Treatment Duration With Long-Acting Injectable Antipsychotics After In-hospital Initiation: A Retrospective Cohort Study.

Purpose: Long-acting injectable (LAI) antipsychotics are recommended especially for patients with multiple admissions and poor adherence. The empirical basis of this strategy is a matter of debate.

Methods: In a retrospective cohort study extending over 6 years, all patients admitted for inpatient treatment with a diagnosis of psychotic disorders according to International Statistical Classification of Diseases and Related Health Problems, 10th Revision (F2) were screened for treatment episodes with a new start of an LAI. Indication for LAI treatment was based primarily on previous medication default. All-cause discontinuation was used as a measure of treatment efficiency. Patients with early dropout (termination of LAI treatment within 6 months) were compared with patients with longer treatment (treatment >6 months) for sociodemographic and treatment variables using bivariate and multivariate analyses.

Results: A total of 194 treatment episodes with new start of LAIs were identified. Almost one half dropped out within 6 months (early dropout: n = 95 [49%]; mean duration, 2.2 months). Termination of treatment was mainly due to patients' refusal to continue. However, almost a third of patients (61; 31.4%) had a treatment duration of more than 2 years. In a multivariate Cox regression model, longer treatment duration was associated with older age (P = 0.05), not being single (P = 0.04), fewer admissions during the year preceding the index episode (P = 0.02), and better ratings for adherence at the index episode (P = 0.03).

Conclusions: There are both more patients than expected leaving the treatment early and more patients than expected staying for long periods, even among patients with a history of poor adherence.