[Reduction in the consumption of benzodiazepines due to a letter to chronic users from their own general...

To investigate the effectiveness of a minimal intervention in reducing the volume of prescription of benzodiazepines at the regional level.

Prospective.

Patients on compulsory health insurance who had received 180 or more daily doses of benzodiazepines in the course of one year received a letter from their general practitioner (GP) with information about the risks of chronic use, the advice to reduce or stop use, and an invitation to make an appointment to discuss the problem. This intervention took place in 19 GP practices in East Groningen. A reminder was sent six months later to the patients who had not responded in 9 randomly selected GP-practices. Thirty-seven practices in East Groningen and 91 practices in Northwest Groningen served as controls. Outcome measures were: (a) the percentage of patients who stopped, and (b) the change in average benzodiazepine consumption.

During the period 6-12 months after the first letter in the intervention group (n = 1343), 11.3% of the patients (95% CI: 9.6-13.1) received no prescription whatsoever for benzodiazepines compared to 5.4% (4.6-6.3) and 4.9% (4.2-5.5) in East Groningen (n = 2932) and in Northwest Groningen (n = 4562), respectively. The average decrease in prescription volume was 13% (-9.9 to -15.1) in the intervention group compared to 3% (-0.1 to -4.1) and 3% (-1.5 to -4) in the control groups. The reminder sent half a year later had no additional effect.

The informative letter from the GP to chronic users of benzodiazepines with the advice to stop or reduce this use was effective.