Newhouse Joseph P, Brook Robert H, Duan Naihua, Keeler Emmett B, Leibowitz Arleen, Manning Willard G, Marquis M Susan, Morris Carl N, Phelps Charles E, Rolph John E
Harvard University, Boston, MA, USA.
J Health Polit Policy Law. 2008 Apr;33(2):295-308; discussion 309-17. doi: 10.1215/03616878-2007-061.
In a prior article in this journal, John Nyman argues that the effect on health care use and spending found in the RAND Health Insurance Experiment is an artifact of greater voluntary attrition in the cost-sharing plans relative to the free care plan. Specifically, he speculates that those in the cost-sharing plans, when faced with a hospitalization, withdrew. His argument is implausible because (1) families facing a hospitalization would be worse off financially by withdrawing; (2) a large number of observational studies find a similar effect of cost sharing on use; (3) those who left did not differ in their utilization prior to leaving; (4) if there had been no attrition and cost sharing did not reduce hospitalization rates, each adult in each family that withdrew would have had to have been hospitalized once each year for the duration of time they would otherwise have been in the experiment, an implausibly high rate; (5) there are benign explanations for the higher attrition in the cost-sharing plans. Finally, we obtained follow-up health-status data on the great majority of those who left prematurely. We found the health-status findings were insensitive to the inclusion of the attrition cases.
在本期刊之前的一篇文章中，约翰·尼曼认为，兰德健康保险实验中发现的对医疗保健使用和支出的影响，是成本分担计划相对于免费医疗计划而言更高的自愿退出率所导致的人为结果。具体而言，他推测参与成本分担计划的人在面临住院治疗时会选择退出。他的观点难以置信，原因如下：（1）面临住院治疗的家庭若选择退出，经济状况会更糟；（2）大量观察性研究发现成本分担对使用情况有类似影响；（3）退出的人在退出前的使用情况并无差异；（4）如果没有退出情况且成本分担并未降低住院率，那么每个退出家庭中的每个成年人在原本应参与实验的时间段内，每年都必须住院一次，这一比率高得难以置信；（5）对于成本分担计划中较高的退出率存在合理的解释。最后，我们获得了绝大多数过早退出者的后续健康状况数据。我们发现，健康状况结果对纳入退出案例不敏感。
