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Betsy L Cadwell

Publications and source records attributed to Betsy L Cadwell.

7 recordsLinked to original sources
PubMed2005

Methods for capture-recapture analysis when cases lack personal identifiers.

Methods for estimating the size of a closed population from a capture-recapture study require the availability of unique identifiers on each of two lists. These identifiers are used to identify the number of individuals appearing on both lists. When the number of individuals appearing on both lists cannot be determined with certainty from the data, matching between the lists is problematic. In this paper, we develop a weighted estimator to account for all possible matches between two lists. A bootstrap procedure is proposed for estimation. To illustrate the methods, we used two lists that recorded New York State (NYS) hospitalizations due to pertussis in 1996 to estimate the number of persons hospitalized for pertussis in NYS that year.

Algorithms↗
PubMed2005

Secular trends in cardiovascular disease risk factors according to body mass index in US adults.

CONTEXT: Prevalence of obesity in the United States has increased dramatically in recent decades, but the magnitude of change in cardiovascular disease (CVD) risk factors among the growing proportion of overweight and obese Americans remains unknown. OBJECTIVE: To examine 40-year trends in CVD risk factors by body mass index (BMI) groups among US adults aged 20 to 74 years. DESIGN, SETTING, AND PARTICIPANTS: Analysis of 5 cross-sectional, nationally representative surveys: National Health Examination Survey (1960-1962); National Health and Nutrition Examination Survey (NHANES) I (1971-1975), II (1976-1980), and III (1988-1994); and NHANES 1999-2000. MAIN OUTCOME MEASURES: Prevalence of high cholesterol level (> or =240 mg/dL [> or =6.2 mmol/L] regardless of treatment), high blood pressure (> or =140/90 mm Hg regardless of treatment), current smoking, and total diabetes (diagnosed and undiagnosed combined) according to BMI group (lean, <25; overweight, 25-29; and obese, > or =30). RESULTS: The prevalence of all risk factors except diabetes decreased over time across all BMI groups, with the greatest reductions observed among overweight and obese groups. Compared with obese persons in 1960-1962, obese persons in 1999-2000 had a 21-percentage-point lower prevalence of high cholesterol level (39% in 1960-1962 vs 18% in 1999-2000), an 18-percentage-point lower prevalence of high blood pressure (from 42% to 24%), and a 12-percentage-point lower smoking prevalence (from 32% to 20%). Survey x BMI group interaction terms indicated that compared with the first survey, the prevalence of high cholesterol in the fifth survey had fallen more in obese and overweight persons than in lean persons (P<.05). Survey x BMI changes in blood pressure and smoking were not statistically significant. Changes in risk factors were accompanied by increases in lipid-lowering and antihypertensive medication use, particularly among obese persons. Total diabetes prevalence was stable within BMI groups over time, as nonsignificant 1- to 2-percentage-point increases occurred between 1976-1980 and 1999-2000. CONCLUSIONS: Except for diabetes, CVD risk factors have declined considerably over the past 40 years in all BMI groups. Although obese persons still have higher risk factor levels than lean persons, the levels of these risk factors are much lower than in previous decades.

Adult↗
PubMed2005

Prevalence of impaired fasting glucose and its relationship with cardiovascular disease risk factors in US adolescents, 1999-2000.

OBJECTIVE: PEDIATRICS (ISSN 0031 4005). Published in the public domain by the American Academy of Pediatrics. Several studies have reported increases in the occurrence of type 2 diabetes in youths. People with prediabetic states such as impaired fasting glucose (IFG) are at increased risk for developing diabetes and cardiovascular disease (CVD). The objective of this study was to examine the prevalence of IFG and its relationship with overweight and CVD risk factors in a nationally representative sample of US adolescents who were aged 12 to 19 years. METHODS: We used data from the 1999-2000 National Health and Nutrition Examination Survey (NHANES). Adolescents who had fasted for 8 hours or more were included in the study (n = 915). IFG was defined as a fasting glucose of 100 to 125 mg/dL. Participants were classified as overweight when their age- and gender-specific BMI was > or = 95th percentile and as at-risk for overweight when their BMI was > or = 85th and < 95th percentile. RESULTS: In 1999-2000, the prevalence of IFG in US adolescents was 7.0% and was higher in boys than in girls (10.0% vs 4.0%). Prevalence of IFG was higher in overweight adolescents (17.8%) but was similar in those with normal weight and those who were at risk for overweight (5.4% vs 2.8%). The prevalence of IFG was significantly different across racial/ethnic groups (13.0%, 4.2%, and 7% in Mexican Americans, non-Hispanic black individuals, and non-Hispanic white individuals, respectively). Adolescents with IFG had significantly higher mean hemoglobin A1c, fasting insulin, total and low-density lipoprotein cholesterol, triglycerides, and systolic blood pressure and lower high-density lipoprotein cholesterol than those with normal fasting glucose concentrations. CONCLUSIONS: These data, representing 27 million US adolescents, reveal a very high prevalence of IFG (1 in 10 boys and 1 in 25 girls) among adolescents; the condition affects 1 in every 6 overweight adolescents. Adolescents with IFG have features of insulin resistance and worsened CVD risk factors. Evidence for prevention is still forthcoming in this age group.

