Over the past decade, an increasing number of observational studies have examined the effectiveness or safety of treatments for rheumatoid arthritis. Unlike randomized controlled trials (RCTs), ...

In their recent article in Journal of Clinical Oncology, Soni et al 1 compared findings from randomized controlled trials (RCTs) in oncology with analogous observational comparative effectiveness ...

Evidence is mounting that specific gut bacteria are linked to sleep conditions, which may open the doors to dietary ...

Outside the field of statistics, the literature on observational studies offers advice about research designs or strategies for judging whether or not an association is causal, such as multiple ...

After showing two groups of schoolteachers a videotape of an eight-year-old boy, psychologists John Santrock and Russel Tracy found that the teachers’ judgment of the child ultimately depended on ...

8 Center for Clinical Technology and Research of Joint Surgery, Hunan, China Correspondence to Dr Guanghua Lei, Department of Orthopaedics, Xiangya Hospital, Central South University, Changsha, Hunan, ...