Collection and laboratory methods for dried blood spots for hemoglobin A1c and total and high-density lipoprotein cholesterol in population-based surveys.

BACKGROUND: The Health Measures at Home Study was a study designed to evaluate the feasibility of incorporating dried blood spots (DBS) collection into the National Health Interview Survey and to compare the proficiencies between field interviewers and health technicians in obtaining DBS. METHODS: DBS collection and venipuncture were attempted on 125 participants. The DBS were collected in the participant's home and venous blood was collected in the National Health and Nutrition Examination Survey (NHANES) mobile examination center. The DBS results were compared to venous results in the NHANES for the measurements of hemoglobin A1c (HbA1c) and total and high-density lipoprotein (HDL) cholesterol. RESULTS: Field interviewers and health technicians were able to collect the DBS for greater than 95% of participants. For DBS, health technicians and field interviewers were highly correlated for HbA1c (r=0.92) and total cholesterol (r=0.89), but not for HDL cholesterol (r=0.72). The DBS results of interviewers and health technicians compared to the venous method for HbA1c (r=0.90), but did not compare well for HDL cholesterol (r=0.64-0.66) and total cholesterol (r=0.65-0.67). CONCLUSION: DBS was comparable to venous HbA1c, but not for total and HDL cholesterol. Health technicians and field interviewers had similar performance for DBS methods, except HDL cholesterol.

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.

National Health and Nutrition Examination Survey: national youth fitness survey plan, operations, and analysis, 2012.

BACKGROUND: In October 2008, the federal government issued its first-ever Physical Activity Guidelines for Americans to provide science-based guidance on the types and amounts of physical activity that provide substantial health benefits for Americans (1). Guidelines for children and adolescents recommend 60 minutes or more of aerobic, muscle-strengthening, or bone-strengthening physical activity daily (1). While the number of children in the United States who meet the recommendations in the Physical Activity Guidelines is unknown, the percentage that is physically active in the United States may be declining. No recent national data exist on the fitness levels of children and adolescents. The National Health and Nutrition Examination Survey's (NHANES) National Youth Fitness Survey (NNYFS) was conducted in 2012 and collected data on physical activity and fitness levels for U.S. children and adolescents aged 3-15 years. OBJECTIVES: The objective of NNYFS was to provide national-level estimates of the physical activity and fitness levels of children, based on interview and physical examination data. Results from the survey are intended to contribute to the development of policies and programs to improve youth fitness nationally. The data also may be used in the development of national reference standards for measures of fitness and physical activity. Methods The NNYFS survey design used the design for NHANES, which is a multistage probability sample of the civilian noninstitutionalized resident population of the United States. NNYFS consisted of a household interview and a physical activity and fitness examination in a mobile examination center. A total of 1,640 children and adolescents aged 3-15 were interviewed, and 1,576 were examined.

National health and nutrition examination survey: plan and operations, 1999-2010.

Background-Starting in 1999, the National Health and Nutrition Examination Survey (NHANES) became a continuous, ongoing annual survey of the noninstitutionalized civilian resident population of the United States. A continuous survey allowed content to change to meet emerging needs. Objective-This report describes how NHANES for 1999-2010 was designed and implemented. NHANES is a national survey designed to provide national estimates on various health-related topics. Methods-The survey used in-person face-to-face interviews and physical examinations for data collection. Approximately 5,000 people per year participated in NHANES. The 5,000 people surveyed each year are representative of the entire U.S. population.

Assessing blood pressure accuracy of an aneroid sphygmomanometer in a national survey environment.

BACKGROUND: The "gold standard" employed for obtaining blood pressure (BP) for all the National Health and Nutrition Examination Surveys (NHANES) has been the mercury sphygmomanometer (HgS). Because of environmental concerns, there is a need to explore an alternative to HgS. METHODS: We compared the accuracy of the Welch Allyn 767 wall aneroid sphygmomanometer (AnS) to the HgS in children and adults and by BP cuff sizes. Each participant had three BP measurements per device recorded sequentially. The order of the devices and observer were random. A total of 727 individuals participating in the NHANES participated in the study. RESULTS: The mean AnS readings were not statistically significantly different from those of the HgS with the exception of systolic BP (SBP) in aged 8-17 years (mean difference 1.10, s.d. 4.87). There were no statistically significantly different by BP cuff sizes. Agreement for the prevalence of hypertension (BP ≥140 systolic or diastolic ≥90 mm Hg) was above chance (κ = 0. 81; sensitivity = 81%; specificity = 98%) with AnS readings underestimating by 1.66% (18.33 vs. 20%, P > 0.05) compared to the HgS reading. CONCLUSIONS: With the exception of SBP in ages 8-17 years, the AnS device readings were not significantly different from HgS readings by age or BP cuff sizes selection. Agreement for hypertension classification is good. An accurate and well-calibrated AnS could therefore provide an acceptable alternative to the use of a HgS in surveys, although with appropriate caution given the 81% sensitivity with regard to hypertension thresholds that was observed.

Assessing the validity of the Omron HEM-907XL oscillometric blood pressure measurement device in a National Survey environment.

Blood pressure (BP) readings taken by Omron HEM-907XL were compared with the results obtained using sphygmomanometer (HgS) in 509 individuals using 2002 Association for the Advancement of Medical Instrumentation (AAMI) criteria. With the exception of diastolic BP in youth ages 13 to 19 years (mean difference, -1.77 mm Hg; standard deviation, 8.65), the Omron device met the criteria. Agreement for hypertension (BP >or=140/90 mm Hg) was above chance (kappa=0.68) and, compared with HgS, Omron underestimated the prevalence of hypertension by 2.65%. The Omron and HgS measurements were highly correlated (r=0.94 for systolic BP and r=0.83 for diastolic BP). Both increased systolic and diastolic BP decreased device agreement (beta-coefficient=-0.10872, P<.0001; beta-coefficient=-0.25981, P<.0001, respectively). The Omron device meets AAMI criteria with the exception of diastolic BP in youth ages 13 to 19 years. However, Omron underestimated the prevalence of hypertension and device agreement decreases with increased systolic and diastolic BP.