC ≤ 0.75, and poor if ICC b0.4). The ICC is a preferred correlation coefficient for evaluation of the time stability of an instrument. The Wilcoxon signed-rank test was applied to investigate differences between two surveys. P b 0.05 was considered statistically significant. Confirmatory factor analysis was performed to determine whether the factor structure of the Chinese version of the MBIS was similar to that of the original version. The appropriateness of the use of confirmatory factor analysis was verified by calculating the Kaiser–Meyer–Olkin measure of sampling adequacy and performing the Bartlett test (P b 0.001). To explore the criterion validity (a measure of the correlation of an instrument with an established criterion standard), the Spearman correlations between the Chinese version of the MBIS and the SF-12 and PISQ-12 were calculated (an r value of 0.3–0.5 indicated moderate correlation; an r value of 0.5–0.7 indicated pronounced correlation; and an r value of 0.7–0.9 indicated strong correlation). 3. Results A total of 52 patients with symptomatic POP met the inclusion criteria and participated in the study. All 52 patients completed the three questionnaires during their initial visit, and 29 women completed the questionnaires a second time 2 weeks later (one patient selected to return was lost to follow-up because of a traffic problem). The mean age of the participants was 55.4 ± 8.3 years, and mean parity was 3.1 ± 1.5. Of the 52 women, 29 (56%) were postmenopausal, 18 (35%) were perimenopausal (from age 45 years to 12 months after menopause began), and 5 (10%) were premenopausal. The overall Cronbach α value of the MBIS was 0.926, indicating adequate internal consistency. The corrected item-total correlations in the whole sample ranged from 0.53 to 0.87. For all items except item 1, the α value did not increase when the item was deleted (Table 1). The ICC ranged from 0.554 to 0.963 (P b 0.01 for all items), and the results of the two MBIS surveys were not significantly different (P N 0.05), as illustrated by the Wilcoxon signed-rank test (Table 2). These findings showed that the Chinese version of the MBIS had adequate stability of scores over time. The appropriateness of the use of factor analysis was verified by both the Kaiser–Meyer–Olkin measure of sampling adequacy (0.806) and the Bartlett test (P b 0.001). Confirmatory factor analysis demonstrated a single-factor solution with an eigenvalue of 5.328, explaining 66.604% of the variance (Table 3). These findings were highly consistent with those for the original English scale [7,17].
Table 1 Descriptive analysis and internal consistency of the Chinese version of the Modified Body Image Scale. Item
Score (n = 52)a
Possible range of scores
Corrected item-total correlation
Cronbach α if item is deleted
1 2 3 4 5 6 7 8
2.55 ± 0.61 2.38 ± 0.59 2.30 ± 0.57 2.25 ± 0.55 2.25 ± 0.58 2.57 ± 0.60 2.50 ± 0.57 2.46 ± 0.60
0–3 0–3 0–3 0–3 0–3 0–3 0–3 0–3
0.53 0.78 0.82 0.83 0.77 0.74 0.71 0.87
0.933 0.914 0.910 0.910 0.913 0.917 0.918 0.910
a
Values are given as mean ± SD.
L. Zhu et al. / International Journal of Gynecology and Obstetrics 130 (2015) 187–189 Table 2 Reproducibility of the Chinese version of the Modified Body Image Scale. Item
1 2 3 4 5 6 7 8
Score (n = 29)a 1st survey
2nd survey
2.59 ± 0.501 2.38 ± 0.494 2.41 ± 0.501 2.34 ± 0.484 2.31 ± 0.541 2.66 ± 0.484 2.48 ± 0.509 2.45 ± 0.506
2.66 ± 0.484 2.34 ± 0.484 2.34 ± 0.553 2.21 ± 0.559 2.10 ± 0.900 2.45 ± 0.686 2.38 ± 0.677 2.21 ± 0.744
Possible range of scores
P valueb
ICC
0–3 0–3 0–3 0–3 0–3 0–3 0–3 0–3
0.157 0.317 0.317 0.194 0.084 0.063 0.334 0.035
0.926 0.963 0.859 0.554 0.789 0.715 0.637 0.758
Abbreviation: ICC, intraclass correlation coefficient. a Values are given as mean ± SD. b Wilcoxon signed-rank test.
