Agency for Healthcare Research & Quality, 540 Gaither Rd, Rockville, MD 20850, USA.
Health Serv Res. 2011 Feb;46(1 Pt 1):105-19. doi: 10.1111/j.1475-6773.2010.01189.x. Epub 2010 Oct 28.
To determine whether the case mix index (CMI) based on the 53-Resource Utilization Groups (RUGs) captures all the cross-sectional variation in nursing home (NH) costs or whether NHs that have a higher percent of Medicare skilled care days (%SKILLED) have additional costs. DATA AND SAMPLE: Nine hundred and eighty-eight NHs in California in 2005. Data are from Medicaid cost reports, the Minimum Data Set, and the Economic Census.
We estimate hybrid cost functions, which include in addition to outputs, case mix, ownership, wages, and %SKILLED. Two-stage least-square (2SLS) analysis was used to deal with the potential endogeneity of %SKILLED and CMI.
On average 11 percent of NHs days were due to skilled care. Based on the 2SLS model, %SKILLED is associated with costs even when controlling for CMI. The marginal cost of a one percentage point increase in %SKILLED is estimated at U.S.$70,474 or about 1.2 percent of annual costs for the average cost facility. Subanalyses show that the increase in costs is mainly due to additional expenses for nontherapy ancillaries and rehabilitation.
The 53-RUGs case mix does not account completely for all the variation in actual costs of care for postacute patients in NHs.
确定基于 53 项资源利用组（RUGs）的病例组合指数（CMI）是否可以捕捉到所有养老院（NH）成本的横断面变化，或者是否 NH 中 Medicare 熟练护理天数（%SKILLED）的比例较高是否会产生额外成本。
加利福尼亚州 2005 年的 988 家 NH。数据来自医疗补助费用报告、最低数据集和经济普查。
我们估计了混合成本函数，除了输出、病例组合、所有权、工资和%SKILLED 外，还包括了这些因素。使用两阶段最小二乘法（2SLS）分析来解决%SKILLED 和 CMI 的潜在内生性问题。
平均有 11%的 NH 天是由于熟练护理。根据 2SLS 模型，即使在控制了 CMI 的情况下，%SKILLED 仍与成本相关。%SKILLED 增加一个百分点，估计会增加 70474 美元的成本，约占平均成本设施年成本的 1.2%。子分析表明，成本增加主要是由于非治疗性辅助和康复的额外费用。
53-RUGs 病例组合并不能完全解释 NH 中急性后期患者护理实际成本的所有变化。
