Department of Medicine, 5-10 University Terrace, University of Alberta, Edmonton, Alberta, Canada, T6G 2T4.
Public Health Nutr. 2013 Aug;16(8):1445-53. doi: 10.1017/S1368980012003692. Epub 2012 Aug 14.
To assess the validity of a 161-item quantitative FFQ (QFFQ) that was developed to evaluate dietary risk factors for a colorectal adenoma case–control study.
A cross-sectional validation study of the QFFQ against 4 d food diary using Pearson correlation coefficients, cross-classification, weighted k statistics and Bland–Altman plotting.
Two hospitals in Sa˜o Paulo, Brazil.
Ninety-seven healthy Japanese-Brazilian adults (40–75 years) were recruited. One participant was excluded from the analysis due to unusual energy intake report.
Mean daily nutrient intakes from the QFFQ were higher than from the food diary. The mean Pearson correlation coefficient for nutrient intakes between the QFFQ and the average of the 4 d food diary was 0?43, and increased to 0?45 after correcting correlations for attenuation due to residual day-to-day variation in the food diary measurements. Adjustment for total energy and further adjustment for age and gender decreased the correlation; however, 77% of observations remained in the same or adjacent quartiles with a mean weighted k of 0?22. Bland–Altman plots on loge-transformed data showed no linear trend between the differences and means for energy, fat, protein, total folate and vitamin C. Compared with the food diary, the QFFQ showed consistently reasonable performance for dietary fibre, total folate, retinol, riboflavin and vitamin C.
This investigation supports the relative validity of the QFFQ as a method for assessing long-term dietary intake. The instrument will be a useful tool in the analysis of diet–adenoma associations in the case–control study.
评估一种用于评估结直肠腺瘤病例对照研究中饮食危险因素的 161 项定量 FFQ（QFFQ）的有效性。
使用 Pearson 相关系数、交叉分类、加权 k 统计量和 Bland–Altman 绘图对 QFFQ 进行横断面验证研究，以 4 天食物日记为对照。
巴西圣保罗的两家医院。
招募了 97 名健康的日本裔巴西成年人（40-75 岁）。由于能量摄入报告异常，一名参与者被排除在分析之外。
QFFQ 每日营养素摄入量的平均值高于食物日记。QFFQ 与 4 天食物日记平均值之间营养素摄入量的平均 Pearson 相关系数为 0.43，校正食物日记测量的残余日内变异引起的衰减相关性后增加到 0.45。调整总能量以及进一步调整年龄和性别会降低相关性；然而，77%的观察值仍处于相同或相邻四分位区间，平均加权 k 值为 0.22。对对数转换数据的 Bland–Altman 图显示，能量、脂肪、蛋白质、总叶酸和维生素 C 的差异和平均值之间没有线性趋势。与食物日记相比，QFFQ 对膳食纤维、总叶酸、视黄醇、核黄素和维生素 C 的评估具有相对合理的性能。
该研究支持 QFFQ 作为评估长期饮食摄入的方法具有相对有效性。该工具将成为病例对照研究中饮食-腺瘤关联分析的有用工具。
