Outpatient antidepressant utilization in a Dutch sick fund

To identify quality improvement opportunities in the management of depression by evaluating patterns of antidepressant use and concurrent use of anxiolytics or sedative/hypnotics among patients who initiated therapy with amitriptyline, fluoxetine, fluvoxamine, or paroxetine.

A longitudinal, retrospective study using electronic prescription data from a Dutch sick fund, ZAO Zorgverzekeringen.

The study patients (n = 2,554) initiated therapy between October 1, 1994 and December 31, 1995. Follow-up periods were 6 months (antidepressant use) and 60 days (concurrent anxiolytic and sedative/hypnotic use).

The three key findings were as follows: (1) the majority of patients received less than 4 months of therapy (more common for patients receiving amitriptyline); (2) the average daily doses for initial prescriptions for all four study drugs were below the recommended therapeutic minimums for depression (overall and final amitriptyline doses also were consistently low); and (3) the incidence of concurrent anxiolytic and sedative/hypnotic use during days 2-60 after antidepressant therapy initiation was 18.2%.

The study suggests that patients in this Dutch sick fund were not likely to receive either adequate antidepressant doses or adequate durations of therapy relative to Dutch guidelines for the treatment of depression. These findings are consistent with findings in other Dutch, European, and US studies and may present opportunities for quality improvement.