Table 3 Confirmatory factor analysis of the Chinese version of the Modified Body Image Scale. Item
1 2 3 4 5 6 7 8
Initial eigenvalues
189
Chinese, the Chinese version of the MBIS was expected to show equivalent reliability and validity to the English version. The present results support this hypothesis: the Chinese version of the MBIS had sufficient reliability and validity to be used with Mandarin-speaking patients with symptomatic POP. The present study also evaluated the correlation between body image and sexual function in patients with symptomatic POP. The total scores of the MBIS were negatively correlated with the PISQ-12 scores, with a Spearman r value of –0.709 (indicating a strong correlation). This result confirms that women with a poorer body image had poorer sexual function. In conclusion, the present study indicates that the Chinese version of the MBIS is a psychometrically sound measure for the evaluation of body image concerns among women with symptomatic POP, just like the original English version, and that it is suitable for use in clinical and research settings.
Conflict of interest
Extraction sums of squared loadings
Total
% of variancea
Cumulative %b
Total
% of variancea
Cumulative %b
5.328 0.898 0.570 0.426 0.307 0.234 0.186 0.050
66.604 11.230 7.129 5.323 3.837 2.930 2.326 0.621
66.604 77.834 84.963 90.286 94.123 97.053 99.379 100.000
5.328 — — — — — — —
66.604 — — — — — — —
66.604 — — — — — — —
a
Percentage of variance accounted for by a given item. Cumulative percentage of variance accounted for by the current and all preceding items. b
Spearman correlation analysis showed that the scores on the Chinese version of the MBIS were negatively correlated with those on the SF-12, with a Spearman r value of –0.390 (indicating moderate correlation; P b 0.001). On the SF-12, higher scores indicate a better HRQOL, whereas higher scores on the MBIS demonstrate the opposite. Thus, the negative correlation between these two tests confirmed the original assumption that women with a poor body image had a worse HRQOL. The scores on the MBIS were also negatively correlated with those on the PISQ-12, with a Spearman r value of –0.709 (indicating a strong correlation; P b 0.001). On the PISQ-12, a higher score indicates better sexual function, whereas a higher total score on the MBIS indicates the opposite, meaning that the negative correlation was also in agreement with the original assumption that women with a poorer body image had poorer sexual function. These findings demonstrate that the Chinese version of the MBIS had moderate to excellent criterion validity. 4. Discussion The present study has validated a Chinese version of the MBIS in the field of pelvic flood dysfunction. The validation process included the cross-cultural adaptation of HRQOL measures. The questionnaires used in the specialty of pelvic floor dysfunction—including the PFIQ-7, PISQ-12, and MBIS—were initially developed in English and are widely used in high-income countries [7, 15,18]. The PFIQ-7 and PISQ-12 have been successfully translated into and validated in Chinese, Spanish, and French [10,11,19,20]. For the MBIS, the current Chinese version is its first validated translation. The Chinese version of the MBIS can be completed by patients in approximately 10 minutes, which makes it practical and efficient to administer in conjunction with other relevant questionnaires. Because the translation and validation procedures were identical to those used for the cultural adaptation and validation of other instruments into
The authors have no conflicts of interest.
