RESUMEN
OBJECTIVE: It is often claimed that hospitals that are leaders in biomedical research provide higher health care quality, or vice versa. Although several studies have shown a relationship between teaching status and quality of care, none has analysed the association between research output and hospital outcomes. Our aim was to determine whether there is a relationship between bibliometric measures of research output in acute hospitals and hospital mortality for two common cardiac conditions. METHODS: A cross-sectional analysis of secondary data of in-hospital risk-adjusted mortality for congestive heart failure and acute myocardial infarction (2002-2004) and several bibliometric measures of publications (1996-2004) in cardiovascular disease. The setting was 50 acute Spanish public hospitals, voluntarily participating in an external quality initiative, with more than 30 medical cases of congestive heart failure and acute myocardial infarction per year, and more than five citable papers in the field of heart disease. Spearman's rho non-parametric correlation coefficient was used to assess association. RESULTS: There was a low-to-moderate negative correlation between the risk-adjusted mortality ratio and the weighted citations ratio: -0.43 (95% CI -0.17 to -0.63) for congestive heart failure and -0.37 (-0.10 to -0.59) for acute myocardial infarction. Teaching status and the technological level of the hospital had a stronger correlation with hospital mortality. CONCLUSIONS: Measures of research output could be considered for incorporation into comparisons of the quality of hospitals. A weighted citations ratio is the most suitable measure of research output, but more research is needed on the interplay between research and practice as complementary ways of developing medical knowledge.