Composite health plan quality scales

This study employs exploratory factor analysis and scale construction methods with commercial Health Plan Employers Data Information Set (HEDISS) process of care and outcome measures from 1999 to uncover evidence for a unidimensional composite health maintenance organization (HMO) quality scale. Summated scales by categories of care are created and are then used in a factor analysis that has a single factor solution. The category of care scales were used to construct a summated composite scale which exhibits strong evidence of internal consistency (alpha= 0.90). External validity of the composite quality scale was checked by regressing the composite scale on Consumer Assessment of Healthcare Providers and Systems (CAHPS) survey results for 1999.