References [1] Maher C, Feiner B, Baessler K, Schmid C. Surgical management of pelvic organ prolapse in women. Cochrane Database Syst Rev 2013;4:CD004014. [2] Barber MD. Questionnaires for women with pelvic floor disorders. Int Urogynecol J Pelvic Floor Dysfunct 2007;18(4):461–5. [3] Lowenstein L, FitzGerald MP, Kenton K, Dooley Y, Templehof M, Mueller ER, et al. Patient-selected goals: the fourth dimension in assessment of pelvic floor disorders. Int Urogynecol J Pelvic Floor Dysfunct 2008;19(1):81–4. [4] Lowenstein L, Gamble T, Sanses TV, van Raalte H, Carberry C, Jakus S, et al. Sexual function is related to body image perception in women with pelvic organ prolapse. J Sex Med 2009;6(8):2286–91. [5] FitzGerald MP, Kenton K, Shott S, Brubaker L. Responsiveness of quality of life measurements to change after reconstructive pelvic surgery. Am J Obstet Gynecol 2001; 185(1):20–4. [6] Hopwood P, Fletcher I, Lee A, Al Ghazal S. A body image scale for use with cancer patients. Eur J Cancer 2001;37(2):189–97. [7] Jelovsek JE, Barber MD. Women seeking treatment for advanced pelvic organ prolapse have decreased body image and quality of life. Am J Obstet Gynecol 2006; 194(5):1455–61. [8] Lowenstein L, Gamble T, Sanses TV, van Raalte H, Carberry C, Jakus S, et al. Changes in sexual function after treatment for prolapse are related to the improvement in body image perception. J Sex Med 2010;7(2 Pt 2):1023–8. [9] Patel MS, Mellen C, O'Sullivan DM, Lasala CA. Pessary use and impact on quality of life and body image. Female Pelvic Med Reconstr Surg 2011;17(6):298–301. [10] Zhu L, Yu S, Xu T, Yang X, Lu Y, Li B, et al. Chinese validation of the Pelvic Floor Impact Questionnaire Short Form. Menopause 2011;18(9):1030–3. [11] Zhu L, Yu S, Xu T, Yang X, Lu Y, Lang J. Validation of the Chinese version of the Pelvic Organ Prolapse/Urinary Incontinence Sexual Questionnaire short form (PISQ-12). Int J Gynecol Obstet 2012;116(2):117–9. [12] Bump RC, Mattiasson A, Bø K, Brubaker LP, DeLancey JO, Klarskov P, et al. The standardization of terminology of female pelvic organ prolapse and pelvic floor dysfunction. Am J Obstet Gynecol 1996;175(1):10–7. [13] Guillemin F. Cross-cultural adaptation and validation of health status measures. Scand J Rheumatol 1995;24(2):61–3. [14] Lam CL, Tse EY, Gandek B. Is the standard SF-12 health survey valid and equivalent for a Chinese population? Qual Life Res 2005;14(2):539–47. [15] Rogers RG, Coates KW, Kammerer-Doak D, Khalsa S, Qualls C. A short form of the Pelvic Organ Prolapse/Urinary Incontinence Sexual Questionnaire (PISQ-12). Int Urogynecol J Pelvic Floor Dysfunct 2003;14(3):164–8. [16] Cronbach LF. Coefficient alpha and the internal structure of tests. Psychometrika 1951;16(3):297–334. [17] Moreira H, Silva S, Marques A, Canavarro MC. The Portuguese version of the body image scale (BIS) - psychometric properties in a sample of breast cancer patients. Eur J Oncol Nurs 2010;14(2):111–8. [18] Barber MD, Kuchibhatla MN, Pieper CF, Bump RC. Psychometric evaluation of 2 comprehensive condition-specific quality of life instruments for women with pelvic floor disorders. Am J Obstet Gynecol 2001;185(6):1388–95. [19] Romero AA, Hardart A, Kobak W, Qualls C, Rogers R. Validation of a Spanish version of the Pelvic Organ Prolapse Incontinence Sexual Questionnaire. Obstet Gynecol 2003;102(5 Pt 1):1000–5. [20] Fatton B, Letouzey V, Lagrange E, Mares P, Jacquetin B, de Tayrac R. Validation of a French version of the short form of the Pelvic Organ Prolapse/Urinary Incontinence Sexual Questionnaire (PISQ-12). J Gynecol Obstet Biol Reprod (Paris) 2009;38(8): 662–7.
