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Papers by rechal johnson

Journal of the American Dietetic …, Jan 1, 1996

This study determined the accuracy of the multiple-pass 24-hour recall method for estimating ener... more This study determined the accuracy of the multiple-pass 24-hour recall method for estimating energy intake in young children by comparing it with measurements of total energy expenditure made using the doubly labeled water method. Three multiple-pass 24-hour recalls were obtained over a 14-day period to estimate mean energy intake. Total energy expenditure was measured over the same 14-day period under free-living conditions using the doubly labeled water technique. Twenty-four children between the ages of 4 and 7 years were tested at the General Clinical Research Center/Sims Obesity Nutrition Research Center at the University of Vermont. t Tests, paired t tests, Pearson product-moment correlation coefficients, pairwise comparison to show relative bias and limits of agreement, and regression analysis were used to test the relationships among study variables. No difference was found between 3-day mean energy intake and total energy expenditure for the group (t = 2.07, P = .65). The correlation between individual measures of energy intake and total energy expenditure was not statistically significant (r = .25, P = .24). Data from 3 days of multiple-pass 24-hour recalls were sufficient to make valid group estimates of energy intake. The method was not precise for individual measurements of energy intake.

Pediatrics, Jan 1, 1998

To examine individual changes in energy expenditure and physical activity during prepubertal grow... more To examine individual changes in energy expenditure and physical activity during prepubertal growth in boys and girls. Total energy expenditure (TEE), resting energy expenditure, physical activity-related energy expenditure, reported physical activity, and fat and fat-free mass were measured three times over 5 years in 11 boys (5.3 +/- 0.9 years at baseline) and 11 girls (5.5 +/- 0.9 years at baseline). Four-year increases in fat ( approximately 6 kg) and fat-free mass ( approximately 10 kg) and resting energy expenditure ( approximately 200 kcal/day) were similar in boys and girls. In boys, TEE increased at each measurement year, whereas in girls, there was an initial increase from age 5.5 (1365 +/- 330 kcal/day) to age 6.5 (1815 +/- 392 kcal/day); however, by age 9.5, TEE was reduced significantly (1608 +/- 284 kcal/day) with no change in energy intake. The gender difference in TEE changes over time was explained by a 50% reduction in physical activity (kcal/day and hours/week) in girls between the ages of 6.5 and 9.5. These data suggest a gender dimorphism in the developmental changes in energy expenditure before adolescence, with a conservation of energy use in girls achieved through a marked reduction in physical activity.

The Lancet, Jan 1, 1999

In the UK, kidneys are exchanged between centres on the basis of matching for HLA. We analysed va... more In the UK, kidneys are exchanged between centres on the basis of matching for HLA. We analysed various factors that might affect graft outcome to establish whether exchange of kidneys on this basis remains valid. 6363 primary cadaveric renal transplants carried out in 23 centres in the UK between 1986 and 1993 were used in the analysis. 6338 (99.6%) patients who underwent transplantation were followed up at 1 year. 5-year follow-up data were available for 2907 (97.8%) of the 2972 patients who survived to 5 years. We made random checks to validate the data. A multifactorial analysis with Cox's proportional hazards models was used to analyse factors that had a possible effect on graft outcome. To ensure that the analysis of matching was constant during the 8-year study, our analysis was based on the HLA antigens used for organ exchange (11 A locus antigens, 27 B locus antigens, and 12 DR locus antigens). We assessed overall outcome at 5 years and during three periods after transplantation at: 0-3 months, 3-36 months, and after 36 months. The following factors were significantly associated with graft outcome in the multifactorial analysis: year of graft, age of donor, age of recipient, whether the recipient had diabetes, cause of donor's death, cold ischaemic time, transport of kidneys, transplant centre, and matching for HLA. The best outcome was achieved with kidneys that had no mismatches at HLA-A, HLA-B, and HLA-DR loci (000 mismatches). The next most favourable outcome was achieved with one mismatch at either A or B loci or one mismatch at both the A and B , but no mismatch at the DR locus (100, 010, or 110 mismatches). Age of the donor and recipient had a significant effect on transplant outcome: older age was associated with increased risk of graft failure. Various factors affect the outcome of primary cadaveric renal transplantation, particularly the age of the donor and the recipient. However, the effect of matching for HLA remains a strong one and fully justifies the continuing policy in the UK of exchanging kidneys on the basis of HLA matching, especially to recipients when there is a 000 mismatch for HLA between donor and recipient. On the basis of this analysis, a new allocation scheme for kidneys was introduced in the UK in 1998. During the first 9 months of the scheme, there has been a doubling of the number of HLA-000 mismatched kidneys transplanted.

American Journal of …, Jan 1, 1996

Journal of the American Dietetic Association, Jan 1, 2004

Journal of General …, Jan 1, 2004

OBJECTIVESTo determine: 1) whether racial and ethnic differences exist in patients’ perceptions o... more OBJECTIVESTo determine: 1) whether racial and ethnic differences exist in patients’ perceptions of primary care provider (PCP) and general health care system–related bias and cultural competence; and 2) whether these differences are explained by patient demographics, source of care, or patient-provider communication variables.DESIGNCross-sectional telephone survey.SETTINGThe Commonwealth Fund 2001 Health Care Quality Survey.SUBJECTSA total of 6,299 white, African-American, Hispanic, and Asian adults.MEASUREMENTS AND MAIN RESULTSInterviews were conducted using random-digit dialing; oversampling respondents from communities with high racial/ethnic minority concentrations; and yielding a 54.3% response rate. Main outcomes address respondents’ perceptions of their PCPs’ and health care system–related bias and cultural competence; adjusted probabilities (Pr) are reported for each ethnic group. Most racial/ethnic differences in perceptions of PCP bias and cultural competence were explained by demographics, source of care, and patient–physician communication variables. In contrast, racial/ethnic differences in patient perceptions of health care system–wide bias and cultural competence persisted even after controlling for confounders: African Americans, Hispanics, and Asians remained more likely than whites (P < .001) to perceive that: 1) they would have received better medical care if they belonged to a different race/ethnic group (Pr 0.13, Pr 0.08, Pr 0.08, and Pr 0.01, respectively); and 2) medical staff judged them unfairly or treated them with disrespect based on race/ethnicity (Pr 0.06, Pr 0.04, Pr 0.06, and Pr 0.01, respectively) and how well they speak English (Pr 0.09, Pr 0.06, Pr 0.06, and Pr 0.03, respectively).CONCLUSIONWhile demographics, source of care, and patient–physician communication explain most racial and ethnic differences in patient perceptions of PCP cultural competence, differences in perceptions of health care system–wide bias and cultural competence are not fully explained by such factors. Future research should include closer examination of the sources of cultural bias in the US medical system.

American Journal of …, Jan 1, 2004

Annals of Internal …, Jan 1, 2003