Jourual of Epidemiology and Community Health 1993; 47: 497-499 Validation of a severity index in female urinary i e incontinence and its implementation in an epidemiological survey Hogne Sandvik, Steinar Hunskaar, Arnfinn Seim, Ragnar Hermstad, Anita Vanvik, Harald Bratt Division for General Practice, Department of Public Health and Primary Health Care, University of Bergen, Norway H Sandvik S Hunskaar 7100 Rissa, Norway A Seim R Hermstad Department of Gynecology and Obstetrics, Trondheim University Hospital, Norway A Vanvik H Bratt Correspondence to: Dr H Sandvik, Division for General Practice, I)epartment of Pulic Health and Primarv Health Care, University of Bergen, Ulriksdal 8c, N-5009 Bergen, Norway Accepted for publication June 1993 Abstract Study objective-The aim was to validate a simple severity index of female urinary incontinence for subsequent use in an epi- demiological survey. Design-The index was created by multi- plying the reported frequency (four levels) by the amount of leakage (two levels). The resulting index value (1-8) was further categorised into slight (1-2), moderate (3-4), and severe (6-8). It was validated against a 48 hour "pad weighing" test. Thereafter, an anonymous postal questionnaire survey was performed and the index was used to assess the severity of the leakage. A question about the impact ofincontinence was also included. Setting-The outpatient clinic of the Depart- ment of Gynaecology and Obstetrics, Trondheim University Hospital and the rural community of Rissa, Norway. Participants-Altogether 116 incontinent women referred to the clinic by their GP and all 2366 adult women living in Rissa. Results-The difference in median pad weights between moderate and slight incontinence was 9g/24h (95% confidence interval 0-27). The corresponding difference between severe and moderate incontinence was 17g/24h (95% CI 5-30). In the epidem- iological survey 29*4% reported urinary incontinence (response rate 77%). The prevalence tended to be highest in middle life and old age. Forty six per cent were classified as slight, 27% moderate, and 27% severe. There was a strong correlation between severity and impact (R=0.59, p<0-001). Conclusion-The severity index may be a useful tool for assessing the severity of female urinary incontinence in epidemiological sur- veys. It is confirmed that urinary incontinence is very prevalent in adult women, but most should not be regarded as potential patients. 7 Epidemziol Community Health 1993; 47: 497-499 Several epidemiological surveys of female urinary incontinence have been conducted over the years. 8Not all of these studies cover the com- plete adult age span, but many authors report a prevalence peak in middle life, followed by a decline, and then a subsequent rise in old age. 1-4 The actual prevalence numbers vary widely, how- ever, even in the same age group. Prevalence estimates in women aged 45-54 years vary from approximately 16%0 to 60%?. Epidemiological surveys of urinary incontinence usually rely on data collected through ques- tionnaires or interviews. Some sort of classification by severity is often used in these studies, 1 5 89 but the validity of the criteria is uncertain. In addition, different criteria are used by different authors, making comparisons even more difficult. According to the Intemational Continence Society, urinary incontinence is defined as involuntary loss of urine, which is objectively demonstrable and a social or hygiene problem.'0 The important aspect of severity is not included in this definiton. There are indications, however, that most incontinent women do not perceive their condition as a major problem.8 The overwhelmingly high prevalence numbers often cited represent a challenge for health services. Planning of optimal incontinence care means that the real extent of the problem needs to be carefully investigated. Severity and impact are key issues in this respect. This study was designed to validate a simple severity index for female urinary incontinence. Furthermore, we wanted to implement this index in an epidemiological survey of the general popula- tion, including adult women of all ages and those living in institutions. Methods VALIDATION STUDY The first part of the study was conducted during the years 1988-92 at the outpatient clinic of the Department of Gynaecology and Obstetrics, Trondheim University Hospital. All women referred by GPs because of urinary incontinence were included. Before proceeding to other diag- nostic procedures all patients were interviewed in a standard fashion by a nurse using a structured questionnaire designed for the study. A severity index was created by multiplying the reported frequency (four levels) by the amount of leakage (two levels) (table I). The resulting index value (1-8) was further categorised into slight (1-2), moderate (3-4), and severe (6-8). Typically, slight incontinence denotes leakage of drops a few times a month, moderate incontinence daily leak- age of drops, and severe incontinence larger amounts at least once a week. A pad weighing test was performed at home by approximately half of the patients. They had been provided with 12 medium sized pads and instructed to wear a preweighed pad day and night during a 48 hour period. They were to change pads when required, but before disposal the pads were reweighed and the weight gain noted. Some women interrupted the pad weighing test after 24 on June 15, 2020 by guest. Protected by copyright. http://jech.bmj.com/ J Epidemiol Community Health: first published as 10.1136/jech.47.6.497 on 1 December 1993. Downloaded from