Contents lists available at ScienceDirect
International Journal of Gynecology and Obstetrics journal homepage: www.elsevier.com/locate/ijgo
CLINICAL ARTICLE
Reliability and validity of a Chinese version of the Modified Body Image Scale in patients with symptomatic pelvic organ prolapse Lan Zhu a,⁎, Xiaoqian Wang a, Honghui Shi a, Tao Xu b, Jinghe Lang a, Xiang Tang a a b
Department of Obstetrics and Gynecology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China Department of Epidemiology and Statistics, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, Beijing, China
a r t i c l e
i n f o
Article history: Received 27 June 2014 Received in revised form 23 February 2015 Accepted 24 April 2015 Keywords: Pelvic organ prolapse Modified Body Image Scale Reliability Validity Sexual function
a b s t r a c t Objective: To validate a Chinese version of the Modified Body Image Scale (MBIS) among patients with symptomatic pelvic organ prolapse. Methods: As part of a validation study at a center in Beijing, China, women with symptomatic pelvic organ prolapse stage II or greater completed the Chinese version of the MBIS, the 12-item Short-Form Health Survey (SF-12), and the Pelvic Organ Prolapse/Urinary Incontinence Sexual Questionnaire (PISQ-12). A sample of 30 women was randomly chosen to return 2 weeks later to complete the questionnaires again. The reliability and validity of the MBIS were assessed. Results: Overall, 52 patients participated. A Cronbach α of 0.926 demonstrated adequate internal consistency of the Chinese MBIS. Its reproducibility was demonstrated by intraclass correlation coefficient values of 0.554–0.963 (P b 0.01 for all items). Confirmatory factor analysis supported its construct validity. The MBIS and SF-12 scores were negatively correlated (r = –0.390; P b 0.001), and the MBIS and PISQ-12 scores were also negatively correlated (r = –0.709; P b 0.001). Conclusion: The Chinese version of the MBIS is a reliable and valid tool to evaluate body image perception among patients with symptomatic pelvic organ prolapse. © 2015 Published by Elsevier Ireland Ltd. on behalf of International Federation of Gynecology and Obstetrics.
1. Introduction Pelvic organ prolapse (POP) is a disorder of the female reproductive system. The prevalence increases with age, and the symptoms affect millions of women. Approximately 11% of women with POP are expected to have surgery for prolapse or unitary incontinence, and one-third of these surgeries are repeated procedures [1]. Outcome evaluations of symptoms and treatments for POP should include objective and subjective measures—e.g. satisfaction, distress related to symptoms, quality of life (QOL), and the patient’s goals for treatment—which probably also encompass sexual function and body image [2,3]. The symptoms of POP—e.g. vaginal bulges, pelvic heaviness, and voiding dysfunction— and their treatment can change a patient’s physical appearance [4]. Psychological factors, such as body image perception, could be more important for sexual function than are the anatomical changes due to POP [5]. Only a few scales evaluate body image perception. The Body Image Scale (BIS)—which was developed and validated in patients with breast cancer, and was designed to apply to various types of cancer [6]— includes 10 questions that assess a person’s feelings regarding changes in appearance as a consequence of disease. In a modified version of ⁎ Corresponding author at: Department of Obstetrics and Gynecology, Peking Union Medical College Hospital, No. 1 Shuaifuyuan Road, Beijing, 100730, China. Tel.: + 86 10 69156784; fax: + 86 10 65124875. E-mail address: [email protected] (L. Zhu).
the BIS for use in patients with POP—the Modified Body Image Scale (MBIS) [7]—two questions from the BIS are omitted (“Have you been feeling the treatment has left your body less whole?” and “Have you been dissatisfied with the appearance of your scar?”), leaving eight questions that assess body image changes in patients with symptomatic POP. The questionnaire has high internal consistency, test–retest reliability, discriminant validity, and sensitivity to change [7,8]. Symptoms are assessed as present or absent by grading them from 0 (not at all) to 3 (very much). Overall scores range from 0 to 24; higher scores correspond to a lower body image. The MBIS is a validated questionnaire and has been widely applied in clinical trials [4,7–9]. Although there are Chinese versions of several relevant QOL questionnaires, such as short forms of the Pelvic Floor Impact Questionnaire (PFIQ-7) and the Pelvic Organ Prolapse/Urinary Incontinence Sexual Questionnaire (PISQ-12), there are no validated Chinese questionnaires that evaluate the severity of POP, treatments, and their effects on a patient’s body image perception [10,11]. The aim of the present study was to validate a Chinese version of the MBIS for patients with symptomatic POP. 2. Materials and methods The present validation study was conducted between October 1, 2011, and September 30, 2013. Patients were recruited from the gynecologic clinic of Peking Union Medical College Hospital, Beijing, China.
http://dx.doi.org/10.1016/j.ijgo.2015.03.026 0020-7292/© 2015 Published by Elsevier Ireland Ltd. on behalf of International Federation of Gynecology and Obstetrics.
