Development and validation of a screening tool to identify anal incontinence in women of reproductive age

Abstract

Anal incontinence is a debilitating condition projected to increase by 2030 to 1,835,340 Australian people, of which 1,122,749 will be women. Multiple risk factors are associated with anal incontinence. Pregnancy and childbirth are considered the main risk factors with subsequent pregnancies and childbirth compounding injuries and worsening symptoms. There is a high prevalence of incontinence but poor reporting across the lifespan for women of reproductive age. Furthermore, there is little evidence that specific screening or screening tools exist for pregnant or postnatal women especially in the first trimester of pregnancy, where the initial planning and management for care has commenced and can reduce worsening symptoms. To address the gaps in clinical practice, this thesis used a mixed method research design, which included four stages of research to explore the factors that influence the disclosure of anal incontinence in women of reproductive age. This approach assisted in the development and validation of a bowel-screening tool (BSQ). Qualitative research methods complemented and informed quantitative research findings, identifying omissions or misunderstanding of terms within current screening tools and assisted in the development of the new tool. The thesis findings established an overall high prevalence of anal incontinence. These findings are comparable to other studies that included rectal urgency. These findings differ to previous studies that report lower rates, largely because of the different clinical screening tools used, study sample and size, and how incontinence was determined. The benefits of consumer participation in the development of the BSQ improved disclosure through the identification of symptoms and the transient nature of incontinence, which were important for women. Qualitative findings established further roadblocks for disclosure through the lack of screening by health professionals and difficulty comprehending screening tools. There was a significant disparity between the BSQ and clinical tools previously used, largely because of poor comprehension and symptom omission in tools. The BSQ reported a high prevalence of anal incontinence across all stages of the research (range 26% to 68%). The screening tool identified that there was varied reporting of the symptoms of anal incontinence both in the past and during current screening of antenatal (68% vs 12.9%) and community women (5.1% vs 34.5%). Symptoms were less frequent in the current period for antenatal women suggesting that early pregnancy may alter the incidence of symptoms. The findings suggest that flatus, soiling and rectal urgency were predominant symptoms across both timeframes. These symptoms are known precursors for worsening function with subsequent births. Other obstetric factors, including caesarean section, second-degree perineal tear, intact perineum, ageing and increased body mass index, were also associated with incontinence. Ageing and increased body mass index were associated with incontinence and predominant factors in all stages of the research. The relative risk of experiencing anal incontinence increased with a yearly increase in age (OR = 1.02; 95% CI: 1.00, 1.05; P value = 0.0690). An increase by one unit on the body mass index further increased a woman’s risk by 2% (OR = 1.02; 95% CI: 0.98, 1.05; P value = 0.3534). Over half the research participants (53%) were overweight with 32% of women with a BMI of 30 or more (obese). The risk of incontinence is heightened in obese women as they are more likely to have obstetric complications such as high blood pressure, gestational diabetes, larger babies, risk of instrumental delivery, perineal trauma and in particular, OASIS. This work has identified a higher reporting of historical incontinence by antenatal women compared with women in the community. It has also reinforced that the aetiology of anal incontinence might be multifactorial, with factors other than birth trauma and direct injury to the anal sphincter, being associated with incontinence. These findings are similar to those reported in studies that recognise the influence of additional pre-pregnancy, and pregnancy factors, rather than just the consequences of labour and birth. The prevalence of incontinence and the variability of symptoms is high in women of reproductive age. The BSQ can be used as a primary and secondary prevention strategy in clinical settings for early screening of at risk women through the identification of pre-existing symptoms, which may be overlooked in women who present with no current symptoms.