Hebert J R, Clemow L, Pbert L, Ockene I S, Ockene J K
Division of Preventive and Behavioral Medicine, University of Massachusetts Medical School, Worcester 01655, USA.
Int J Epidemiol. 1995 Apr;24(2):389-98. doi: 10.1093/ije/24.2.389.
Self-report of dietary intake could be biased by social desirability or social approval thus affecting risk estimates in epidemiological studies. These constructs produce response set biases, which are evident when testing in domains characterized by easily recognizable correct or desirable responses. Given the social and psychological value ascribed to diet, assessment methodologies used most commonly in epidemiological studies are particularly vulnerable to these biases.
Social desirability and social approval biases were tested by comparing nutrient scores derived from multiple 24-hour diet recalls (24HR) on seven randomly assigned days with those from two 7-day diet recalls (7DDR) (similar in some respects to commonly used food frequency questionnaires), one administered at the beginning of the test period (pre) and one at the end (post). Statistical analysis included correlation and multiple linear regression.
Cross-sectionally, no relationships between social approval score and the nutritional variables existed. Social desirability score was negatively correlated with most nutritional variables. In linear regression analysis, social desirability score produced a large downward bias in nutrient estimation in the 7DDR relative to the 24HR. For total energy, this bias equalled about 50 kcal/point on the social desirability scale or about 450 kcal over its interquartile range. The bias was approximately twice as large for women as for men and only about half as large in the post measures. Individuals having the highest 24HR-derived fat and total energy intake scores had the largest downward bias due to social desirability.
We observed a large downward bias in reporting food intake related to social desirability score. These results are consistent with the theoretical constructs on which the hypothesis is based. The effect of social desirability bias is discussed in terms of its influence on epidemiological estimates of effect. Suggestions are made for future work aimed at improving dietary assessment methodologies and adjusting risk estimates for this bias.
饮食摄入量的自我报告可能会受到社会期望或社会认可的影响，从而影响流行病学研究中的风险估计。这些因素会产生反应定势偏差，在以易于识别的正确或期望反应为特征的领域进行测试时，这种偏差很明显。鉴于饮食所具有的社会和心理价值，流行病学研究中最常用的评估方法特别容易受到这些偏差的影响。
通过比较在七个随机分配的日子里多次24小时饮食回顾（24HR）得出的营养得分与两次7天饮食回顾（7DDR）（在某些方面类似于常用的食物频率问卷）得出的营养得分，来测试社会期望和社会认可偏差，其中一次7DDR在测试期开始时（前期）进行，另一次在结束时（后期）进行。统计分析包括相关性分析和多元线性回归分析。
从横断面来看，社会认可得分与营养变量之间不存在相关性。社会期望得分与大多数营养变量呈负相关。在线性回归分析中，相对于24HR，社会期望得分在7DDR的营养估计中产生了较大的向下偏差。对于总能量，这种偏差在社会期望量表上约为每分50千卡，或在其四分位间距内约为450千卡。女性的偏差约为男性的两倍，后期测量中的偏差仅为男性的一半左右。24HR得出的脂肪和总能量摄入得分最高的个体，由于社会期望而产生的向下偏差最大。
我们观察到在报告与社会期望得分相关的食物摄入量时存在较大的向下偏差。这些结果与该假设所基于的理论构想一致。从社会期望偏差对效应的流行病学估计的影响方面讨论了其作用。针对未来旨在改进饮食评估方法并针对这种偏差调整风险估计的工作提出了建议。
