Comparison of in-home collection of physical measurements and biospecimens with collection in a standardized setting: the health measures at home study.

OBJECTIVES: Collection of physical measurements and biospecimens in the home may be an efficient way to obtain objective health measurements. This study assesses differences between collection in the home and a standardized setting.

METHODS: Participants had physical measurements and biospecimens taken in the National Health and Nutrition Examination Survey mobile examination center (MEC). Then, they had height and weight measured in the MEC using portable equipment. In the home, participants had height, weight, and blood pressure measured and dried blood spots collected using portable equipment. Two complete examinations were done in the home: one by a health technician and one by a field interviewer.

RESULTS: Home environments were less standardized and presented more challenges to examiners. Correlations between all four height measurements and all four weight measurements were higher than 99%. Mean differences in height (0.3 cm) and weight (0.4 kg) were small but statistically significant. The home measurements perfectly or near-perfectly classified participants as obese relative to the standardized MEC examination.

CONCLUSIONS: The selected physical measurements can be collected in the home by field interviewers using portable equipment. Before adding home collection of physical measurements to household interview surveys, further research should be done to examine the impact of these changes on interviewer training, participant recruitment, and participant response rates.