188
L. Zhu et al. / International Journal of Gynecology and Obstetrics 130 (2015) 187–189
Eligible patients were aged 18 years or more, had POP of stage II or worse as measured by the Pelvic Organ Prolapse Quantification system [12], had at least one symptom associated with POP, had had no previous pelvic/gynecologic surgery, were heterosexual, had been sexually active within the past 6 months, and had no other major disabling medical or psychiatric condition. Women provided written consent before participating in any study-related procedures. The protocol for validation followed all local ethics and legal guidelines and was authorized by the Ethics Committee of Peking Union Medical College Hospital, Beijing, China. At a first visit, the patients were assessed by the attending physician. Measures, including demographic variables (e.g. age, marital status, education, and occupation), were recorded. At the end of the visit, the participants completed three questionnaires: the MBIS, the 12-item Short-Form Health Survey (SF-12), and the PISQ-12. The MBIS was the core test; the SF-12 and PISQ-12 were administered to explore the criterion validity of the MBIS. Permission to culturally adapt and validate the MBIS in the Chinese language was obtained from the author of the MBIS [7]. The original English MBIS was translated into Chinese and linguistically validated in line with recommendations for the cross-cultural adaptation of health-related quality of life (HRQOL) measures [13]. Two bilingual experts independently translated the MBIS into Chinese. The translators met with clinical experts in the specialty to ensure clinically appropriate wording of the questions, and the test was then taken by 10 patients with symptomatic POP. These patients were asked about the questions in the MBIS to ensure that they understood the items and that there was no semantic ambiguity. Next, two bilingual experts who were not familiar with the original version of the MBIS translated the Chinese version back into English, and a monolingual expert compared this backtranslated English version with the original version for accuracy and content. On the basis of their comments, all necessary modifications were made, and the final Chinese version of the MBIS was derived. The test was then administered to 10 healthy women. The average testing time was 5 minutes. In the Chinese version of the MBIS, the symptoms are assessed as present or absent by grading them from 0 (not at all) to 3 (very much). The scores range from 0 to 24; higher scores correspond to a lower body image. The SF-12 questionnaire is designed to assess the general health status and is the short form of the 36-item Short-Form Health Survey. It has been translated into Chinese and validated in a Chinese population [14]. The SF-12 is composed of eight subscales: physical function, physical role limitations, bodily pain, general health, vitality, social function, emotional role limitations, and mental health. Higher SF-12 scores indicate a better HRQOL. The PISQ-12 includes level B evidence and is recommended by the International Continence Society [2]. It is the most commonly used validated questionnaire to evaluate sexual function in patients with pelvic floor dysfunction in high-income countries [15]. The PISQ-12 contains 12 items and assesses three dimensions of sexual health: physical, emotional, and partner-related. Questions 1–4 are scored from 0 (never) to 4 (always), and questions 5–12 are scored from 0 (always) to 5 (never). A higher total score indicates better sexual function. The reliability and validity of the Chinese version of PISQ-12 has been established [11]. Thirty patients were identified through simple random sampling and asked to return to the clinic 2 weeks after the first visit to complete the questionnaires again. The two sets of answers were used to evaluate the test–retest reliability. No treatment was offered during the 2 weeks. The questionnaires were scored according to the developers’ guidelines. Statistical analyses were performed using SPSS version 17.0 (SPSS Inc, Chicago, IL, USA) and SAS version 9.1.3 (SAS Institute, Cary, NC, USA). All statistical tests were selected a priori, two-tailed, and conducted with a type I error probability fixed at 0.05. No data imputations were performed for missing data.
