An Economic Evaluation of a Proactive Consultation-Liaison Psychiatry Pilot as Compared to Usual Psychiatric Consultation on Demand for Hospital Medicine

Background: A growing literature demonstrates the value of the proactive consultation-liaison psychiatry model for health care systems through reductions in hospital length of stay. Few studies include financial outcomes. Objective: We evaluated the return on investment of a 1-year proactive consultation-liaison psychiatry pilot in a hospital medicine unit. Methods: We used a pre-post method with an active comparison of three hospital medicine units with regular psychiatric consultation on demand. We staffed the pilot unit with one full-time psychiatrist who focused on early case finding, close communication with unit staff, frequent follow-up visits, and proactive discharge planning. We assessed the 1-year change in mean length of stay for all patients receiving psychiatric consultation, from which we estimated the direct contribution margin from bed-backfills and the program's return on investment. Results: On the pilot unit, the percent of discharges that received psychiatric consultation increased from 7.34% to 13.79%, and the length of stay for patients who consulted declined by a mean of 1.82 days (P < 0.05), as compared to an increase of 0.15 days (P > 0.05) on the usual-care units. The pilot unit reduction in length of stay saved 451.71 days in total, allowing for 73.81 bed-backfills, a direct contribution margin of $419,343 (95% confidence interval, $50,754 to $787,933), a net direct contribution margin of $298,245 (-$70,344 to $666,835), and an return on investment of 132% (−31% to 295%). Conclusion: This study strengthens existing evidence for the relative cost-effectiveness of proactive consultation-liaison psychiatry for hospital medicine compared with usual psychiatric consultation on demand.