Objective: To investigate whether the number of frequent attenders (FA) contacts with the out-of-hours service can be reduced by deploying a combination of intervention strategies.
Design: A stratified cluster randomized controlled trial, each cluster containing a general practice and all its listed patients.
Setting: The out-of-hours service in the county of Northern Jutland (490,000 inhabitants), Denmark.
Interventions: The following intervention strategies were deployed: predisposition, individual instruction, economic incitement, continuing medical education meetings, feedback/reminder, and patient-mediated intervention.
Subjects: An intervention group of 3500 patients and a control group of 4635 patients.
Main outcome measures: Absolute and relative fall in the number of contacts with the out-of-hours service per patient after 6 and 12 months.
Results: Analysed by group, intervention patients saw a more pronounced decline in the number of contacts than controls, except for two outcomes. However, this difference was only significant after 12 months. For women aged 17-66 years with 5-9 contacts during the previous 12 months, the decrease was significantly more pronounced in the intervention group for all outcomes (p=0.004-0.042). However, for the rest of the subgroups the effect varied more, and in several cases it was more distinct in the control group.
Conclusion: The data collected point towards an effect of intervention on the use of out-of-hours services even if the responses obtained were not uniform and unequivocal. However, one has to consider the problems of multiple comparisons and in conclusion no convincing effect of the intervention was found.