Asymptomatic bacteriuria in a population of elderly residents living in a community setting: prevalence, characteristics and associated factors

Background. Asymptomatic bacteriuria (ASB) is common among the elderly in institutional care, but less is known about its prevalence among the elderly living in community settings. Knowledge of the prevalence of ASB in this population could contribute to a reduction in unnecessary use of antibiotics. Objective. To study the prevalence of ASB and associated health and social factors in a population of elderly people, aged 80 and over, in a community setting. Design. A cross-sectional study. Setting. The catchment area of a primary health care centre in a Swedish middle-sized town. Method. All residents, aged 80 and over, except for those in institutional living, were invited. A structured interview was carried out and urinary culture obtained. Results. ASB was found in 14.8% of the participants, in 19.0% of the women and 5.8% of the men. In women independent associations with ASB were found for urinary incontinence (OR: 2.99, CI: 1.60-5.60), reduced mobility (OR: 2.68, CI: 1.42-5.03) and oestrogen treatment (OR: 2.20, CI: 1.09-4.45). Conclusion. Bacteriuria is common among the elderly living in non-institutional community settings, especially among women, although not as common as among the elderly in institutional settings. A woman over 80, with urinary incontinence, and needing support to walk has a risk of nearly 50% of presenting with ASB, a condition about which there is consensus not to treat with antibiotics. This should be borne in mind when examining patients with diffuse symptomatology and an accidental finding of bacteriuria.