Ware J E, Kosinski M
Quality Metric, Inc, Lincoln, RI 02865, USA.
Qual Life Res. 2001;10(5):405-13; discussion 415-20. doi: 10.1023/a:1012588218728.
In response to questions raised about the "accuracy" of SF-36 physical (PCS) and mental (MCS) component summary scores, particularly extremely high and low scores, we briefly comment on: how they were developed, how they are scored, the factor content of the eight SF-36 subscales, cross-tabulations between item-level responses and extreme summary scores, and published and new tests of their empirical validity. Published cross-tabulations between SF-36 items and PCS and MCS scores, reanalyses of public datasets (N = 5919), and preliminary results from the Medicare Health Outcomes Survey (HOS) (N = 172,314) yielded little or no evidence in support of Taft's hypothesis that extreme scores are an invalid artifact of some negative scoring weights. For example, in the HOS, those (N = 432) with "unexpected" PCS scores worse than 20 (which, according to Taft, indicate better mental health rather than worse physical health) were about 25% more likely to die within two years, in comparison with those scoring in the next highest (21-30) category. In this test and in all other empirical tests, results of predictions supported the validity of extreme PCS and MCS scores. We recommend against the interpretation of average differences smaller than one point in studies that seek to detect "false" measurement and we again repeat our 7-year-old recommendation that results based on summary measures should be thoroughly compared with the SF-36 profile before drawing conclusions. To facilitate such comparisons, scoring utilities and user-friendly graphs for SF-36 profiles and physical and mental summary scores (both orthogonal and oblique scoring algorithms) have been made available on the Internet at www.sf-36.com/test.
针对有关SF-36身体（PCS）和心理（MCS）分量表总分“准确性”的问题，尤其是极高和极低分数的问题，我们简要评论以下方面：它们是如何开发的、如何计分、SF-36八个分量表的因子内容、项目水平反应与极端总分之间的交叉表，以及它们实证效度的已发表和新的检验。已发表的SF-36项目与PCS和MCS分数之间的交叉表、公共数据集（N = 5919）的重新分析，以及医疗保险健康结果调查（HOS）（N = 172,314）的初步结果几乎没有或根本没有证据支持塔夫脱的假设，即极端分数是某些负计分权重的无效产物。例如，在HOS中，那些（N = 432）PCS分数“意外”低于20分（根据塔夫脱的说法，这表明心理健康状况较好而非身体健康状况较差）的人在两年内死亡的可能性比下一个最高分数区间（21 - 30）的人高出约25%。在这个检验以及所有其他实证检验中，预测结果支持极端PCS和MCS分数的有效性。我们建议在试图检测“虚假”测量的研究中，不要对小于一分的平均差异进行解读，并且我们再次重申我们七年前的建议，即在得出结论之前，基于汇总测量结果应与SF-36剖面图进行全面比较。为便于进行此类比较，SF-36剖面图以及身体和心理总分（正交和斜交计分算法）的计分实用工具和用户友好型图表可在互联网上的www.sf-36.com/test获取。
