Validity and Reliability of the Exercise Vital Signs Questionnaire in a Diverse Urban Population

Abstract

The Exercise Vital Signs (EVS) is a new brief (<30 seconds) physical activity (PA) questionnaire used by the Exercise is Medicine initiative within the American College of Sports Medicine. While the criterion validity of the EVS has been evaluated in a select number of ethnic groups, research on the validity and reliability of the EVS questionnaire in a diverse, urban sample is lacking. PURPOSE: To determine the validity and reliability of the EVS in a diverse, urban sample. METHODS: An ethnically-diverse sample (White 33%, Latino 31%, Asian 21%, Black 15%) of N=39 participants [age 31(10.4)] were asked to wear an accelerometer at the hip for 9 days and to complete the EVS at the beginning (T1) and end (T2) of the wear period. The criterion validity of the EVS-estimated minutes of weekly moderate-vigorous PA (MVPA) was determined against accelerometer-derived estimates of the total time spent in ≥10min bouts of MVPA using Spearman’s correlations. EVS responses were used to predict subjects who were confirmed to meet current PA guidelines of ≥150 MVPA min/week via accelerometry using logistic regression. The EVS receiver operating characteristic area under the curve (AUC), sensitivity, and specificity were calculated. The concurrent validity of the EVS MVPA estimates was tested against accelerometer- derived steps/day using Spearman’s correlations. The intraclass correlation coefficient (ICC) was calculated between the EVS responses at T1 and T2 in order to evaluate questionnaire test-retest reliability. RESULTS: Reliability for the EVS questionnaire was strong (ICC= .98). There was a moderate correlation (rho= .58 at T2, p= <.01) between the EVS-estimated PA minutes/ week and the accelerometer-derived MVPA minutes/week. There was also a moderate correlation (rho= .43 at T2, p= .006) between EVS-determined PA minutes/week and the accelerometer-derived steps/day. The T2 EVS specificity and sensitivity were 56% and 78%, respectively, and the AUC was 0.74. CONCLUSIONS: In a diverse, urban sample, the EVS questionnaire has acceptable validity and high test-retest reliability. The EVS may be a useful tool for identifying ethnically-diverse individuals not meeting current PA guidelines. Further research in larger ethnically-diverse samples is needed.