David Kleinbaum - Academia.edu (original) (raw)

Papers by David Kleinbaum

Statistics for Biology and Health, 2010

In this chapter, the discussion of methods to analyze outcome variables that have dichotomous cor... more In this chapter, the discussion of methods to analyze outcome variables that have dichotomous correlated responses is expanded to include approaches other than GEE. Three other analytic approaches are discussed. These include the alternating logistic regressions algorithm, conditional logistic regression, and the generalized linear mixed model approach.

Clinical journal of the American Society of Nephrology : CJASN, Jan 21, 2015

Molecular evidence suggests that levels of vitamin D are associated with kidney function loss. St... more Molecular evidence suggests that levels of vitamin D are associated with kidney function loss. Still, population-based studies are limited and few have considered the potential confounding effect of baseline kidney function. This study evaluated the association of serum 25-hydroxyvitamin D with change in eGFR, rapid eGFR decline, and incidence of CKD and albuminuria. Baseline (2003-2006) and 5.5-year follow-up data from a Swiss adult general population were used to evaluate the association of serum 25-hydroxyvitamin D with change in eGFR, rapid eGFR decline (annual loss >3 ml/min per 1.73 m(2)), and incidence of CKD and albuminuria. Serum 25-hydroxyvitamin D was measured at baseline using liquid chromatography-tandem mass spectrometry. eGFR and albuminuria were collected at baseline and follow-up. Multivariate linear and logistic regression models were used considering potential confounding factors. Among the 4280 people included in the analysis, the mean±SD annual eGFR change wa...

Bulletin of the New York Academy of Medicine, 1978

EPIDEMIOLOGICAL investigations of the effects of air pollution on community health emphasize the ... more EPIDEMIOLOGICAL investigations of the effects of air pollution on community health emphasize the measurement of disease status in polluted (exposed) and less polluted (unexposed) communities. The relative risk, or ratio of disease incidence in exposed to nonexposed populations, is usually computed as the measure of effect, that is, the association between exposure and disease, in cohort or follow-up studies, while the prevalence ratio is the similar measure of effect in cross-sectional studies. (Case-control studies are seldom carried out in air-pollution investigations, and will not be discussed here.) Epidemiologists take pains to determine accurately the presence or absence of disease in each exposure category and to ascertain that disease frequencies in each group are not affected by confounding factors. Characterization of exposure status generally receives less attention in epidemiological studies than measurements of disease and of potential confounding factors. Most air-pollution studies depend on air-monitoring data collected by some public agency for purposes other than evaluation of health status. Even when air-monitoring stations are specifically set in place for a health study, the epidemiologist relies on people trained in engineering or other nonhealth disciplines to furnish accurate measurements of ambient air quality in the neighborhoods of study populations, and uses these measurements to assign population groups to exposure categories.

Annals of Epidemiology, 2015

Purpose-Medications can have unintended effects. High medication use populations may benefit from... more Purpose-Medications can have unintended effects. High medication use populations may benefit from increased regimen oversight. Limited knowledge exists concerning racial and regional polypharmacy variation. We estimated total medication distributions (excluding supplements) of American black and white adults and assessed racial and regional polypharmacy variation. Methods-REasons for Geographic And Racial Differences in Stroke (REGARDS) cohort data (N=30,239 U.S. blacks/whites ages ≥45 years) were analyzed. Home pill-bottle inspections assessed the last two weeks' medications. Polypharmacy (≥ 8 medications) was determined by summing prescription and/or OTC ingredients. Population-weighted logistic regression assessed polypharmacy's association with census region, race, and gender. Results-The mean ingredient number was 4.12 (SE = 0.039), with 15.7% of REGARDS using ≥8 ingredients. In crude comparisons, women used more medications than men, and blacks and whites reported similar mean ingredients. A cross-sectional, logistic model adjusting for demographics, socioeconomics, and comorbidities showed increased polypharmacy prevalence in

BMJ Open, 2012

Objectives: Hypothesising that couples' voluntary counselling and testing (CVCT) promotions can i... more Objectives: Hypothesising that couples' voluntary counselling and testing (CVCT) promotions can increase CVCT uptake, this study identified predictors of successful CVCT promotion in Lusaka, Zambia.

ActivEpi Companion Textbook, 2012

PLoS neglected tropical diseases, 2014

Lymphedema management programs have been shown to decrease episodes of adenolymphangitis (ADLA), ... more Lymphedema management programs have been shown to decrease episodes of adenolymphangitis (ADLA), but the impact on lymphedema progression and of program compliance have not been thoroughly explored. Our objectives were to determine the rate of ADLA episodes and lymphedema progression over time for patients enrolled in a community-based lymphedema management program. We explored the association between program compliance and ADLA episodes as well as lymphedema progression. A lymphedema management program was implemented in Odisha State, India from 2007-2010 by the non-governmental organization, Church's Auxiliary for Social Action, in consultation with the Centers for Disease Control and Prevention. A cohort of patients was followed over 24 months. The crude 30-day rate of ADLA episodes decreased from 0.35 episodes per person-month at baseline to 0.23 at 24 months. Over the study period, the percentage of patients who progressed to more severe lymphedema decreased (P-value = 0.0...

