Standard methods for survival analysis, such as the time-dependent Cox model, may produce biased effect estimates when there exist time-dependent confounders that are themselves affected by previous treatment or exposure. Marginal structural models are a new class of causal models the parameters of which are estimated through inverse-probability-of-treatment weighting; these models allow for ap...

    Background: Aging is a major challenge not only for high-income countries but also for middle- and low-income countries. The length of stay (LOS) in hospitals is one of the major concerns of elderly patients, which should be taken into consideration. We aimed to investigate the factors affecting LOS of elderly patients admitted to a referral hospital of northeast of Iran.    Methods: A rel...

background: for xenograft models of triple-negative breast cancer (tnbc) to be valuable in development of molecularly-targeted drugs, careful characterization is essential to their validation. the present study aimed to validate the tnbc xenograft model with a specific focus on angiogenesis. methods : twelve tnbc xenograft tumors and 12 human breast cancer tumors (htnbc) were included in this s...

BACKGROUND Pollen information is indispensable for allergic individuals and clinicians. This study aimed to develop forecasting models for the total annual count of airborne pollen grains based on data monitored over the last 20 years at the Mie Chuo Medical Center, Tsu, Mie, Japan. METHODS Airborne pollen grains were collected using a Durham sampler. Total annual pollen count and pollen coun...

Critical research questions in the study of addictive behaviors concern how these behaviors change over time: either as the result of intervention or in naturalistic settings. The combination of count outcomes that are often strongly skewed with many zeroes (e.g., days using, number of total drinks, number of drinking consequences) with repeated assessments (e.g., longitudinal follow-up after i...

the mediterranean flour moth, ephestia kuehniella zeller, is one of the major pests in stored products worldwide. several problems assossiated with the use of conventional insecticides have strongly demonstrated the need for applying alternative safe compounds such as insect growth regulators (igrs). in the present study, growth regulating activity and hematological effects of pyriproxifen and ...