Health advisories and patterns of patient monitoring among new users of antidepressant medications.

INTRODUCTION: In 2003, more intense monitoring of patients initiating antidepressants was advised because of emerging concerns of suicidality. We sought to identify patterns of patient monitoring after antidepressant initiation in British Columbia before and after issuance of health advisories.
MATERIALS AND METHODS: We conducted a cohort study of antidepressant initiators between 1999 and 2005 using healthcare utilization data of all British Columbia residents. For the periods before (1999-2001) and after (2004-2005), health advisories concerning suicidality associated with antidepressants, we assessed monitoring intensity by calculating weekly physician and psychotherapy visit rates since antidepressant initiation. We also estimated monitoring patterns as the proportion of individuals who received weekly in-person contact during the first 4 weeks of treatment, then biweekly visits for 4 weeks, and then a visit at 12 weeks, as a proxy for intensive monitoring.
RESULTS: Patterns of monitoring intensity were similar before and after the health advisories, but the level of intensity was lower after the advisory period. Overall, monitoring intensity peaked in the 4 weeks after antidepressant initiation. Weekly numbers of visits per subject during these 4 weeks were between 0.44 and 0.49 before the advisory and from 0.39 to 0.44 after the advisory. Among all initiators stratified by year of initiation, between 21% and 25% received intensive monitoring, and this proportion generally decreased on a yearly basis. DISCUSSION: Monitoring intensity for patients with depression initiating antidepressants decreased after the period of emergence and greater awareness of the association between antidepressants and suicidality.