Initial Validation of an Exercise “Vital Sign” in Electronic Medical Records

TLDR

The study aimed to assess the face and discriminant validity of an exercise vital sign (EVS) for use in outpatient electronic medical records. Using a cohort of 1.79 million adults, the authors compared EVS self‑reported exercise minutes to national survey data for face validity and applied multivariate Poisson regression to evaluate whether EVS discriminated between patient groups with differing physical activity levels based on demographics and health status. After 1.5 years, 86 % of eligible patients had an EVS, with 36.3 % inactive, 33.3 % insufficiently active, and 30.4 % sufficiently active; EVS patterns mirrored national surveys but were lower, and older, obese, minority, or higher‑burden patients were more likely inactive, confirming discriminant validity and suggesting EVS could link exercise to health‑care use and outcomes.

Abstract

Purpose The objective of this study is to describe the face and discriminant validity of an exercise vital sign (EVS) for use in an outpatient electronic medical record. Methods Eligible patients were 1,793,385 adults 18 yr and older who were members of a large health care system in Southern California. To determine face validity, median total self-reported minutes per week of exercise as measured by the EVS were compared with findings from national population-based surveys. To determine discriminant validity, multivariate Poisson regression models with robust variance estimation were used to examine the ability of the EVS to discriminate between groups of patients with differing physical activity (PA) levels on the basis of demographics and health status. Results After 1.5 yr of implementation, 86% (1,537,798) of all eligible patients had an EVS in their electronic medical record. Overall, 36.3% of patients were completely inactive (0 min of exercise per week), 33.3% were insufficiently active (more than 0 but less than 150 min·wk−1), and 30.4% were sufficiently active (150 min or more per week). As compared with national population-based surveys, patient reports of PA were lower but followed similar patterns. As hypothesized, patients who were older, obese, of a racial/ethnic minority, and had higher disease burdens were more likely to be inactive, suggesting that the EVS has discriminant validity. Conclusions We found that the EVS has good face and discriminant validity and may provide more conservative estimates of PA behavior when compared with national surveys. The EVS has the potential to provide information about the relationship between exercise and health care use, cost, and chronic disease that has not been previously available at the population level.