Epidemiological assessment of diet: a comparison of a 7-day diary with a food frequency questionnaire using urinary markers of nitrogen, potassium and sodium
Epidemiological assessment of diet: a comparison of a 7-day diary with a food frequency questionnaire using urinary markers of nitrogen, potassium and sodium
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DOI：
10.1093/ije/30.2.309
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发表时间：
2001-04-01
影响因子：
7.7
通讯作者：
Bingham, S
中科院分区：
文献类型：
--
作者：
Day, NE;McKeown, N;Bingham, S
背景为流行病学研究开发的饮食工具的验证研究通常使用某种形式的饮食记录作为比较的标准。最近的工作表明，由于缺乏测量误差的独立性，与饮食记录的比较可能高估了流行病学仪器测量习惯饮食摄入量的能力。因此，估计饮食与疾病相关性的回归稀释程度可能相应地被低估了。使用摄入量的生化措施可能会缓解这一问题。在这篇文章中，我们报告了使用尿氮、钾和钠摄入量的测量来比较半定量食物频率问卷(FFQ)和7天饮食日记(7DD)的表现，以估计这些营养物质在一年中的平均摄入量。这些人还被要求在6-9个月的时间里六次提供24小时尿样，涵盖了创纪录的FFQ和7DD完成的时间。对尿液中的氮、钾和钠进行了检测。该方案由123个人完成。结果：(1)FFQ和7DD的误差方差均是7DD的两倍以上；(2)FFQ和7DD在不同时间完成的误差之间存在显著的相关性(0.46~0.58)；(3)每种营养素的FFQ误差与7DD误差之间存在中等相关(0.24~0.29)；(4)FFQ不同营养素误差之间的相关性(0.77~0.80)高于7DD误差(0.52~0.70)。结论FFQ的回归稀释明显大于7DD，对于所考虑的营养素，也大于单纯基于记录型或日记型仪器进行验证研究所得出的结论。
Background Validation studies of dietary instruments developed for epidemiological studies have typically used some form of diet record as the standard for comparison. Recent work suggests that comparison with diet record may overestimate the ability of the epidemiological instrument to measure habitual dietary intake, due to lack of independence of the measurement errors. The degree of regression dilution in estimating diet-disease association may therefore have been correspondingly underestimated. Use of biochemical measures of intake may mitigate the problem. In this paper, we report on the use of urinary measures of intakes of nitrogen, potassium and sodium to compare the performance of a semiquantitative food frequency questionnaire (FFQ) and a 7-day diet diary (7DD) to estimate average intake of these nutrients over one year.Methods In all, 179 individuals were asked to complete an FFQ and a 7DD on two occasions separated by approximately 12 months. The individuals were also asked to provide 24-hour urine samples on six occasions over a 6-9-month period, covering the time at which the record FFQ and 7DD were completed. The urine was assayed for nitrogen, potassium and sodium. The protocol was completed by 123 individuals. The data from these individuals were analysed to estimate the covariance structure of the measurement errors of the FFQ, the 7DD and a single 24-hour urine measurement, and to estimate the degree of regression dilution associated with the FFQ and 7DD.Results The results demonstrated that: (1) the error variances for each of the three nutrients was more than twice as great with the FFQ than the 7DD; (2) there was substantial correlation (0.46-0.58) between the error of both the FFQ and the 7DD completed on different occasions; (3) there was moderate correlation (0.24-0.29) between the error in the FFQ and the error in the 7DD for each nutrient; (4) the correlation between errors in different nutrients was higher for the FFQ (0.77-0.80) than for the 7DD (0.52-0.70).Conclusions The regression dilution with the FFQ is considerably greater than with the 7DD and also, for the nutrients considered, greater than would be inferred if validation studies were based solely on record or diary type instruments.