In Reply Drs Cerasale and Watson raise an interesting point, but certainly the use of observation stays could not have accounted for the entire decline in hospitalizations. The number of hospitalizations averted is much larger than the number of observation stays. Feng et al1 reported that the numbers of observation stays for Medicare fee-for-service beneficiaries were 814 692 in 2007 and 1 019 881 in 2009. Using these numbers as numerators and person-years of Medicare fee-for-service enrollments in 2007 and 2009 reported in our study (Table 1) as denominators, we calculated the rates of observation stays per 100 000 person-years, which were 2961 and 3730 for 2007 and 2009, respectively.
Krumholz HM, Nuti SV, Wang Y. Use of Observation Stays in Calculating Hospitalizations Among Medicare Beneficiaries—Reply. JAMA. 2015;314(24):2691. doi:10.1001/jama.2015.15064