Excess health care service utilization and costs associated with underrecognition of psychiatric comorbidity in a medical/surgical inpatient setting.

Psychiatric comorbidity is common among chronically medically ill populations and the presence of psychiatric conditions tends to be associated with increased costs and excess utilization of general medical services. The purpose of this pilot investigation was to determine whether differences in nonpsychiatric inpatient hospitalization frequency, duration, and costs existed between patients receiving outpatient psychiatric treatment and patients without identified psychiatric problems. Length of stay and cost information for patients that had at least 1 inpatient medical/surgical hospitalization during a 6-month period was extracted from the hospital's inpatient billing database (n = 10,865). The medical record numbers of these patients were then cross-referenced against the outpatient psychiatry-billing database for the same 6-month period, thereby identifying all patients that had both a nonpsychiatric inpatient hospitalization and an outpatient psychiatry visit (n = 149). Patients identified as having outpatient psychiatry involvement had significantly more nonpsychiatric hospitalizations on average (mean = 1.60) than nonpsychiatric patients (mean = 1.34) during the study period (t4381 = 2.94, P = .003). There was no difference in the total costs associated with these hospitalizations between the 2 groups. Those that had a psychiatry consult during the nonpsychiatric hospitalization had a significantly higher length of stay and costs than those without. Thus, the criteria used to determine whether or not a psychiatry consultation is triggered, and the timing of the consultation request need further study.