Health Inequalities Research Programme, School of Medicine and Health Sciences, University of Otago, 23 Mein St, Newtown, Wellington, New Zealand.
Soc Sci Med. 2012 Apr;74(7):1117-24. doi: 10.1016/j.socscimed.2011.11.038. Epub 2012 Feb 2.
Self-rated health (SRH) is commonly used in longitudinal analyses as a repeated outcome measure. This assumes that computed changes in SRH over time truly represent within-individual changes in underlying health. The longitudinal validity of SRH, however, is threatened by ceiling effects (where people reporting the highest level of SRH cannot report subsequent improved health), insensitivity to small changes within SRH categories, reference group effects (where individuals assess their health changes relative to their peers) and stability in SRH even when change in underlying health is occurring. We assessed the longitudinal validity of SRH by comparing computed changes in SRH with a measure of self-assessed change in health (SACH). We used two waves of data (2003-2005) from the New Zealand longitudinal Survey of Family, Income and Employment (SoFIE). Computed change in SRH and SACH were compared directly and also in regression models using an objective measure of health outcome change (hospitalisations within the past year). Computed change in SRH and SACH were not well correlated, consistent with ceiling and/or categorisation effects in SRH. In regression models, SACH was more strongly predictive of hospitalisation than computed change in SRH (worse SACH was associated with an increased odds of hospitalisation of 3.7 compared to 1.8 for decreased computed change in SRH). SACH may be affected by recall bias, but if SRH is used as a repeated outcome measure in longitudinal analyses, results may also be biased, if change in SRH does not occur in response to significant health events.
自评健康 (SRH) 通常被用作纵向分析中的重复结果测量指标。这是基于一个假设，即随着时间的推移，SRH 的计算变化真正代表了个体内在健康状况的变化。然而，SRH 的纵向有效性受到上限效应（即报告最高 SRH 水平的人无法报告随后的健康改善）、对 SRH 类别内的微小变化不敏感、参考群体效应（即个体相对于同龄人评估自己的健康变化）以及即使潜在健康发生变化，SRH 也保持稳定的威胁。我们通过将 SRH 的计算变化与自我评估的健康变化测量（SACH）进行比较来评估 SRH 的纵向有效性。我们使用来自新西兰家庭、收入和就业纵向调查（SoFIE）的两个数据波次（2003-2005 年）。直接比较 SRH 和 SACH 的计算变化，并在使用客观健康结果变化测量（过去一年住院）的回归模型中进行比较。SRH 和 SACH 的计算变化相关性不佳，这与 SRH 的上限和/或分类效应一致。在回归模型中，SACH 比 SRH 的计算变化更能预测住院（更差的 SACH 与住院的几率增加 3.7 倍相关，而 SRH 计算变化减少则与住院的几率增加 1.8 倍相关）。SACH 可能受到回忆偏差的影响，但如果 SRH 在纵向分析中被用作重复结果测量指标，如果 SRH 没有对重大健康事件做出反应而发生变化，那么结果也可能存在偏差。
