Advancing Risk Adjustment for Schizophrenia. Executive Summary;Final rept. 1 Jul 00-31 Dec 02

摘要

The objective of this study was to develop and validate a series of schizophrenia specific risk adjustment cost models. Methods: Georgia Medicaid claims data linked with institutional inpatient data for 21,602 continuous eligible persons suffering from schizophrenia was used to build a prospective diagnosis-based, a demographic-based, a drug-based, and a combined risk adjustment model. ICD-9-CM and drug category classifications were derived from the literature and supplemented by an expert panel. Variables were screened and cost weights were derived empirically in a random 50% training sample using weighted OLS regression and validated by expert panel review, bootstrapping methods, and assessing indices of discrimination in a 50% validation sample. Results: Measures of discrimination (R(sup 2)) varied between 16.4% for the ICD-9-CM based model to 21.8% for the combined model for trimmed total cost and varied between 4.9% to 11.3% for mental health costs. Risk adjustment models based on drug or ICD-9-CM information performed equally well and the combined models outperformed other models. These models with empirically derived weights can be used to stratify prospective one year total costs or payments and can be used with caution to stratify mental health cost payments.