Cost-effectiveness of psychotherapy for cluster C personality disorders: a decision-analytic model in the Netherlands.

OBJECTIVE To conduct a formal economic evaluation of various dosages of psychotherapy for patients with avoidant, dependent, and obsessive-compulsive (ie, cluster C) personality disorders (Structured Interview for DSM-IV Personality criteria). METHOD We developed a decision-analytic model to assess the cost-effectiveness of 5 dosages of psychotherapy (ie, long-term outpatient psychotherapy, short-term and long-term day hospital psychotherapy, and short-term and long-term inpatient psychotherapy) over a 5-year time horizon in terms of cost per recovered patient-year and cost per quality-adjusted life-year (QALY). Model parameters were estimated using data from 466 patients with cluster C personality disorders who were admitted to 6 specialist centers of psychotherapy in The Netherlands and assigned to 1 of the 5 treatment groups. Probabilistic analysis was conducted to explore the stability of results over uncertain data ranges. Analyses were conducted from both societal and payer perspectives. RESULTS From the societal perspective and below a threshold of € 2,637 (US $3,351.92) per recovered patient-year, short-term day hospital psychotherapy resulted in the highest level of benefit for its cost; above the threshold, short-term inpatient psychotherapy was the most cost-effective choice. In terms of cost per QALY, this switch point was at a threshold value of € 16,570 (US $21,062.29) per QALY. From the payer perspective, the optimal strategy changed from short-term day hospital psychotherapy to short-term inpatient psychotherapy at threshold values of € 9,874 (US $12,550.94) per recovered patient-year and € 66,302 (US $84,277.13) per QALY. CONCLUSIONS This study indicates that short-term day hospital psychotherapy and short-term inpatient psychotherapy are the most cost-effective treatment strategies for patients with cluster C personality disorders. The ultimate selection depends on what cost-effectiveness threshold is considered acceptable and what perspective is adopted.