Measuring the incidence and prevalence of obstetric fistula: approaches, needs and recommendations

Perspectives Obstetric fistula – an abnormal connection between the vagina, rectum and/or bladder – may develop after prolonged and obstructed labour and lead to continuous urinary or faecal incontinence. Most fistulas occur in countries in sub-Saharan Africa or south Asia with poorly-resourced health systems. Women with obstetric fistula are indicators of the failure of health systems to deliver accessible, timely and appropriate intrapartum care. Incidence and prevalence measurements of obstetric fistula are needed to sustain interest in – and funding for – sustainable methods for prevention and treatment. Knowing the absolute numbers of women requiring treatment is also essential for effective health-care planning. Incidence and prevalence estimates of obstetric fistula are generally based on self-reporting, personal communication with surgeons, studies by advocacy groups and reviews of hospital services in which the relevant denominators are unknown or unreported. 1 The World Health Organization estimates that between 50 000 to 100 000 women worldwide develop obstetric fistula each year. 2 However, these estimates are based on scanty data and need to be updated. The relative rarity of obstetric fistula and the geographical remoteness of the areas where most cases occur mean that there are few reliable estimates of the number of women affected. A recent review of 19 studies attempted to estimate the global prevalence and incidence of obstetric fistula but could find very few studies that used a nationally-representative sample or were conducted in South Asia. 3 Data on the incidence of iatrogenic fistula – a complication of obstetric or gynaecologi-cal surgery – are also scarce. These cross-sectional prevalence studies and prospective and retrospective incidence studies have mostly used community or facility sampling or a combination of both. 3 Whatever the approach, it is important to report the methods used, the assumptions made and the strengths and limitations of these approaches. Facility-based studies of prevalence or incidence can be easier to conduct than community-based studies and provide opportunities for clinical assessments and accurate diagnoses. The combination of existing medical records and study-based observations often permits comprehensive data collection. Facility-based studies may be entirely retrospective – if medical records have been kept carefully 4 – or prospective. However, given the rarity of obstetric fistula, prospective studies may identify very few cases. 5 Facility-based studies are limited to women who access the facility. Women who do not access facilities are excluded from these studies. These are usually women in remote and rural areas …