If "intensive transition interventions" were applied to those 250 patients, and the interventions were 100% effective, "then you would prevent 18% x 250 or 45 readmissions," reducing the number of readmissions from 223 per 1,000 to 178, "a 4.5% absolute reduction in the readmission rate."
Practically speaking, he added, those interventions would not be 100% effective [it would be] more like 50%. "So it may be more like half that, a 2.3% absolute reduction, i.e. from 22.3% to 20%. But this is still substantial. If we could do this nationally, it would save society about $2 billion."
The team excluded unavoidable readmissions, for example a patient originally treated for heart failure, but who was readmitted because of newly developed conditions not related to known diseases during the index admission. They also excluded planned readmissions, for example a cancer patient's scheduled chemotherapy treatment.
"To our knowledge, no previous studies included the number of procedures performed during the index stay in their models," and hemoglobin level as a way to measure anemia has only been used in one other study, they said.
In particular, Donzé wrote, number of prior hospitalizations and their length of stay of the index admission "were important predictors," because they represent a way to measure a patient's illness severity.
It's unclear how translatable such success in a Boston hospital might be, since Massachusetts health reform laws gave hospitals in that state a head start incentive to reduce readmissions through penalties imposed on Medicaid readmissions too.