Sexually Transmitted Diseases, 2011

Background-Annual chlamydia screening is recommended for all sexually active women aged <25 years... more Background-Annual chlamydia screening is recommended for all sexually active women aged <25 years. Substantial limitations exist in ascertaining chlamydia trends. Reported case rates have increased likely due to increased screening and improved test technology. Other data suggest that prevalence has decreased. Methods-Data from the Infertility Prevention Project (IPP), a national chlamydia screening program, were used to assess trends in chlamydia positivity from 2004 to 2008 among women aged 15 to 24 years who were tested in family planning clinics reporting data to IPP. Using the clinic as the unit of analysis, a correlated, longitudinal data analysis with a random intercept was conducted among clinics reporting ≥3 years of data during the analysis time-frame. Sensitivity analyses were performed to address the impact of various clinic participation levels in addition to the assessment of various correlation structures. Results-Over 5 million chlamydia tests were reported to IPP family planning clinics from 2004 to 2008. A majority of tests were conducted among white women (clinic-specific mean: 63.2%, inter-quartile range: 37.6%-91.5%); the clinic-specific mean percent of tests conducted among black women was 17.9% (interquartile range: 0.8%-25.7%). Overall chlamydia positivity from 2004 to 2008 was 7.0%. The odds ratio associated with a single year change (1.00; 95% confidence interval: 0.99, 1.00) suggested that chlamydia positivity did not change from 2004 to 2008, after controlling for clinic-specific population factors (age, race, test usage, and geography). Conclusions-Findings support previous analyses suggesting that chlamydia prevalence is not increasing despite apparent increasing rates based on case reports.

Molecular Psychiatry, 2005

Depression and obesity have become major health problems with increasing prevalence. Given the li... more Depression and obesity have become major health problems with increasing prevalence. Given the limited effectiveness of treatment for weight problems, the identification of novel, potentially modifiable risk factors may provide insights on new preventive approaches to obesity. The purpose of this study was to test the hypothesis that depressive symptoms during childhood are associated with weight gain and obesity during young adulthood. Participants were from a prospective community-based cohort study of young adults (N ¼ 591) followed between ages 19 and 40 years. The sample was stratified to increase the probability of somatic and psychological syndromes. Information was derived from six subsequent semistructured diagnostic interviews conducted by professionals over 20 years. The outcome measures were body mass index (BMI) and obesity (BMI430). Among women, depressive symptoms before age 17 years were associated with increased weight gain (4.8 vs 2.6% BMI increase per 10 years) representing greater risk for adult obesity (hazard ratio ¼ 11.52, Po0.05). Among men, only after controlling for confounders, depressive symptoms before age 17 years were associated with increased weight gain (6.6 vs 5.2% BMI increase per 10 years) in adulthood but not with occurrence of obesity. These associations between childhood depressive symptoms and adult body weight were adjusted for baseline body weight, a family history of weight problems, levels of physical activity, consumption of alcohol and nicotine, and demographic variables. As the magnitude of the associations was high, and depression during childhood is a prevalent and treatable condition, this finding may have important clinical implications for the prevention and treatment of obesity. Whether the results of this study are limited to populations with elevated levels of psychopathology remains to be tested.

Journal of the American Society of Nephrology, 2008

Poverty is associated with increased risk of ESRD, but its contribution to observed racial differ... more Poverty is associated with increased risk of ESRD, but its contribution to observed racial differences in disease incidence is not well-defined. To explore the contribution of neighborhood poverty to racial disparity in ESRD incidence, we analyzed a combination of US Census and ESRD Network 6 data comprising 34,767 patients that initiated dialysis in Georgia, North Carolina, or South Carolina between January 1998 and December 2002. Census tracts were used as the geographic units of analysis, and the proportion of the census tract population living below the poverty level was our measure of neighborhood poverty. Incident ESRD rates were modeled using two-level Poisson regression, where race, age and gender were individual covariates (level 1), and census tract poverty was a neighborhood covariate (level 2). Neighborhood poverty was strongly associated with higher ESRD incidence for both blacks and whites. Increasing poverty was associated with a greater disparity in ESRD rates between blacks and whites, with the former at greater risk. This raises the possibility that blacks may suffer more from lower socioeconomic conditions than whites. The disparity persisted across all poverty levels. The reasons for increasingly higher ESRD incidence among US blacks as neighborhood poverty increases remain to be explained.

