Department of Nutrition and Food Sciences, University of Rhode Island, Kingston, RI02881, USA.
Department of Medicine, Division of General Internal Medicine, Massachusetts General Hospital, Boston, MA02114, USA.
Br J Nutr. 2021 Sep 28;126(6):933-941. doi: 10.1017/S0007114520004833. Epub 2020 Dec 3.
The Grocery Purchase Quality Index (GPQI) reflects concordance between household grocery purchases and US dietary recommendations. However, it is unclear whether GPQI scores calculated from partial purchasing records reflect individual-level diet quality. This secondary analysis of a 9-month randomised controlled trial examined concordance between the GPQI (range 0-75, scaled to 100) calculated from 3 months of loyalty-card linked partial (≥50 %) household grocery purchasing data and individual-level Healthy Eating Index (HEI) scores at baseline and 3 months calculated from FFQ (n 209). Concordance was assessed with overall and demographic-stratified partially adjusted correlations; covariate-adjusted percentage score differences, cross-classification and weighted κ coefficients assessed concordance across GPQI tertiles (T). Participants were middle aged (55·4 (13·9) years), female (90·3 %), from non-smoking households (96·4 %) and without children (70·7 %). Mean GPQI (54·8 (9·1) %) scores were lower than HEI scores (baseline: 73·2 (9·1) %, 3 months: 72·4 (9·4) %) and moderately correlated (baseline r 0·41 v. 3 months r 0·31, P < 0·001). Correlations were stronger among participants with ≤ bachelor's degree, obesity and children. Scores showed moderate agreement (κ = 0·25); concordance was highest in T3. Participants with high (T3) v. low (T1) GPQI scores had 7·3-10·6 higher odds of having HEI scores >80 % at both time points. Household-level GPQI was moderately correlated with self-reported intake, indicating their promise for evaluating diet quality. Partial purchasing data appear to moderately reflect individual diet quality and may be useful in interventions monitoring changes in diet quality.
食品购买质量指数（GPQI）反映了家庭食品购买与美国膳食建议的一致性。然而，目前尚不清楚从部分购买记录计算得出的 GPQI 分数是否反映了个体的饮食质量。这项为期 9 个月的随机对照试验的二次分析，检验了从 3 个月的会员卡链接的部分（≥50%）家庭食品购买数据计算得出的 GPQI（范围 0-75，标准化为 100）与基线和 3 个月时的个人水平健康饮食指数（HEI）分数之间的一致性，这些分数是通过 FFQ（n=209）计算得出的。使用整体和按人口统计学分层部分调整后的相关性；协变量调整后的百分比评分差异、交叉分类和加权κ系数评估了 GPQI 三分位数（T）之间的一致性。参与者的年龄中位数为 55.4（13.9）岁，女性占 90.3%，来自不吸烟家庭（96.4%）且没有孩子（70.7%）。平均 GPQI（54.8（9.1）%）分数低于 HEI 分数（基线：73.2（9.1）%，3 个月：72.4（9.4）%），且中度相关（基线 r=0.41，3 个月 r=0.31，P＜0.001）。在具有≤学士学位、肥胖和儿童的参与者中，相关性更强。评分显示出中度一致性（κ=0.25）；T3 中的一致性最高。在两个时间点，GPQI 得分高（T3）的参与者比得分低（T1）的参与者更有可能 HEI 得分＞80%，优势比为 7.3-10.6。家庭层面的 GPQI 与自我报告的摄入量中度相关，表明它们在评估饮食质量方面具有潜力。部分购买数据似乎中度反映了个体的饮食质量，并且可能在监测饮食质量变化的干预措施中有用。
