Rogowski J A, Newhouse J P
RAND Corporation, Washington, DC.
J Health Econ. 1992 Aug;11(2):153-71. doi: 10.1016/0167-6296(92)90032-v.
Medicare's Prospective Payment System pays teaching hospitals using a regression coefficient in a log-log cost function. Previous literature showed that this coefficient is sensitive to the covariates included in the function, but specified teaching intensity as the logarithm of one plus the intern and resident-to-bed ratio. Provided the true relationship is log-log, adding one biases the coefficient substantially but not predicted cost. In a re-specified equation that makes this bias negligible, the coefficient is not nearly as sensitive to the inclusion of other covariates. Because further issues remain to be explored, it is premature to use our results for policy purposes.
医疗保险的预期支付系统使用对数-对数成本函数中的回归系数向教学医院支付费用。以往的文献表明，该系数对函数中包含的协变量敏感，但将教学强度指定为一加实习医生和住院医生与床位比的对数。假设真实关系是对数-对数关系，加一会使系数产生大幅偏差，但不会影响预测成本。在一个重新设定的方程中，这种偏差可以忽略不计，该系数对其他协变量的纳入就不那么敏感了。由于仍有进一步的问题有待探索，将我们的结果用于政策目的还为时过早。
