To accurately examine associations of physical activity (PA) with disease outcomes, a valid method of assessing free-living activity is required. We examined the validity of a brief PA questionnaire (PAQ) used in the European Prospective Investigation into Cancer and Nutrition (EPIC). PA energy expenditure (PAEE) and time spent in moderate and vigorous physical activity (MVPA) was measured in 1,941 healthy individuals from 10 European countries using individually-calibrated combined heart-rate and movement sensing. Participants also completed the short EPIC-PAQ, which refers to past year's activity. Pearson (r) and Spearman (σ) correlation coefficients were calculated for each country, and random effects meta-analysis was used to calculate the combined correlation across countries to estimate the validity of two previously- and one newly-derived ordered, categorical PA indices ("Cambridge index", "total PA index", and "recreational index") that categorized individuals as inactive, moderately inactive, moderately active, or active. The strongest associations with PAEE and MVPA were observed for the Cambridge index (r = 0.33 and r = 0.25, respectively). No significant heterogeneity by country was observed for this index (I(2) = 36.3%, P = 0.12; I(2) = 0.0%, P = 0.85), whereas heterogeneity was suggested for other indices (I(2) > 48%, P < 0.05, I(2) > 47%, P < 0.05). PAEE increased linearly across self-reported PA categories (P for trend <0.001), with an average difference of approximately 460 kJ/d for men and 365 kJ/d for women, between categories of the Cambridge index. The EPIC-PAQ is suitable for categorizing European men and women into four distinct categories of overall physical activity. The difference in PAEE between categories may be useful when estimating effect sizes from observational research.

中文翻译：

---

在 10 个欧洲国家评估身体活动的简短问卷的有效性。

为了准确检查身体活动 (PA) 与疾病结果的关联，需要一种评估自由生活活动的有效方法。我们检查了欧洲癌症和营养前瞻性调查 (EPIC) 中使用的简短 PA 问卷 (PAQ) 的有效性。来自 10 个欧洲国家的 1,941 名健康人使用单独校准的心率和运动感应相结合，测量了 PA 能量消耗 (PAEE) 和中度和剧烈体育活动 (MVPA) 的时间。参与者还完成了简短的 EPIC-PAQ，它涉及去年的活动。计算每个国家的 Pearson (r) 和 Spearman (σ) 相关系数，随机效应荟萃分析用于计算各国的综合相关性，以估计两个先前和一个新派生的有序分类 PA 指数（“剑桥指数”、“总 PA 指数”和“休闲指数”）的有效性) 将个人分类为不活跃、中度不活跃、中度活跃或活跃。在剑桥指数中观察到与 PAEE 和 MVPA 的最强关联（分别为 r = 0.33 和 r = 0.25）。没有观察到该指数的国家间显着异质性（I(2) = 36.3%，P = 0.12；I(2) = 0.0%，P = 0.85），而建议其他指数存在异质性（I(2) > 48 %，P < 0.05，I(2) > 47%，P < 0.05)。PAEE 在自我报告的 PA 类别中呈线性增加（趋势 P <0.001），在剑桥指数的不同类别之间，男性的平均差异约为 460 kJ/d，女性的平均差异约为 365 kJ/d。EPIC-PAQ 适用于将欧洲男性和女性分为四个不同的整体体育活动类别。在通过观察性研究估计效果大小时，类别之间的 PAEE 差异可能很有用。