Validity of medical chart weights and heights for obese pregnant women

To determine the validity of adult body weights and heights recorded in electronic medical records (EMRs) in the course of routine medical care.

EMRs allow the potential use of data collected in the course of routine medical care for a variety of research applications in many fields including epidemiology and comparative effectiveness studies. However, researchers familiar with carefully controlled measurement protocols typically used in clinical trials may question the validity of data collected in the course of routine clinical care.

Weights and heights collected during a research project that focused on weight gain during pregnancy were compared to weight and height measurements coincidently recorded in the research participant's medical records. For weight measures (N=102), data recorded within ±14 days were compared, and for height measures (N=114), data recorded within ±5 years were compared. We assessed agreement between medical and research measurements using the concordance and intraclass correlation coefficients, and Bland and Altman's limits of agreement.

The mean research and medical record weight measurements were 99.3 kg and 99.2 kg, respectively. The concordance and intraclass correlation coefficients for weight had similar estimates of .999 and 95 percent confidence intervals [.998, .999]. The 95 percent limits of agreement were -1.5 kg and +1.7 kg. The mean research and medical height measurements were 1.646 m and 1.654 m, respectively, and the concordance and intraclass correlation coefficients for height were .941 and .942, respectively. The 95 percent limits of agreement were -.031 m and +.047 m.

For pregnant women, body weights documented in the medical record are exchangeable with body weights recorded in a research setting. Height measurements recorded in the medical records were not in as close agreement as weights, but concordance between medical record and research height measurements are high enough to allow them to be used epidemiological and comparative effectiveness research.