Characterizing the relationship between diagnostic intensity and quality of care.

Objectives: The relationship between diagnostic intensity and quality of care has not been well-characterized at the hospital level. We performed an exploratory analysis to better delineate this relationship using a hospital-level diagnostic overuse index and accepted hospital quality metrics (readmissions and mortality).

Methods: We previously developed and published a hospital-level diagnostic overuse index. A hospital's overuse index value (which ranges from 0 to 0.986, with larger numbers indicating more overuse) was our predictor variable of interest. The outcome variables were excess readmission ratios and mortality rates for common medical conditions, which CMS publicly reports. The model controlled for Elixhauser comorbidity score, hospital bed size, hospital teaching status, and random effects that vary by state.

Results: We did not find a statistically significant relationship between our overuse index and the quality measures we evaluated.

Conclusions: The lack of a significant relationship between diagnostic intensity and quality, at least as measured by our overuse index and the tested quality metrics, suggests that well-targeted efforts to reduce diagnostic overuse in hospitals may not adversely impact quality of care.