SELECTION BIAS IN AN INPATIENT OUTCOMES MONITORING PROJECT

Managed care organizations increasingly tout clinical outcomes assessm ent as the mechanism by which we will ensure quality and compare provi ders. The authors report on their experience with a multisite inpatien t outcomes monitoring project by comparing patients who accepted (N = 51), refused (N = 36), or were not asked (N = 110) to participate in t he project. The patients who were asked to participate had significant ly longer inpatient stays compared with the unasked group (11.2 vs 6.9 days). Patients who agreed to participate in the project were more li kely to have a bipolar (43.1% vs 19.2%) or any affective disorder (94. 1% vs 79.5%), and less likely to have a schizophrenic disorder (2.0% v s 11.6%) than the refused and unasked groups. The project participants also had higher 90-day readmit rates (27.5% vs 9.6%), more readmissio ns (0.51 vs 0.16), and more education (14.59 vs 13.51 years) than nonp articipating patients. In this preliminary study, patient-related vari ables were found to influence who the staff asked and who consented to participate in this clinical outcomes monitoring project. The authors distinguish clinical outcomes monitoring from treatment effectiveness research and discuss the need to develop methodologies that deal with nonrepresentative patient sampling and intersite variability in recru itment practices. (C) 1997 Elsevier Science Inc.