Differential relationships between continuity of care practices, engagement in continuing care, and abstinence among subgroups of patients with substance use and psychiatric disorders.

Objective: We examined whether patient subgroups with differing substance use disorders (SUDs) and psychiatric severity levels varied on engagement in continuing care and abstinence outcomes, the association of continuity of care practices to engagement, and the association of engagement to abstinence.

Method: Staff in 28 Veterans Affairs SUD treatment programs used the Addiction Severity Index to assess 865 (98% male) patients' alcohol, other drug, and psychiatric problems at treatment entry. At discharge, staff supplied data on patients' treatment, motivation, and continuity of care practices. Administrative data assessed continuing care engagement. Six months after discharge, 673 patients completed a self-reported Addiction Severity Index. The sample comprised four SUD subgroups (abstinent from alcohol and other drugs, used alcohol only, used other drugs only, used alcohol and other drugs) and two psychiatric severity subgroups (high and moderate to low).

Results: Patients receiving more continuity of care services engaged in continuing care longer. This association was weaker for the high psychiatric severity subgroup than for the moderate-to-low psychiatric severity subgroup. Engagement in continuing care was the most important predictor of abstinence overall. The positive association between engagement in continuing care and abstinence was strongest for the SUD subgroup using both alcohol and other drugs. This group had the lowest likelihood of abstinence if they engaged in little or no continuing care but showed the greatest increase in abstinence with longer continuing care engagement.

Conclusions: Subgroups' differential responsiveness to continuity of care services and engagement highlights the crucial importance of continuing care interventions to improve abstinence outcomes for certain subgroups of patients who use both alcohol and other drugs.