Department of Psychiatry and Behavioral Science, Stony Brook University, Stony Brook, New York, USA.
Contemp Clin Trials. 2010 Sep;31(5):466-72. doi: 10.1016/j.cct.2010.05.006. Epub 2010 May 23.
Patient reported outcomes (PROs) play an essential role in clinical trials, though questions have been raised about the accuracy of PROs using long recall periods. This paper examines the utility of a PRO employing a single momentary assessment of pain in a sample of community rheumatology patients. We explore the accuracy and reliability of a single assessment versus the average of multiple assessments taken over 1-week, which is considered a common outcome reporting period. A secondary analysis of 128 patients who monitored their pain intensity with momentary data collections several times a day for a week and 3 months later for another week allowed a comparison of randomly-selected single momentary assessments with the average of many assessments from the week. Results from cross-sectional analyses of the first week were that levels of pain measured by single points were not significantly different than the week average in 4 of 5 analyses, but these single-point assessments had much higher variance. Correlations of single-point and week averages were below 0.70. Longitudinal analysis of change scores across 3 months also demonstrated considerable unreliability of single-point measures, thus the statistical power generated by single-point assessments was considerably less than the more reliable week average. Our conclusion is that single momentary assessments, at least for representing an outcome over a period of a week, are not ideal measures. We discuss alternative measurement strategies for efficiently collecting PRO data for a 1-week period using end-of-day diaries or 7-day recall measures.
患者报告的结局（PROs）在临床试验中起着重要作用，但人们对使用长时间回忆期的 PROs 的准确性提出了质疑。本文研究了在社区风湿病患者样本中使用单次疼痛瞬间评估的 PRO 的效用。我们探讨了单次评估与一周内多次评估平均值的准确性和可靠性，后者被认为是常见的结局报告期。对 128 名患者的二次分析，这些患者在一周内每天多次使用瞬时数据收集来监测他们的疼痛强度，3 个月后又进行了一周的监测，从而可以比较随机选择的单次瞬时评估与一周内多次评估的平均值。对第一周进行的横断面分析结果表明，在 5 次分析中的 4 次中，单点测量的疼痛水平与周平均值没有显著差异，但这些单点评估的方差要高得多。单点和周平均值之间的相关性低于 0.70。跨越 3 个月的变化分数的纵向分析也表明单点测量的可靠性较差，因此单点评估产生的统计效力明显小于更可靠的周平均值。我们的结论是，至少对于代表一周内的结局，单次瞬间评估不是理想的测量方法。我们讨论了使用每日结束时日记或 7 天回忆测量来高效收集 PRO 数据的替代测量策略。
