Frequent attendance in primary care: comparison and implications of different definitions.

BACKGROUND The diversity of definitions of frequent attendance in the literature hampers comparison of their precision, validity, and associated factors. AIM To examine different definitions of frequent attendance in order to identify the sociodemographic and clinical factors associated with frequent attendance in primary care, according to each definition. DESIGN OF STUDY One-phase cross-sectional study. SETTING Seventy-seven primary care centres in Catalonia, Spain. METHOD A total of 3815 primary care patients were interviewed between October 2005 and March 2006. Three definitions of frequent attendance were tested: (1) frequent attenders as the top 25% and the top 10% consulting patients; (2) frequent attenders as the top 25% and the top 10% consulting patients stratified by age and sex; and (3) frequent attenders as the top 25% and the top 10% consulting patients stratified by the presence of physical/mental conditions (patients with only mental disorders, with only chronic physical conditions, with comorbid conditions, and with no condition). Multilevel logistic regressions were used. RESULTS The following factors were systematically related to frequent attender status: being on sick leave, being born outside of Spain, reporting mental health problems as the main reason for consulting, and having arthritis/rheumatism, or bronchitis. Major depression was related to frequent attendance in two of the three definitions. The factor 'GP' was related to frequent attendance when the top decile cut-off point was used. The models with a 10% cut-off point were more discriminative than those with a 25% cut-off point: the area under the receiver operating characteristic curve for models with a 25% cut-off and a 10% cut-off ranged between 0.71 (95% confidence interval [CI] = 0.70 to 0.73) and 0.75 (95% CI = 0.74 to 0.77) and between 0.79 (95% CI = 0.78 to 0.81) and 0.85 (95% CI = 0.83 to 0.86), respectively. CONCLUSION The way frequent attendance is defined is of crucial importance. It is recommended that a more discriminative definition of frequent attendance is used (the top 10%).