Generalizing and transporting inferences about the effects of treatment assignment subject to non-adherence

We discuss the identifiability of causal estimands for generalizability and transportability analyses, both under perfect and imperfect adherence to treatment assignment. We consider a setting where the trial data contain information on baseline covariates, assignment at baseline, intervention at baseline (point treatment), and outcomes; and where the data from non-randomized individuals only contain information on baseline covariates. In this setting, we review identification results under perfect adherence and study two examples in which non-adherence severely limits the ability to transport inferences about the effects of treatment assignment to the target population. In the first example, trial participation has a direct effect on treatment receipt and, through treatment receipt, on the outcome (a "trial engagement effect" via adherence). In the second example, participation in the trial has unmeasured common causes with treatment receipt. In both examples, the effect of assignment on the outcome in the target population is not identifiable. In the first example, however, the effect of joint interventions to scale-up trial activities that affect adherence and assign treatment is identifiable. We conclude that generalizability and transportability analyses should consider trial engagement effects via adherence and selection for participation on the basis of unmeasured factors that influence adherence

Prevalence, serological typing and pcr sensitivity comparision of salmonella typhimurium, salmonella enteritidis and salmonella spp. isolated from raw chicken carcasses

Poultry meat is the most popular food products worldwide. Salmonella are important foodborne pathogens especially in poultry. Objectives in this study were to determine the presence of Salmonella spp. and to detect the incidence of Salmonella Typhimurium and Salmonella Enteritidis in 100 raw chicken carcasses. Carcasses which were collected from Istanbul (n = 100) for the detection of the organism by conventional culture method and confirmed of strains by PCR of DNA using invA and fliC genes. According to the results, Salmonella spp. was determined in 15 (15%) raw chicken carcass samples of 100 total samples analyzed due to both PCR and conventional culture method include serological tests; Four (26.6%) samples were identified as S. Enteritidis while 3 (20%) samples were S. Typhimurium of 15 total Salmonella spp. Sensitivity of PCR procedures for Salmonella spp. and S. Typhimurium were high and quite specific. However, the sensitivity of the mentioned procedure was very low for S. Enteritidis. It is being thought that PCR procedures can be good alternative methods to microbiological analysis procedures for Salmonella spp. and S. Typhimurium while microbiological analysis procedures have more advantages than PCR procedures for protection of the public health at the detection of S. Enteritidis