This study examined the technical efficiency determinants of each Organisation for Economic Co-operation and Development (OECD) country's behavioral health system (BHS).

The technical efficiency of each OECD country's BHS was analyzed through data envelopment analysis with model combinations ranging from 1–11 models, with each model constructed with different BHS input and output variable combinations. A decision tree was generated from the efficiency scores of the model with the highest mean technical efficiency score as a predictor variable. Data was obtained from 2013 OECD and Eurostat statistics.

Different model combinations indicated that the model with the highest mean technical efficiency score (.9214) for OECD countries included (i) input variables for smoking, alcohol consumption, daily fruit consumption, the number of psychiatrists, the percentage of live births of young mothers first children, and the time devoted to leisure and personal care and (ii) output variables for death rate by mental and behavioral disorders, diabetes hospital admissions in adults, and suicide rates. Among all model combinations, >45 percent of OECD countries have an efficient BHS. The decision tree graph shows that daily fruit consumption, smoking, and suicide rates are predictor variables of the technical efficiency of an OECD country's BHS.

The study results offer important insights regarding the development of BHS in OECD countries. Health policymakers must develop collaborative activities and implement comprehensive policies promoting internationally-oriented BHS in order to improve the health status of people worldwide and reduce health inequality.