Biomedical subjects

Arnold D Kester

Publications and source records attributed to Arnold D Kester.

4 recordsLinked to original sources

PubMed2005

Measuring free-living energy expenditure and physical activity with triaxial accelerometry.

OBJECTIVE: To investigate the ability of a newly developed triaxial accelerometer to predict total energy expenditure (EE) (TEE) and activity-related EE (AEE) in free-living conditions. RESEARCH METHODS AND PROCEDURES: Subjects were 29 healthy subjects between the ages of 18 and 40. The Triaxial Accelerometer for Movement Registration (Tracmor) was worn for 15 consecutive days. Tracmor output was defined as activity counts per day (ACD) for the sum of all three axes or each axis separately (ACD-X, ACD-Y, ACD-Z). TEE was measured with the doubly labeled water technique. Sleeping metabolic rate (SMR) was measured during an overnight stay in a respiration chamber. The physical activity level was calculated as TEE x SMR(-1), and AEE was calculated as [(0.9 x TEE) - SMR]. Body composition was calculated from body weight, body volume, and total body water using Siri's three-compartment model. RESULTS: Age, height, body mass, and ACD explained 83% of the variation in TEE [standard error of estimate (SEE) = 1.00 MJ/d] and 81% of the variation in AEE (SEE = 0.70 MJ/d). The partial correlations for ACD were 0.73 (p < 0.001) and 0.79 (p < 0.001) with TEE and AEE, respectively. When data on SMR or body composition were used with ACD, the explained variation in TEE was 90% (SEE = 0.74 and 0.77 MJ/d, respectively). The increase in the explained variation using three axes instead of one axis (vertical) was 5% (p < 0.05). DISCUSSION: The correlations between Tracmor output and EE measures are the highest reported so far. To measure daily life activities, the use of triaxial accelerometry seems beneficial to uniaxial.

Acceleration↗

PubMed2005

Femoral fit predicts radiologic changes, but not clinical results, in Mallory-head total hip arthroplasties.

We prospectively studied the clinical and radiologic results of three groups of patients: 89 patients who had standard primary total hip replacements; 63 patients with hip dysplasia who had primary total hip replacements; and 48 patients who had revision total hip replacements. We studied the differences in clinical and radiologic behaviors of a titanium hydroxyapatite-coated stem with variations in the tightness of fit of the prosthesis in the femoral canal, operative group, stem size, grade of osteoporosis, and morphometric features of the femur. The clinical results in all three groups are slightly favorable for the standard primary group. Pain relief and stem survival in the three groups were similar to those reported in other studies regarding cementless prostheses. Nontight femoral fit significantly positively influenced the development of cancellous densification; however, the presence of osteoporosis also contributed to the formation of cancellous densification. Only tight femoral canal fit significantly positively influenced the development of cortical thickening independent of other parameters. There was no correlation between clinical parameters and the radiologic phenomena in either of the groups.

Adult↗

PubMed2003

Cholesterol changes in coronary patients after a short behavior modification program.

Serum cholesterol changes after an 8-week behavior modification program for patients with coronary artery disease (CAD) were studied in a randomized controlled clinical trial. Acute myocardial infarction (AMI) or coronary artery bypass grafting (CABG) patients were randomly assigned to the intervention (N = 94) or to usual care (N = 90). After 9 months' follow-up the intervention was effective in reducing total cholesterol and LDL cholesterol levels, particularly in patients with high baseline lipid levels. After correcting for changes in dose of statins during follow-up, effects were weakened, but for patients with high baseline cholesterol levels favorable effects remained. In these patients, the intervention group showed a decline of total cholesterol and LDL cholesterol levels of 20% and 29%, respectively, compared to a 12% and 19% reduction in the control group (p <.01). These effects could not be explained by changes in dietary fat consumption. An unexpected finding was a lower increase in HDL cholesterol in the intervention group than in the control group.

Aged↗

PubMed2003

The efficacy of an automated feedback system for general practitioners.

OBJECTIVE: An automated feedback system that produces comments about the non-adherence of general practitioners (GPs) to accepted practice guidelines for ordering diagnostic tests was developed. Before implementing the automated feedback system in daily practice, we assessed the potential effect of the system on the test ordering behaviour of GPs. DESIGN: We used a randomised controlled trial with balanced block design. SETTING: Five times six participant groups of GPs in a computer laboratory setting. INTERVENTION: The GPs reviewed a random sample of 30 request forms they filled in earlier that year. If deemed necessary, they could make changes in the tests requested. Next, the system displayed critical comments about their non-adherence to the guidelines as apparent from the (updated) request forms. SUBJECTS: Twenty-four randomly selected GPs participated. MAIN OUTCOME MEASURES: The number of requested diagnostic tests (17% with 95% confidence interval [CI]: 12-22%) and the fraction of tests ordered that were not in accordance with the practice guidelines (39% with 95% CI: 28-51%) decreased due to the comments of the automated feedback system. The GPs accepted 362 (50%) of the 729 reminders. IMPLICATIONS: Although our experiment cannot predict the size of the actual effect of the automated feedback system in daily practice, the observed effect may be seen as the maximum achievable.

Decision Support Systems, Clinical↗