The internal consistency of the Chinese version of the MBIS was assessed by calculating Cronbach α, which was applied to assess the correlation between the adjusted questionnaire when one item was deleted and the total item questionnaire (corrected item-total correlation; Cronbach α N 0.70 was considered to demonstrate adequate internal consistency) [16]. To further evaluate the reliability of the Chinese version of the MBIS, the test–retest reliability was assessed by calculating the intraclass correlation coefficient (ICC; the test–retest reliability was considered to be excellent if ICC N 0.75, moderate if 0.4 ≤ ICC ≤ 0.75, and poor if ICC b0.4). The ICC is a preferred correlation coefficient for evaluation of the time stability of an instrument. The Wilcoxon signed-rank test was applied to investigate differences between two surveys. P b 0.05 was considered statistically significant. Confirmatory factor analysis was performed to determine whether the factor structure of the Chinese version of the MBIS was similar to that of the original version. The appropriateness of the use of confirmatory factor analysis was verified by calculating the Kaiser–Meyer–Olkin measure of sampling adequacy and performing the Bartlett test (P b 0.001). To explore the criterion validity (a measure of the correlation of an instrument with an established criterion standard), the Spearman correlations between the Chinese version of the MBIS and the SF-12 and PISQ-12 were calculated (an r value of 0.3–0.5 indicated moderate correlation; an r value of 0.5–0.7 indicated pronounced correlation; and an r value of 0.7–0.9 indicated strong correlation). 3. Results A total of 52 patients with symptomatic POP met the inclusion criteria and participated in the study. All 52 patients completed the three questionnaires during their initial visit, and 29 women completed the questionnaires a second time 2 weeks later (one patient selected to return was lost to follow-up because of a traffic problem). The mean age of the participants was 55.4 ± 8.3 years, and mean parity was 3.1 ± 1.5. Of the 52 women, 29 (56%) were postmenopausal, 18 (35%) were perimenopausal (from age 45 years to 12 months after menopause began), and 5 (10%) were premenopausal. The overall Cronbach α value of the MBIS was 0.926, indicating adequate internal consistency. The corrected item-total correlations in the whole sample ranged from 0.53 to 0.87. For all items except item 1, the α value did not increase when the item was deleted (Table 1). The ICC ranged from 0.554 to 0.963 (P b 0.01 for all items), and the results of the two MBIS surveys were not significantly different (P N 0.05), as illustrated by the Wilcoxon signed-rank test (Table 2). These findings showed that the Chinese version of the MBIS had adequate stability of scores over time. The appropriateness of the use of factor analysis was verified by both the Kaiser–Meyer–Olkin measure of sampling adequacy (0.806) and the Bartlett test (P b 0.001). Confirmatory factor analysis demonstrated a single-factor solution with an eigenvalue of 5.328, explaining 66.604% of the variance (Table 3). These findings were highly consistent with those for the original English scale [7,17].
Table 1 Descriptive analysis and internal consistency of the Chinese version of the Modified Body Image Scale. Item
Score (n = 52)a
Possible range of scores
Corrected item-total correlation
Cronbach α if item is deleted
1 2 3 4 5 6 7 8
2.55 ± 0.61 2.38 ± 0.59 2.30 ± 0.57 2.25 ± 0.55 2.25 ± 0.58 2.57 ± 0.60 2.50 ± 0.57 2.46 ± 0.60
0–3 0–3 0–3 0–3 0–3 0–3 0–3 0–3
0.53 0.78 0.82 0.83 0.77 0.74 0.71 0.87
0.933 0.914 0.910 0.910 0.913 0.917 0.918 0.910
a
Values are given as mean ± SD.
