Did Hospital Readmissions Fall Because Per Capita Admission Rates Fell?

Recent reductions in readmission rates have been attributed to public reporting and pay-for-performance initiatives focused on readmissions. However, admission rates also declined during the same period. We demonstrate that, because the probability of an admission occurring soon after another is lower when there are fewer admissions per patient, the reduction in admission rates may have explained much of the reduction in readmission rates.