Supplementary Material for: Validity and discriminative value of activity questionnaires in youth with Type 1 Diabetes

Introduction: Prospective data quantifying physical activity levels in Australian youth with T1D is lacking. Structured questionnaire instruments may provide useful information but have not been evaluated in youth with type 1 diabetes (T1D). The objective of this study was to evaluate the validity of three paediatric physical activity (PA) questionnaires in young people with T1D and their ability to differentiate those not meeting PA guidelines of 60 minutes of moderate-to-vigorous PA (MVPA) per day from those who do.

Methods: Eighty youth with T1D (42 boys, 38 girls; age: 13.1 ± 2.6 years; BMI: 20.2 ± 3.9 kg.m-2; HbA1c: 58.5 ± 10.1 mmol/mol, T1D duration: 5.4 ± 3.1 years) wore an Actigraph GT3x accelerometer for 7 days and on day 8 completed three self-report PA instruments; i) the Physical Activity Questionnaire (PAQ); ii) Previous Day Physical Activity Recall (PDPAR) and; iii) a single item physical activity scale (SIPAS). Validity coefficients for each instrument using accelerometry-derived MVPA minutes were determined using Spearman’s correlation coefficient. Receiver operator characteristic (ROC) curves were generated and optimal cut-points determined.

Results: Mean daily MVPA minutes were 46.6 ± 25.5 minutes; 21/80 participants (26%) achieved an average of ≥ 60 MVPA minutes per day. The PAQ had the highest validity coefficient (r = 0.53; p < 0.001), followed by the single item tool (r = 0.39; p < 0.001) and PDPAR (r = 0.09; p = 0.4). Area under the ROC curve was 0.7, 0.5, and 0.7 for the PAQ, PDPAR, and single-item tools, respectively. Optimal cut points for sensitivity and specificity were i) a PAQ composite score of 2.8 (66.1% and 66.7%), ii) 75 MVPA minutes on the PDPAR (59.3% and 47.6%), and iii) 4.5 days on the SIPAS (71.2% and 38.1%).

Conclusion: The PAQ has moderate to high criterion validity and showed moderate ability to discriminate between T1D youth meeting PA guidelines from those who do not. The single-item question had low to moderate construct validity, while the PDPAR did not correlate with objectively measured PA levels. The feasibility of incorporating the PAQ into clinical care for youth with T1D warrants further evaluation.

引言：目前缺乏针对澳大利亚1型糖尿病（Type 1 Diabetes, T1D）青少年身体活动水平的前瞻性量化数据。结构化问卷工具或可提供有效信息，但尚未在1型糖尿病青少年群体中得到评估。本研究旨在评估三款儿童身体活动（Physical Activity, PA）问卷在1型糖尿病青少年中的效度，以及它们区分每日未达到60分钟中等至高强度身体活动（Moderate-to-vigorous PA, MVPA）指南标准人群与达标人群的能力。

方法：本研究纳入80名1型糖尿病青少年（男42名，女38名；年龄13.1±2.6岁；身体质量指数（Body Mass Index, BMI）20.2±3.9 kg·m⁻²；糖化血红蛋白（Hemoglobin A1c, HbA1c）58.5±10.1 mmol/mol；1型糖尿病病程5.4±3.1年）。所有受试者佩戴Actigraph GT3x加速度计7天，并于第8天完成三款自我报告身体活动问卷：i）身体活动问卷（Physical Activity Questionnaire, PAQ）；ii）前日身体活动回忆量表（Previous Day Physical Activity Recall, PDPAR）；iii）单条目身体活动量表（Single Item Physical Activity Scale, SIPAS）。以加速度计测得的MVPA时长为效标，采用斯皮尔曼相关系数计算各问卷的效度系数。绘制受试者工作特征（Receiver Operator Characteristic, ROC）曲线并确定最优截断点。

结果：受试者日均MVPA时长为46.6±25.5分钟；80名参与者中21名（26%）日均MVPA时长≥60分钟。PAQ的效度系数最高（r=0.53；p<0.001），其次为单条目工具（r=0.39；p<0.001），PDPAR的效度系数最低（r=0.09；p=0.4）。三款工具的ROC曲线下面积分别为0.7（PAQ）、0.5（PDPAR）与0.7（单条目工具）。区分灵敏度与特异性最优的截断点分别为：i）PAQ综合得分2.8（灵敏度66.1%，特异度66.7%）；ii）PDPAR量表中MVPA时长75分钟（灵敏度59.3%，特异度47.6%）；iii）SIPAS量表中活跃天数4.5天（灵敏度71.2%，特异度38.1%）。

结论：PAQ具有中至高的效标效度，且具备中等能力区分1型糖尿病青少年中是否达到身体活动指南标准的人群。单条目问卷具有低至中等的结构效度，而PDPAR与客观测得的身体活动水平无相关性。将PAQ纳入1型糖尿病青少年临床护理的可行性有待进一步评估。