The Incontinence Quality of Life Instrument in a survey of primary care patients

,

Original Research

The Incontinence Quality of Life Instrument in a survey of primary care patients

J Fam Pract. 2002 November;51(11):1-1

By

Murray M. Finkelstein, MD, PhD, CCFP

PDF Download

References

1. Jeter KF, Wagner DB. Incontinence in the American home. A survey of 36,500 people. J Am Geriatr Soc 1990;38:379-83.

2. Ware JEJ. The status of health assessment 1994. Annu Rev Public Health 1995;16:327-54.

3. Shumaker SA, Wyman JF, Uebersax JS, McClish D, Fantl JA. Health-related quality of life measures for women with urinary incontinence: the Incontinence Impact Questionnaire and the Urogenital Distress Inventory. Continence Program in Women (CPW) Research Group. Qual Life Res 1994;3:291-306.

4. Uebersax JS, Wyman JF, Shumaker SA, McClish DK, Fantl JA. Short forms to assess life quality and symptom distress for urinary incontinence in women: the Incontinence Impact Questionnaire and the Urogenital Distress Inventory. Continence Program for Women Research Group. Neurourol Urodyn. 1995;14:131-9.

5. Wagner TH, Patrick DL, Bavendam TG, Martin ML, Buesching DP. Quality of life of persons with urinary incontinence: development of a new measure. Urology 1996;47:67-71.

6. Patrick DL, Martin ML, Bushnell DM, et al. Quality of life of women with urinary incontinence: further development of the incontinence quality of life instrument (I-QOL). Urology 1999;53:71-6.

7. Ware JJ, Kosinski M, Keller SD. A 12-Item Short-Form Health Survey: construction of scales and preliminary tests of reliability and validity. Med Care 1996;34:220-33.

8. Dillman DA. Mail and Telephone Surveys: The Total Design Method. New York: John Wiley & Sons; 1978.

9. Schafer JL. Analysis of Incomplete Multivariate Data. London: Chapman & Hall; 1997.

10. Rubin DL. Multiple Imputation for Nonresponse in Surveys. New York: John Wiley & Sons; 1987.

11. Honaker J, Joseph A, King G, Scheve K, Singh N. Amelia: a program for missing data. 2001. Available at: http://gking.harvard.edu/stats/shtml. Accessed September 30, 2002.

12. Hastie TJ, Tibshirani RJ. Generalized Additive Models. London: Chapman & Hall; 1990.

13. Freund RJ, Wilson WJ. Regression Analysis. San Diego: Academic Press; 1998.

14. van Erkel AR, Pattynama PM. Receiver operating characteristic (ROC) analysis: basic principles and applications in radiology. Eur J Radiol 1998;27:88-94.

15. Stata Statistical Software. Version 7.0. College Station, TX: StatCorp; 2000.

16. Fox J. Multiple and Generalized Nonparametric Regression. Thousand Oaks, CA: Sage Publications; 2000.

Address reprint requests to Murray M. Finkelstein, MD, PhD, Family Medicine Centre, Suite 413, Mt Sinai Hospital, Toronto, ON M5G 1X5, Canada. E-mail: murray.finkelstein@utoronto.ca.

To submit a letter to the editor on this topic, click here: jfp@fammed.uc.edu.

ABSTRACT

OBJECTIVE: To assess the performance of the Incontinence Quality of Life (I-QOL) Instrument in measuring the impact of urinary incontinence on the quality of life of family medicine patients.

STUDY DESIGN: Postal survey. Multiple imputation of missing answers. Linear regression analysis of I-QOL predictors. Comparison by receiver operating characteristic of the I-QOL and the Short Form 12 (SF-12).

POPULATION: Women 45 years or older attending either of 2 family medicine clinics. Response rate was 605 (61%) of 992.

OUTCOMES MEASURED: Prevalence of stress, urge, and mixed incontinence. Scores on the I-QOL and SF-12 instruments.

RESULTS: Of the 605 respondents, 310 (51%) reported urinary incontinence in the month before the survey. At least 1 item was missing on 19% of the I-QOL scales and scores were imputed. The relation between I-QOL and the number of leakage episodes was nonlinear. I-QOL scores decreased with the number of episodes, the amount of leakage, and poorer general health. There was no association between the I-QOL and age, education, or the type of incontinence. The I-QOL was more sensitive than the SF-12 to the statement that “urinary incontinence is a problem.”

CONCLUSIONS: The I-QOL is a useful instrument for the investigation of incontinence related quality of life in the community setting.

Urinary incontinence is a common problem among primary care patients.¹ In recent years, patient perceptions of quality of life have become increasingly important in the evaluation of health conditions and their treatment.² Specific instruments have been developed for the evaluation of the health-related quality of life of women reporting urinary incontinence.^3,4 Wagner and colleagues developed a self-report quality of life measure specific to urinary incontinence (the Incontinence Quality of Life Instrument; I-QOL) that could be used as an outcome measure in clinical trials and patient care centers.⁵ The developers tested the instrument on a sample of 62 subjects and reported that the I-QOL was more sensitive than a generic instrument, such as the Short Form 36 (SF-36), in detecting differences between levels of self-perceived incontinence severity. In a follow-up study,⁶ incontinent women (141 with stress and 147 with mixed urinary incontinence) completed the I-QOL and comparative instruments at screening, pretreatment, and 4 follow-up visits during participation in a randomized trial assessing the efficacy of a medication for incontinence. Those investigators reported that, in the clinical trial, the I-QOL proved to be valid, reproducible, and responsive to treatment for urinary incontinence in women.

The aim of our study was to measure the prevalence of urinary incontinence and its impact on quality of life, in a population of community dwelling women. We selected the I-QOL and the Short Form 12 (SF-12)⁷ as specific and generic instruments, respectively, for the measurement of quality of life among incontinent women. In this report we describe the performance of the I-QOL in the community setting.

METHODS

Subjects

The subjects were women 45 years or older who attended either of 2 participating family medicine clinics in the city of Hamilton, Ontario. This was a postal survey using a modified Dillman method.⁸ The Dillman method calls for 3 mailings and a reminder postcard. Because of budgetary constraints we planned an initial mailing, followed by a reminder postcard and a second mailing to nonrespondents. Our budget permitted a sample size of about 1000, so that questionnaires were sent to all eligible patients attending the smaller clinic and to a random sample drawn from the roster of the larger clinic.

The initial mailing was sent to 1082 women. Ninety envelopes were returned undeliverable; in addition, 115 women returned the survey but selected the option of nonparticipation. The final response rate was 605 (61%) of 992.

Survey questions

Two questions inquired about the presence of incontinence: (1) “During the past month have you ever experienced urine loss (wet yourself) when coughing, laughing, or doing some other activity?” (2) “During the past month have you ever had to pee and then wet yourself before getting to the toilet?” We classified incontinence as “stress incontinence” if respondents replied “yes” to question 1; as “urge incontinence” if they replied “yes” to question 2; and as “mixed incontinence” if they responded “yes” to both. In addition, we asked, “Is wetting yourself a problem that interferes with your day-to-day activities or bothers you in other ways?” We also inquired about the number of daytime and nighttime leaking episodes in an average week and the amount of wetness (underwear or pad only, outer clothing, urine runs down legs, or pools on floor). The survey included 2 health-related quality of life instruments, the I-QOL and the SF-12,⁷ a generic instrument.