Can Electronic Health Records Validly Estimate the Effects of Health System Interventions Aimed at Controlling Body Weight?

Abstract

Objective: This study aimed to compare weight collected at clinics and recorded in the electronic health record (EHR) with primary study-collected trial weights to assess the validity of using EHR data in future pragmatic weight loss or weight gain prevention trials.

Methods: For both the Track and Shape obesity intervention randomized trials, clinic EHR weight data were compared with primary trial weight data over the same time period. In analyzing the EHR weights, intervention effects were estimated on the primary outcome of weight (in kilograms) with EHR data, using linear mixed effects models.

Results: EHR weight measurements were higher on average and more variable than trial weight measurements. The mean difference and 95% CI were similar at all time points between the estimates using EHR and study-collected weights.

Conclusions: The results of this study can be used to help guide the planning of future pragmatic weight-related trials. This study provides evidence that body weight measurements abstracted from the EHR can provide valid, efficient, and cost-effective data to estimate treatment effects from randomized clinical weight loss and weight management trials. However, care should be taken to properly understand the data-generating process and any mechanisms that may affect the validity of these estimates.

Trial registration: ClinicalTrials.gov NCT01827800 NCT00938535.

© 2020 The Obesity Society.

Figures

Figure 1.. Comparison of EHR data and trial data estimated mean weight loss and intervention effect, and EHR-estimated long-term durability effects, from the Track Trial.

Panel A shows the estimated mean weight change separately in intervention and control, for the original Track trial data and the EHR data separately, along with the long-term EHR-estimated weight changes. Panel B displays the difference in weight change between intervention and control, estimating using separate mixed effects models for the original trial data (extracted from the Track main results paper) and the EHR data, along with the long-term (18 month) EHR-estimated treatment effect.

Figure 2.. Comparison of EHR data and trial data estimated mean weight loss and intervention effect from the Shape Trial.

Panel A shows the estimated mean weight change separately in intervention and control, for the original Shape trial data and the EHR data separately. Panel B displays the difference in weight change between intervention and control, estimating using separate mixed effects models for the original trial data (extracted from the Shape main results paper) and the EHR data.