Process evaluation of a cluster randomized trial of tailored interventions to implement guidelines in primary care -: why is it so hard to change practice?

Background. A cluster randomized trial of tailored interventions to support the implementation of guidelines for sore throat and urinary tract infection found little or no change in the main outcomes, which were antibiotic prescriptions, use of laboratory tests and use of telephone consultations. There was great variation between the practices in the change in these outcomes. Objectives. Our aim was to evaluate how the interventions were received and to understand why practices did or did not change. Methods. The trial was conducted in general practices in Norway. Data for this process evaluation were collected from the 120 practices that completed the trial. Multiple methods were used: observations, semi-structured telephone interviews, a postal survey and data extracted from electronic medical records. We investigated factors that might explain a lack of change, including: agreement with the guidelines; communication within each practice; degree of participation in the project; taking time to discuss the guidelines and their implementation; use of the components of the interventions; and routines for telephone consultations. Possible explanatory factors were explored in relation to variation in change and the overall extent of change in rates of use of antibiotics, laboratory tests and telephone consultations. Results. Sixty-three per cent of practices agreed with the guidelines. Only 35% reported having regular meetings, and 33% discussed the project before its start, although 75% reported agreement about participating within the practice. Only 33% reported meeting to discuss the guidelines. Use of the components of the interventions ranged from 11% for the increased fee for telephone consultations to 48% for the computerized decision support. Forty-four per cent reported problems with telephone routines. No single factor explained the observed variation in the extent of change across practices. Conclusions. Inadequate time, resources and support were the most salient factors that might explain a lack of change. Problems with internal communication and telephone routines were important contributing factors in many practices.