Journal of the American Society of Nephrology, 2009

Racial disparities persist in the United States renal transplantation process. Previous studies s... more Racial disparities persist in the United States renal transplantation process. Previous studies suggest that the distance between a patient's residence and the transplant facility may associate with disparities in transplant waitlisting. We examined this possibility in a cohort study using data for incident, adult ESRD patients (1998 to 2002) from the ESRD Network 6, which includes Georgia, North Carolina, and South Carolina. We linked data with the United Network for Organ Sharing (UNOS) transplant registry through 2005 and with the 2000 U.S. Census geographic data. Of the 35,346 subjects included in the analysis, 12% were waitlisted, 57% were black, 50% were men, 20% were impoverished, 45% had diabetes as the primary etiology of ESRD, and 73% had two or more comorbidities. The median distance from patient residence to the nearest transplant center was 48 mi. After controlling for multiple covariates, distance from patient residence to transplant center did not predict placement on the transplant waitlist. In contrast, race, neighborhood poverty, gender, age, diabetes, hypertension, body mass index, albumin, and the use of erythropoietin at dialysis initiation was associated with waitlisting. As neighborhood poverty increased, the likelihood of waitlisting decreased for blacks compared with whites in each poverty category; in the poorest neighborhoods, blacks were 57% less likely to be waitlisted than whites. This study suggests that improving the allocation of kidneys may require a focus on poor communities.

JAIDS Journal of Acquired Immune Deficiency Syndromes, 2013

Objectives-To evaluate the impact of family planning promotion on incident pregnancy in a combine... more Objectives-To evaluate the impact of family planning promotion on incident pregnancy in a combined effort to address Prongs 1 and 2 of Prevention of Mother-to-Child Transmission of HIV. Design-We conducted a factorial randomized controlled trial of two video-based interventions. Methods-"Methods-focused" and "Motivational" messages promoted long-term contraceptive use among 1060 couples with HIV in Lusaka, Zambia.

International Journal of Epidemiology, 1995

Background. One of the epidemiologist's most basic tasks Is estimation of disease occurrence. To ... more Background. One of the epidemiologist's most basic tasks Is estimation of disease occurrence. To perform this task, the epidemiologist frequently models variability in disease occurrence using one of three distributions-the binomial, the Poisson or the exponential distribution. Although epidemiologists often use them and their properties appear in standard texts, we know of no text or review that compares and contrasts epidemiological application of these distributions. Methods. In this commentary, we discuss these three basic distributions. We note key assumptions as well as limitations, and compare results from analyses based on each distribution. Results and Conclusions. We Illustrate that the three distributions, although superficially different, often lead to similar results. We argue that epidemiologists should often obtain similar results regardless of which distribution they use. We also point out that application of all three distributions can be inappropriate if assumptions of independence or homogeneity of risks fail to hold. Finally, we briefly review how these basic distributions can be used to justify use of other distributions, such as the Gaussian distribution, for studying disease-exposure associations.

International Journal for Quality in Health Care, 2003

Objectives. Clinical practice guidelines based on the results of randomized clinical trials recom... more Objectives. Clinical practice guidelines based on the results of randomized clinical trials recommend that patients with heart failure due to left ventricular systolic dysfunction (LVSD) be treated with angiotensin-converting enzyme inhibitors (ACEI) at doses shown to reduce mortality and readmission. This study examined the relationship between ACEI use at discharge and readmission among patients with heart failure due to LVSD. Methods and results. Data were abstracted from the medical records of 2943 randomly selected patients hospitalized for heart failure in 50 hospitals. The outcome of interest was the number of readmissions occurring up to 21 months after discharge. Sixhundred and eleven patients were eligible for analysis. Compared with patients discharged at a recommended ACEI dose, patients not prescribed an ACEI at discharge had an adjusted rate ratio of readmission (RR) of 1.74 [95% conWdence interval (CI) 1.22-2.48], while patients prescribed an ACEI at less than a recommended dose had an RR of 1.24 (95% CI 0.91-1.69) (P = 0.005 for the trend). Conclusion. Our results show that ACEI use at discharge in patients with LVSD is associated with decreased rate of readmission. These Wndings suggest that compliance with the ACEI prescribing recommendations listed in clinical practice guidelines for patients with heart failure due to LVSD confers beneWt.

Environmental Health Perspectives, 2006

Table 1 lists the study areas, types of facilities, potential exposure pathways, and contaminants... more Table 1 lists the study areas, types of facilities, potential exposure pathways, and contaminants of concern. All six studies were approved by the Centers for Disease Control and Prevention Institutional Review Board. Study participants in all areas gave informed consent before participating. Four additional cross-sectional studies conducted by ATSDR during this time period were not included in this analysis because they did not include comparison populations (ATSDR 1995a, 1996a) or did not use questionnaires similar to those used in the other studies (ATSDR 1994b, 1995c).

