HOSPITAL-RELATED AND PATIENT-RELATED CHARACTERISTICS DETERMINING MATERNITY LENGTH OF STAY - A HIERARCHICAL LINEAR-MODEL APPROACH

Objectives. The purpose of this study was to identify factors related to pregnancy and childbirth that might be predictive of a patient's le ngth of stay after delivery and to model variations in length of stay. Methods. California hospital discharge data on maternity patients (n = 499 912) were analyzed. Hierarchical linear modeling was used to adj ust for patient case mix and hospital characteristics and to account f or the dependence of outcome variables within hospitals. Results. Subs tantial variation in length of stay among patients was observed. The v ariation was mainly attributed to delivery type (vaginal or cesarean s ection), the patient's clinical risk factors, and severity of complica tions (if any). Furthermore, hospitals differed significantly in mater nity lengths of stay even after adjustment for patient case mix. Concl usions. Developing risk-adjusted models for length of stay is a comple x process but is essential for understanding variation. The hierarchic al linear model approach described here represents a more efficient an d appropriate way of studying interhospital variations than the tradit ional regression approach.