Shaughnessy P W, Schlenker R E, Hittle D F
Department of Medicine, School of Medicine, University of Colorado Health Sciences Center, Denver 80222, USA.
Health Serv Res. 1995 Apr;30(1):79-113.
We compare case mix of Medicare home health patients under HMO and FFS payment.
A pseudo-experimental design was employed to study case mix using three types of Medicare-certified home health agencies (HHAs): HMO-owned agencies, pure FFS agencies that admit few Medicare HMO patients (less than 5 percent of admissions are Medicare HMO patients), and mixed (or contractual) agencies that admit at least 15 Medicare FFS patients and 15 Medicare HMO patients per month. SAMPLES OF PROVIDERS AND PATIENTS: Random samples of Medicare-aged patients (> or = 65 years) were selected at admission between June 1989 and November 1991 from the 38 study HHAs. Sample sizes by agency type were: 308 patients from 9 HMO-owned agencies; 529 patients from 15 pure FFS agencies; and 381 HMO patients and 414 FFS patients from 14 contractual agencies.
Primary longitudinal data were prospectively collected at admission for all patients on health status indicators, demographics, admission source, and home environment.
The most important case-mix measures were functional and physiologic indicators of health status, including (instrumental) activities of daily living ([I]ADLs). Selected indicators of demographic variables, prior location, living situation, characteristics of informal caregivers, mental/behavioral factors, and resource needs were also used.
(a) The case mix of Medicare FFS patients compared with Medicare HMO patients was more intense in terms of impairments in ADLs, IADLs, and various physiologic conditions. Pressure ulcers as well as neurological and orthopedic impairments requiring rehabilitation care were also more prevalent among FFS patients. (b) Relative to HMO patients admitted to contractual agencies, HMO patients admitted to HMO-owned agencies were moderately more dependent in ADLs and IADLs. However, only 62 percent of HMO patients admitted to HMO-owned agencies, in contrast to 77 percent of HMO patients admitted to contractual agencies, had been hospitalized during the 30 days prior to home health admission. (c) In all, the case mix of patients receiving care from HMO-owned agencies is more heterogeneous than the case mix of HMO patients receiving care from contractual agencies.
The case-mix (and selected utilization) findings indicate that HMOs use home health care differently than does the FFS sector. The greater diversity of case mix for HMO-owned agencies and the narrower or less diverse case mix that characterizes HMO patients receiving home care on a contractual basis point to the likelihood of cost differences among the two types of HMO patients and FFS patients, and raise the question of possible outcome differences.
我们比较健康维护组织（HMO）和按服务项目付费（FFS）支付方式下医疗保险家庭健康患者的病例组合情况。
采用准实验设计，通过三种经医疗保险认证的家庭健康机构（HHA）来研究病例组合情况：HMO所属机构、接纳很少医疗保险HMO患者（入院患者中医疗保险HMO患者占比不到5%）的纯FFS机构，以及每月接纳至少15名医疗保险FFS患者和15名医疗保险HMO患者的混合（或合同制）机构。
1989年6月至1991年11月期间，从38家参与研究的HHA中选取了医疗保险覆盖年龄（≥65岁）患者的随机样本。按机构类型划分的样本量分别为：来自9家HMO所属机构的308名患者；来自15家纯FFS机构的529名患者；以及来自14家合同制机构的381名HMO患者和414名FFS患者。
前瞻性地收集了所有患者入院时关于健康状况指标、人口统计学信息、入院来源和家庭环境的主要纵向数据。
最重要的病例组合测量指标是健康状况的功能和生理指标，包括（工具性）日常生活活动（[I]ADL）。还使用了人口统计学变量、先前所在地点、生活状况、非正式照料者特征、心理/行为因素以及资源需求的选定指标。
（a）与医疗保险HMO患者相比，医疗保险FFS患者在ADL、IADL和各种生理状况的损伤方面病例组合更为严重。压疮以及需要康复护理的神经和骨科损伤在FFS患者中也更为普遍。（b）相对于入住合同制机构的HMO患者，入住HMO所属机构的HMO患者在ADL和IADL方面的依赖性略高。然而，入住HMO所属机构的HMO患者中只有62%在家庭健康入院前30天内住过院，相比之下，入住合同制机构的HMO患者这一比例为77%。（c）总体而言，接受HMO所属机构护理的患者的病例组合比接受合同制机构护理的HMO患者的病例组合更加多样化。
病例组合（以及选定的利用率）研究结果表明，HMO使用家庭健康护理的方式与FFS部门不同。HMO所属机构病例组合的多样性更大，而通过合同制接受家庭护理的HMO患者的病例组合更窄或多样性更低，这表明两类HMO患者和FFS患者之间可能存在成本差异，并引发了可能存在结果差异的问题。
