Gersovitz M, Madden J P, Smiciklas-Wright H
J Am Diet Assoc. 1978 Jul;73(1):48-55.
The internal validity of a 24-hr. dietary recall and a seven-day dietary record was investigated among a group of non-institutionalized elderly subjects who were participating in a congregate meals program. Internal validity was assessed by comparing reported intake with unobtrusively obtained data on actual intake. Validity results suggest that the recall is prone to over-reporting low intakes and under-reporting high intakes. This pattern has been referred to as the "flat-slope syndrome." Records collected during the first few dyas were less prone to this syndrome; however, validity declined by the fifth, sixth, and seventh record days. Also, as the record progressed to the seventh day, the demographic nature of the sample became biased due to drop-outs and decreased usability of the records.
在一组参与集体用餐计划的非机构化老年受试者中，对24小时饮食回顾法和七天饮食记录法的内部效度进行了调查。通过将报告摄入量与通过不显眼方式获取的实际摄入量数据进行比较来评估内部效度。效度结果表明，饮食回顾法容易高估低摄入量并低估高摄入量。这种模式被称为“平缓斜率综合征”。在最初几天收集的记录较少出现这种综合征；然而，到第五、第六和第七天记录时，效度下降。此外，随着记录持续到第七天，由于退出和记录可用性降低，样本的人口统计学特征出现偏差。