L. Zhu et al. / International Journal of Gynecology and Obstetrics 130 (2015) 187–189 Table 2 Reproducibility of the Chinese version of the Modified Body Image Scale. Item
1 2 3 4 5 6 7 8
Score (n = 29)a 1st survey
2nd survey
2.59 ± 0.501 2.38 ± 0.494 2.41 ± 0.501 2.34 ± 0.484 2.31 ± 0.541 2.66 ± 0.484 2.48 ± 0.509 2.45 ± 0.506
2.66 ± 0.484 2.34 ± 0.484 2.34 ± 0.553 2.21 ± 0.559 2.10 ± 0.900 2.45 ± 0.686 2.38 ± 0.677 2.21 ± 0.744
Possible range of scores
P valueb
ICC
0–3 0–3 0–3 0–3 0–3 0–3 0–3 0–3
0.157 0.317 0.317 0.194 0.084 0.063 0.334 0.035
0.926 0.963 0.859 0.554 0.789 0.715 0.637 0.758
Abbreviation: ICC, intraclass correlation coefficient. a Values are given as mean ± SD. b Wilcoxon signed-rank test.
Table 3 Confirmatory factor analysis of the Chinese version of the Modified Body Image Scale. Item
1 2 3 4 5 6 7 8
Initial eigenvalues
189
Chinese, the Chinese version of the MBIS was expected to show equivalent reliability and validity to the English version. The present results support this hypothesis: the Chinese version of the MBIS had sufficient reliability and validity to be used with Mandarin-speaking patients with symptomatic POP. The present study also evaluated the correlation between body image and sexual function in patients with symptomatic POP. The total scores of the MBIS were negatively correlated with the PISQ-12 scores, with a Spearman r value of –0.709 (indicating a strong correlation). This result confirms that women with a poorer body image had poorer sexual function. In conclusion, the present study indicates that the Chinese version of the MBIS is a psychometrically sound measure for the evaluation of body image concerns among women with symptomatic POP, just like the original English version, and that it is suitable for use in clinical and research settings.
Conflict of interest
Extraction sums of squared loadings
Total
% of variancea
Cumulative %b
Total
% of variancea
Cumulative %b
5.328 0.898 0.570 0.426 0.307 0.234 0.186 0.050
66.604 11.230 7.129 5.323 3.837 2.930 2.326 0.621
66.604 77.834 84.963 90.286 94.123 97.053 99.379 100.000
5.328 — — — — — — —
66.604 — — — — — — —
66.604 — — — — — — —
a
Percentage of variance accounted for by a given item. Cumulative percentage of variance accounted for by the current and all preceding items. b
Spearman correlation analysis showed that the scores on the Chinese version of the MBIS were negatively correlated with those on the SF-12, with a Spearman r value of –0.390 (indicating moderate correlation; P b 0.001). On the SF-12, higher scores indicate a better HRQOL, whereas higher scores on the MBIS demonstrate the opposite. Thus, the negative correlation between these two tests confirmed the original assumption that women with a poor body image had a worse HRQOL. The scores on the MBIS were also negatively correlated with those on the PISQ-12, with a Spearman r value of –0.709 (indicating a strong correlation; P b 0.001). On the PISQ-12, a higher score indicates better sexual function, whereas a higher total score on the MBIS indicates the opposite, meaning that the negative correlation was also in agreement with the original assumption that women with a poorer body image had poorer sexual function. These findings demonstrate that the Chinese version of the MBIS had moderate to excellent criterion validity. 4. Discussion The present study has validated a Chinese version of the MBIS in the field of pelvic flood dysfunction. The validation process included the cross-cultural adaptation of HRQOL measures. The questionnaires used in the specialty of pelvic floor dysfunction—including the PFIQ-7, PISQ-12, and MBIS—were initially developed in English and are widely used in high-income countries [7, 15,18]. The PFIQ-7 and PISQ-12 have been successfully translated into and validated in Chinese, Spanish, and French [10,11,19,20]. For the MBIS, the current Chinese version is its first validated translation. The Chinese version of the MBIS can be completed by patients in approximately 10 minutes, which makes it practical and efficient to administer in conjunction with other relevant questionnaires. Because the translation and validation procedures were identical to those used for the cultural adaptation and validation of other instruments into
The authors have no conflicts of interest.
