Purpose: With observational epidemiologic studies, there is often concern that an unmeasured variable might confound an observed association. Investigators can assess the impact from such unmeasured variables on an observed relative risk (RR) by utilizing externally sourced information and applying an indirect adjustment procedure, for example, the "Axelson adjustment." Although simple and easy to use, this approach applies to exposure and confounder variables that are binary. Other approaches eschew specific values and provide only bounds on the potential bias.
Methods: For both multiplicative and additive RR models, we present formulae for indirect adjustment of observed RRs for unmeasured potential confounding variables when there are multiple categories. In addition, we suggest an alternative strategy to identify the characteristics that the confounder must have to explain fully the observed association.
Results And Conclusions: We provide examples involving studies of pediatric computer tomography scanning and leukemia and nuclear radiation workers and smoking to demonstrate that with externally sourced information, an investigator can assess whether confounding from unmeasured factors is likely to occur.
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http://dx.doi.org/10.1016/j.annepidem.2018.09.003 | DOI Listing |
Front Psychol
December 2024
Key Laboratory of Xinjiang Endemic and Ethnic Diseases of the Ministry of Education, Department of Public Health, Shihezi University School of Medicine, Xinjiang, China.
Background: Adolescents who suffer from school bullying are often accompanied by problems such as sleep disorders and depression. However, it remains unclear how depressive symptoms and sleep assessments such as sleep duration interact in the specific mechanisms of exposure to school bullying.
Objective: To understand the role of sleep duration, depressive symptoms on school bullying in adolescents and the mediating role of sleep duration in this context.
BMC Pregnancy Childbirth
December 2024
Center for International Health, LMU, Munich, Germany.
Background: Despite recent improvements in the overall health status of Nepal's population, newborn morbidities and mortalities have remained a challenge. This study explores the situation and care strategies for newborn health problems in the Gandaki Province of Nepal.
Methods: This is a retrospective hospital records analysis.
Clin Nutr ESPEN
December 2024
Rehabilitation Department, Kunshan Rehabilitation Hospital, 888 Yingbin East Road, Kunshan 215314, China; Shanghai University of Medicine and Health Sciences, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Shanghai, China201203. Electronic address:
Background And Aims: Dysphagia is significantly correlated with prognostic outcomes in patients with stroke; however, the intrinsic mechanism of action between the two remains unclear. This study aimed to model the intrinsic mechanism of action between dysphagia and prognostic outcomes in patients with stroke based on structural equation modeling.
Methods: A retrospective analysis of 900 inpatients with stroke from three large hospitals was performed.
J Infect
December 2024
Microbiome Medicine Centre, Department of Laboratory Medicine, ZhuJiang Hospital, Southern Medical University, Guangzhou, Guangdong, China.
Background: Ureaplasma parvum (U. parvum) is generally regarded as innocuous, and studies focusing on variations in pathogenicity among U. parvum serovars are inadequate.
View Article and Find Full Text PDFJ Thorac Oncol
December 2024
Moores Cancer Center, University of California San Diego, La Jolla, CA 92037, USA; Department of Medicine, University of California San Diego, La Jolla, CA 92037, USA; Department of Thoracic/Head and Neck Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA.
Introduction: Copy-number (CN) loss of chromosome 9p, or parts thereof, impair immune response and confer ICT resistance by direct elimination of immune-regulatory genes on this arm, notably IFNγ genes at 9p24.1, and type-I interferon (IFN-I) genes at 9p21.3.
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