Although cigarette smoking and alcohol consumption increase risk for head and neck cancers, there have been few attempts to model risks quantitatively and to formally evaluate cancer site-specific risks. The authors pooled data from 15 case-control studies and modeled the

The association between alcoholic liver disease (ALD) and tumor necrosis factor- gene (TNFA) polymorphisms has been analyzed in several studies, but results have been conflicting. The main purpose of this study was to integrate previous findings and explore whether these

According to the definition of confounding in a causal diagram, the association of body mass index (weight (kg)/height (m)2) with health-related outcomes is almost always noncausal, attributable to confounding by weight and perhaps height. The same conclusion holds for any

Causal inferences about the effect of an exposure on an outcome may be biased by errors in the measurement of either the exposure or the outcome. Measurement errors of exposure and outcome can be classified into 4 types: independent nondifferential,

Understanding the natural history of sexually transmitted infections requires the collection of data on sexual behavior. However, there is concern that self-reported information on sexual behavior may not be valid, especially if study participants are culturally and linguistically distinct. The

To evaluate the representativeness of controls in an ongoing, population-based, case-control study of birth defects in 10 centers across the United States, researchers compared 1997-2003 birth certificate data linked to selected controls (n = 6,681) and control participants (n =

Candidate gene association studies (CGAS) are a useful epidemiologic approach to drawing inferences about relations between genes and disease, especially when experimental data support the involvement of specific biochemical pathways. The value of CGAS is apparent when allele frequencies are

Genotypes of single nucleotide polymorphisms are subject to misclassification. If ignored, such misclassification can seriously distort the estimated genotype effects on the disease or outcome of interest. Validation data (gold standard or replicated surrogates) are required to assess the degree

Alpha-1-antitrypsin deficiency is a genetic condition associated with severe, early-onset chronic obstructive pulmonary disease (COPD). However, there is significant variability in lung function impairment among persons with the protease inhibitor ZZ genotype. Early identification of persons at highest risk of

Associations between stress hormones and preterm delivery have not been fully explored. In this study, pregnant women enrolled from 52 clinics in 5 Michigan communities (1998-2004) provided urine samples for 3 days (waking and bedtime) during midpregnancy. Urinary catecholamine levels

The authors examined the association of gestational hypertensive disorders (hypertension, preeclampsia, eclampsia) with adult cognitive function among men born in 1978-1983 in a well-defined geographic area of northern Denmark. Data from the Danish Medical Birth Registry, the Danish National Registry

Accumulating evidence suggests that inadequate vitamin D levels may predispose people to chronic diseases. The authors aimed to investigate whether serum 25-hydroxyvitamin D (25(OH)D) level predicts mortality from cardiovascular disease (CVD). The study was based on the Mini-Finland Health Survey

Persons with type 2 diabetes have a high risk of late-life cognitive impairment, and physical activity might be a potential target for modifying this risk. Therefore, the authors evaluated the association between physical activity level and cognition in women with

Multisymptom illness is more prevalent in 1991 Gulf War veterans than in military comparison groups; less is known about comorbidities. The authors compared physical, psychological, and functional comorbidities in Australian male Gulf War I veterans with those in actively (non-Gulf)

The authors performed a time-series analysis to test the association between air pollution and daily numbers of hospitalizations for headache in 7 Chilean urban centers during the period 2001-2005. Results were adjusted for day of the week and humidex. Three