References [1] Maher C, Feiner B, Baessler K, Schmid C. Surgical management of pelvic organ prolapse in women. Cochrane Database Syst Rev 2013;4:CD004014. [2] Barber MD. Questionnaires for women with pelvic floor disorders. Int Urogynecol J Pelvic Floor Dysfunct 2007;18(4):461–5. [3] Lowenstein L, FitzGerald MP, Kenton K, Dooley Y, Templehof M, Mueller ER, et al. Patient-selected goals: the fourth dimension in assessment of pelvic floor disorders. Int Urogynecol J Pelvic Floor Dysfunct 2008;19(1):81–4. [4] Lowenstein L, Gamble T, Sanses TV, van Raalte H, Carberry C, Jakus S, et al. Sexual function is related to body image perception in women with pelvic organ prolapse. J Sex Med 2009;6(8):2286–91. [5] FitzGerald MP, Kenton K, Shott S, Brubaker L. Responsiveness of quality of life measurements to change after reconstructive pelvic surgery. Am J Obstet Gynecol 2001; 185(1):20–4. [6] Hopwood P, Fletcher I, Lee A, Al Ghazal S. A body image scale for use with cancer patients. Eur J Cancer 2001;37(2):189–97. [7] Jelovsek JE, Barber MD. Women seeking treatment for advanced pelvic organ prolapse have decreased body image and quality of life. Am J Obstet Gynecol 2006; 194(5):1455–61. [8] Lowenstein L, Gamble T, Sanses TV, van Raalte H, Carberry C, Jakus S, et al. Changes in sexual function after treatment for prolapse are related to the improvement in body image perception. J Sex Med 2010;7(2 Pt 2):1023–8. [9] Patel MS, Mellen C, O'Sullivan DM, Lasala CA. Pessary use and impact on quality of life and body image. Female Pelvic Med Reconstr Surg 2011;17(6):298–301. [10] Zhu L, Yu S, Xu T, Yang X, Lu Y, Li B, et al. Chinese validation of the Pelvic Floor Impact Questionnaire Short Form. Menopause 2011;18(9):1030–3. [11] Zhu L, Yu S, Xu T, Yang X, Lu Y, Lang J. Validation of the Chinese version of the Pelvic Organ Prolapse/Urinary Incontinence Sexual Questionnaire short form (PISQ-12). Int J Gynecol Obstet 2012;116(2):117–9. [12] Bump RC, Mattiasson A, Bø K, Brubaker LP, DeLancey JO, Klarskov P, et al. The standardization of terminology of female pelvic organ prolapse and pelvic floor dysfunction. Am J Obstet Gynecol 1996;175(1):10–7. [13] Guillemin F. Cross-cultural adaptation and validation of health status measures. Scand J Rheumatol 1995;24(2):61–3. [14] Lam CL, Tse EY, Gandek B. Is the standard SF-12 health survey valid and equivalent for a Chinese population? Qual Life Res 2005;14(2):539–47. [15] Rogers RG, Coates KW, Kammerer-Doak D, Khalsa S, Qualls C. A short form of the Pelvic Organ Prolapse/Urinary Incontinence Sexual Questionnaire (PISQ-12). Int Urogynecol J Pelvic Floor Dysfunct 2003;14(3):164–8. [16] Cronbach LF. Coefficient alpha and the internal structure of tests. Psychometrika 1951;16(3):297–334. [17] Moreira H, Silva S, Marques A, Canavarro MC. The Portuguese version of the body image scale (BIS) - psychometric properties in a sample of breast cancer patients. Eur J Oncol Nurs 2010;14(2):111–8. [18] Barber MD, Kuchibhatla MN, Pieper CF, Bump RC. Psychometric evaluation of 2 comprehensive condition-specific quality of life instruments for women with pelvic floor disorders. Am J Obstet Gynecol 2001;185(6):1388–95. [19] Romero AA, Hardart A, Kobak W, Qualls C, Rogers R. Validation of a Spanish version of the Pelvic Organ Prolapse Incontinence Sexual Questionnaire. Obstet Gynecol 2003;102(5 Pt 1):1000–5. [20] Fatton B, Letouzey V, Lagrange E, Mares P, Jacquetin B, de Tayrac R. Validation of a French version of the short form of the Pelvic Organ Prolapse/Urinary Incontinence Sexual Questionnaire (PISQ-12). J Gynecol Obstet Biol Reprod (Paris) 2009;38(8): 662–7.