Defining frequent attendance: evidence for routine age and sex correction in studies from primary care settings.

Primary care patients who attend significantly more frequently than the norm present a clinical challenge and implications for resource usage. However, studies are methodologically diverse in their definitions of frequent attendance, and do not always standardise for age and sex. This study shows that studies that do not correct for age and sex variations in consultation will miss a significant proportion of patients whose behaviour differs widely from their peers. It suggests a simple correction that could be utilised in primary care studies without requiring sophisticated statistical analyses.