Diabetes Care, 2002

A randomized study Placebo Low dose High dose n 6 6 6 Fasting plasma glucose (mmol/l) 8.2 Ϯ 0.2 8... more A randomized study Placebo Low dose High dose n 6 6 6 Fasting plasma glucose (mmol/l) 8.2 Ϯ 0.2 8.8 Ϯ 0.4 8.3 Ϯ 0.6 8.4 Ϯ 0.3 8.4 Ϯ 1.1 7.2 Ϯ 0.4* Fasting plasma insulin (pmol/l) 8.7 Ϯ 1.7 8.3 Ϯ 1.6 13.4 Ϯ 2.5 8.7 Ϯ 1.2 9.0 Ϯ 1.8 13.2 Ϯ 2.5 Total cholesterol (mmol/l) 5.69 Ϯ 0.23 6.05 Ϯ 0.31 4.97 Ϯ 0.21 5.66 Ϯ 0.31 5.68 Ϯ 0.34 4.45 Ϯ 0.18* LDL cholesterol (mmol/l) 3.72 Ϯ 0.23 4.11 Ϯ 0.28 3.12 Ϯ 0.16 3.78 Ϯ 0.41 3.80 Ϯ 0.28 2.72 Ϯ 0.16* HDL cholesterol (mmol/l) 1.40 Ϯ 0.10 1.27 Ϯ 0.10 1.16 Ϯ 0.05 1.42 Ϯ 0.16 1.16 Ϯ 0.10 1.11 Ϯ 0.05 Triglycerides (mmol/l) 1.26 Ϯ 0.15 1.45 Ϯ 0.35 1.52 Ϯ 0.19 1.37 Ϯ 0.30 1.61 Ϯ 0.30 1.33 Ϯ 0.13 HbA 1c (%) 7.0 Ϯ 0.3 7.3 Ϯ 0.4 7.1 Ϯ 0.3 7.0 Ϯ 0.2 7.3 Ϯ 0.4 6.8 Ϯ 0.3 Blood pressure (mmHg) 134 Ϯ 13

Clinical Infectious Diseases, 2012

Background. In the United States, considerable geographic variation in the rates of culture-confi... more Background. In the United States, considerable geographic variation in the rates of culture-confirmed Campylobacter infection has been consistently observed among sites participating in the Foodborne Diseases Active Surveillance Network (FoodNet). Methods. We used data from the FoodNet Population Surveys and a FoodNet case-control study of sporadic infection to examine whether differences in medical care seeking, medical practices, or risk factors contributed to geographic variation in incidence. Results. We found differences across the FoodNet sites in the proportion of persons seeking medical care for an acute campylobacteriosis-like illness (range, 24.9%-43.5%) and in the proportion of ill persons who submitted a stool sample (range, 18.6%-40.7%), but these differences were not statistically significant. We found no evidence of geographic effect modification of previously identified risk factors for campylobacteriosis in the case-control study analysis. The prevalence of some exposures varied among control subjects in the FoodNet sites, including the proportion of controls reporting eating chicken at a commercial eating establishment (18.2%-46.1%); contact with animal stool (8.9%-30.9%); drinking water from a lake, river, or stream (0%-5.1%); and contact with a farm animal (2.1%-12.7%). However, these differences do not fully explain the geographic variation in campylobacteriosis. Conclusions. Future studies that quantify Campylobacter contamination in poultry or variation in host immunity may be useful in identifying sources of this geographic variation in incidence.

Clinical Chemistry, 2007

Background: Atrial fibrillation (AF) has been associated with myocardial oxidative stress, and an... more Background: Atrial fibrillation (AF) has been associated with myocardial oxidative stress, and antioxidant agents have demonstrated antiarrhythmic benefit in humans. We compared serum markers of oxidation and associated inflammation in individuals with or without AF. Methods: Serum markers of oxidative stress and inflammation were compared in a cross-sectional, case-control design study of 40 male individuals, with or without persistent or permanent AF, who were matched for age, sex, diabetes, and smoking status, known confounding variables for the measurement of oxidative stress. We used derivatives of reactive oxidative metabolites (DROMs) and ratios of oxidized to reduced glutathione (Eh GSH) and cysteine (Eh CySH) to quantify oxidative stress. We also measured inflammatory markers, including high-sensitivity C-reactive protein, interleukins 1β and 6, and tumor necrosis factor α. Results: Univariate, conditional logistical regression analysis showed that oxidative stress but not ...