Hospital characteristics and the agency for healthcare research and quality inpatient quality indicators: A systematic review

Background: The Agency for Healthcare Research and Quality Inpatient Quality Indicators (IQIs) include inpatient mortality for selected procedures and medical conditions. They have assumed an increasingly prominent role in hospital comparisons. Healthcare delivery and policy-related decisions need to be driven by reliable research that shows associations between hospital characteristics and quality of inpatient care delivered. Objectives: To systematically review the literature on associations between hospital characteristics and IQIs. Methods: We systematically searched PubMed and gray literature (2000-2012) for studies relevant to 14 hospital characteristics and 17 IQIs. We extracted data for study characteristics, IQIs analyzed, and hospital characteristics (e.g., teaching status, bed size, patient volume, rural vs. urban location, and nurse staffing). Results: We included 16 studies, which showed few significant associations. Four hospital characteristics (higher hospital volume, higher nurse staffing, urban vs. rural status, and higher hospital financial resources) had statistically significant associations with lowermortality and selected IQIs in approximately half of the studies. For example, there were no associations between nurse staffing and four IQIs; however, approximately 50% of studies showed a statistically significant relationship between nurse staffing and lower mortality for six IQIs. For two hospital characteristics higher bed size and disproportionate share percentage all statistically significant associations had higher mortality. Five hospital characteristics (teaching status, system affiliation, ownership, minority-serving hospitals, and electronic health record status) had some studies with significantly positive and some with significantly negative associations, and many studies with no association. Conclusions: We found few associations between hospital characteristics and mortality IQIs. Differences in study methodology, coding across hospitals, and hospital case-mix adjustment may partly explain these results. Ongoing research will evaluate potential mechanisms for the identified associations.