To the Editor: Dr Vaughan-Sarrazin and colleagues1 found that states with continuous certificate of
need (CON) regulations had higher hospital volume and lower mortality rates
for coronary artery bypass graft (CABG) surgery.
However, the Medicare Provider Analysis and Review (MedPAR) files that
the authors used do not include data for patients enrolled in Medicare Part
C, which covers almost all Medicare managed care patients. Population-weighted
Medicare managed care penetration rates2 differ
considerably by CON status: in December 1999 the penetration rates were 26.4%
for states with no CON regulations, 17.6% for those with continuous CON regulations,
and 16.9% for those with intermittent CON regulations. Thus, the data may
be missing information for as many as 25% of patients undergoing CABG surgery
in states without CON. Therefore, the results of Vaughan-Sarrazin et al probably
overstate the difference in average volume between states with and without
CON regulations. Moreover, the reported mortality differentials between regulated
and unregulated states do not include managed care patients.
Ho V. Certificate of Need Regulations and Hospital Mortality. JAMA. 2003;289(5):551. doi:10.1001/jama.289.5.551-a