Better metrics needed to determine quality

There has been an intense focus on reducing unplanned readmissions in hospitals. Payers are refusing to pay for them, and increasingly the public believes that they are a determinant of the level of quality of care a particular facility provides to patients. But a study in the June issue of Health Affairs1 indicates that looking at this single data point doesn't tell the whole quality story.

The authors looked at readmission rates for hospitals at two points — 2009 and 2011 — to assess change, as well as other measures commonly associated with quality: mortality rates, rates of process measure adherence for conditions like heart attacks and pneumonia, and patient volume. The additional measures came from data collected through Hospital Compare and the American Hospital Association.

The correlation between quality indicators and readmission rates turned out to be "weak or inverse," the authors found. "There were no significant differences in mean readmission rates across all quartiles of mortality rates for heart attack and pneumonia," the study notes. "For heart failure, mean readmission rates were significantly higher for the hospitals in the lowest mortality quartile. Results comparing the change in readmission and mortality rates longitudinally, which controls for time-invariant hospital confounders, showed a weak correlation between the two outcomes for all three conditions."

One possible explanation is that hospitals with low mortality rates have more patients who can be readmitted, and those with high rates have fewer. But the authors note there is not any correlation between readmission rates and other quality indicators, either. It could also be that transitions of care to sectors outside the hospital setting could influence readmission rates, while the quality measures the authors chose are all the purview of hospitals.

Regardless, the notion that you can determine quality by looking at this single 30-day period for an unplanned readmission seems inadequate.

Reference

1. Press MJ, Scanlon DP, Ryan AM et al. Limits Of Readmission Rates In Measuring Hospital Quality Suggest The Need For Added Metrics. Health Aff June 2013 vol. 32 no. 6 1083-1091.