Learn More
Despite the growing popularity of propensity score (PS) methods in epidemiology, relatively little has been written in the epidemiologic literature about the problem of variable selection for PS models. The authors present the results of two simulation studies designed to help epidemiologists gain insight into the variable selection problem in a PS(More)
Genome-wide association studies have reported an association between the A-allele of rs1006737 within CACNA1C and affective disorders and schizophrenia. The aim of the present study was to investigate the relationship between rs1006737 and established and potential endophenotypes for these disorders in a population-based cohort of 3793 subjects, using an(More)
OBJECTIVE We aimed to investigate the association between nocturnal sleep duration, changes in nocturnal sleep duration and cognitive impairment in older adults. METHODS 4010 participants of a population-based cohort study provided information on nocturnal sleep duration at baseline (1991-1995) and at follow-up (2002/2003). 792 follow-up participants aged(More)
BACKGROUND Although osteoarthritis (OA) is thought to derive from defective chondrocyte metabolism and thus inherently lack the large scale systemic response of rheumatoid arthritis, there is increasing interest in the acute phase proteins in OA. OBJECTIVE To assess the association between high sensitivity C reactive protein (hsCRP) and severity and(More)
Confounding can be a major source of bias in nonexperimental research. The authors recently introduced propensity score calibration (PSC), which combines propensity scores and regression calibration to address confounding by variables unobserved in the main study by using variables observed in a validation study. Here, the authors assess the performance of(More)
OBJECTIVE To add to the evidence on comparative long-term effects of insulin analog glargine versus human NPH insulin on the risk for cancer. RESEARCH DESIGN AND METHODS We identified cohorts of initiators of glargine and human NPH without an insulin prescription during the prior 19 months among patients covered by the Inovalon Medical Outcomes Research(More)
Early diagnosis is a tenet in oncology and should enable early treatment with the expectation of improved outcome. Extent and determinants of patient delay of diagnosis in breast cancer patients and its impact on stage of disease were examined in a population based study among female breast cancer patients in Germany. Two hundred and eighty-seven women,(More)
Comparative effectiveness research includes cohort studies and registries of interventions. When investigators design such studies, how important is it to follow patients from the day they initiated treatment with the study interventions? Our article considers this question and related issues to start a dialogue on the value of the incident user design in(More)
CONTEXT There has been rapid adoption of newer radiation treatments such as intensity-modulated radiation therapy (IMRT) and proton therapy despite greater cost and limited demonstrated benefit compared with previous technologies. OBJECTIVE To determine the comparative morbidity and disease control of IMRT, proton therapy, and conformal radiation therapy(More)
OBJECTIVE To study the relation between measures of personality and risk of cardiovascular disease and cancer in a large cohort. DESIGN Follow-up of population based cohort. SETTING Heidelberg, Germany. PARTICIPANTS 5114 women and men aged 40-65 in 1992-5. MAIN OUTCOME MEASURES Psychological traits assessed by several standardised personality(More)