Accelerometer Validation of Questionnaires Used in Clinical Settings to Assess MVPA

Introduction The exercise vital sign (EVS) and General Practice Physical Activity Questionnaire (GPPAQ) are questionnaires designed for clinical settings to identify individuals who are not meeting physical activity (PA) guidelines in the United States and United Kingdom, respectively. To date, neither has been objectively validated.

Methods Subjects (N = 76) from the United States (n = 38; age, 49 ± 20 yr) and United Kingdom (n = 38; age, 43 ± 21 yr) completed a health history questionnaire, wore an accelerometer for 7 d, and then completed the EVS and GPPAQ. Accelerometry, EVS, and GPPAQ data were scored to dichotomize subjects into groups of meeting (≥150 min of moderate-to-vigorous PA (MVPA) per week) or not meeting (<150 min of MVPA per week) the PA guidelines, and accelerometry was used as a criterion measure for comparing both questionnaires. The sensitivity and specificity of the EVS and GPPAQ were calculated to represent the ability of the questionnaires to identify subjects who did not and did meet the PA guidelines. Total MVPA accumulated in ≥10-min bouts were compared between accelerometry and the EVS using a 2 × 2 × 2 repeated measures ANOVA with one within-subjects effect (PA assessment method) and two between-subjects effects (gender and country). The alpha level was P = 0.05 for all analyses.

Results The EVS had marginally better sensitivity (59% vs 46%) and specificity (77% vs 50%) than the GPPAQ. The EVS grossly overestimated the minutes of MVPA when compared to accelerometry (P < 0.05) for all subjects, except UK women.

Conclusion In practice, the EVS and GPPAQ may not identify ∼50% of patients who should be advised to increase their PA. Therefore, physicians should advocate that all of their patients adopt an active lifestyle, including the achievement of ≥150 min of MVPA per week.