Effect of critical access hospital conversion on patient safety.

BACKGROUND The Medicare Rural Hospital Flexibility Program of the 1997 Balanced Budget Act allowed hospitals meeting certain criteria to convert to critical access hospitals (CAH) and changed their Medicare reimbursement mechanism from prospective payment system (PPS) to cost-based. OBJECTIVE To examine the impact of CAH conversion on hospital patient safety. DATA SOURCE Secondary data on hospital patient safety indicators (PSIs), hospital CAH status, patient case-mix, and market variables, for 89 Iowa rural hospitals during 1997-2004. STUDY DESIGN We employed quasi-experimental designs that use both control groups and pretests. The hospital-year was the unit of analysis. We used generalized estimating equations logit and random-effects Tobit models to assess the effects of CAH conversion on hospital patient safety. The models were adjusted for patient case-mix and market variables. Sensitivity analyses, which varied by sample and statistical model, were used to examine the robustness of our findings. DATA EXTRACTION METHODS PSIs were computed from Iowa State Inpatient Databases (SIDs) using Agency for Healthcare Research and Quality indicators software. Hospital CAH status was extracted from Iowa Hospital Association. Patient case-mix variables were extracted from Iowa SIDs. Market variables came from Area Resource File (ARF). PRINCIPAL FINDINGS CAH conversion in Iowa rural hospitals was associated with better performance of risk-adjusted rates of iatrogenic pneumothorax, selected infections due to medical care, accidental puncture or laceration, and composite score of four PSIs, but had no significant impact on the observed rates of death in low-mortality diagnosis-related groups (DRGs), foreign body left during procedure, risk-adjusted rate of decubitus ulcer, or composite score of six PSIs. Conclusion. CAH conversion is associated with enhanced performance of certain PSIs.