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%).