Adolescent↗
PubMed2004

Thirty-year trends in cardiovascular risk factor levels among US adults with diabetes: National Health and Nutrition Examination Surveys, 1971-2000.

Among US adults with diabetes, using data from the National Health and Nutrition Examination Survey for 1971-1974, 1976-1980, 1988-1994, and 1999-2000, the authors describe 30-year trends in total cholesterol, blood pressure, and smoking levels. Using Bayesian models, the authors calculated mean changes per year and 95% credible intervals for age-adjusted mean total cholesterol and blood pressure levels and the prevalence of high total cholesterol (> or =5.17 mmol/liter), high blood pressure (systolic blood pressure: > or =140 mmHg and/or diastolic blood pressure: > or =90 mmHg), and smoking. Between 1971-1974 and 1999-2000, mean total cholesterol declined from 5.95 mmol/liter to 5.48 mmol/liter (-0.02 (95% credible interval: -0.03, -0.01) mmol/liter per year). The proportion with high cholesterol decreased from 72% to 55%. Mean blood pressure declined from 146/86 mmHg to 134/72 mmHg (systolic blood pressure: -0.5 (95% credible interval: -1.1, 0.5) mmHg per year; diastolic blood pressure: -0.6 (95% credible interval: -1.0, -0.03) mmHg per year). The proportion with high blood pressure decreased from 64% to 37%, and smoking prevalence decreased from 32% to 17%. Although these trends are encouraging, still one of two people with diabetes has high cholesterol, one of three has high blood pressure, and one of six is a smoker.

Adult↗
PubMed2004

Trends in the prevalence and ratio of diagnosed to undiagnosed diabetes according to obesity levels in the U.S.

OBJECTIVE: To examine trends in the prevalence of diagnosed and undiagnosed diabetes and the proportion of total cases previously diagnosed, according to obesity status in the U.S. over the past 40 years. RESEARCH DESIGN AND METHODS: We assembled data from five consecutive cross-sectional national surveys: National Health Examination Survey I (1960-1962), National Health and Nutrition Examination Survey (NHANES) I (1971-1974), NHANES II (1976-1980), NHANES III (1988-1994), and NHANES 1999-2000. Diagnosed diabetes was ascertained, and height and weight were measured in adults aged 20-74 years in all surveys. In NHANES II, NHANES III, and NHANES 1999-2000, a fasting glucose level > or =126 mg/dl was used to identify cases among individuals not reporting diabetes. Design-based analyses and Bayesian models estimate the probability that prevalence of diabetes increased within four BMI groups (<25, 25-29, 30-34, and > or =35 kg/m2). RESULTS: In the U.S. population aged 20-74 years between 1976-1980 and 1999-2000, significant increases in the prevalence of diagnosed diabetes (3.3-5.8%, probability >99.9%) were accompanied by nonsignificant increases in undiagnosed diabetes (2.0-2.4%, 66.6%). This resulted in an increase in total diabetes (5.3-8.2%, >99.9%) and a modest nonsignificant increase in the proportion of cases that were diagnosed (62-70%, 62.4%). However, these trends varied considerably by BMI level. In individuals with BMI > or =35 kg/m2, diagnosed diabetes increased markedly (from 4.9% in 1960, to 8.6% during 1976-1980, to 15.1% in 1999-2000; probability >99.9%), whereas undiagnosed diabetes declined considerably (12.5% during 1976-1980 to 3.2% in 1999-2000, probability of increase 4.5%) Therefore, the proportion of total diabetes cases that were diagnosed increased from 41 to 83% (probability 99.9%) among individuals with BMI > or =35 kg/m2. By comparison, changes in prevalence within BMI strata <35 kg/m2 were modest and there was no increase in the percent of total cases that were diagnosed. CONCLUSIONS: National surveys over the last several decades have found large increases in diagnosed diabetes, particularly in overweight and obese individuals, but this has been accompanied by large decreases in undiagnosed diabetes only among individuals with BMI > or =35 kg/m2. This suggests that improvements in diabetes awareness and detection are most prominent among this subgroup.

Adult↗