Assertive community treatment in veterans affairs settings: impact on adherence to antipsychotic medication

OBJECTIVES Assertive community treatment (ACT) programs may improve patients' outcomes, in part by increasing adherence to antipsychotic medication. This study assessed the association between ACT enrollment and subsequent antipsychotic adherence. METHODS The authors identified a national sample of 763 Veterans Affairs (VA) patients with schizophrenia who were newly enrolled in ACT in fiscal years 2001 to 2004 and had valid antipsychotic medication possession ratios (MPRs) for five sequential six-month periods, the first occurring before ACT enrollment. Propensity scores were used to match ACT patients 1:1 with eligible veterans who did not initiate ACT. Logistic regression analyses and generalized estimating equations (GEE) were used to assess the association between ACT enrollment and subsequent antipsychotic adherence. Antipsychotic adherence was compared among ACT enrollees with high, partial, or no participation in ACT services. RESULTS Before the index date, there was no significant difference in rates of good adherence (MPR ≥.8) among subsequent ACT enrollees (72%) and patients in the control group (70%). However, in each of the four periods after enrollment, ACT enrollees were more likely to have MPRs ≥.8. In GEE analyses, ACT enrollment was associated with 2.3 greater odds of MPRs ≥.8 (95% confidence interval=1.9-2.7). Among ACT enrollees, higher levels of participation were associated with MPRs ≥.8. CONCLUSIONS In this large, national study, ACT enrollment was associated with higher levels of antipsychotic adherence among VA patients with schizophrenia. This association persisted over time and was greatest among those with higher levels of ACT use.