Przegla̧d epidemiologiczny
-
Problems with sample selection in epidemiological studies starts with the definition of representativeness of the sample. The definition of representativeness as a "miniature of the population" is impractical, especially for very rare disease, and not suitable for certain types of epidemiological studies. ⋯ The article reviews different meanings of representativeness used directly or implicitly in epidemiological and statistical studies and gives examples of certain methods of sample selection for the specific purposes including matching in design. Some important sources of selection bias and methods of avoiding it are also addressed in this article.
-
Pseudomembranous colitis (PMC), antibiotic-associated diarrhoea (AAD), and colitis (AAC) caused by Clostridium difficile are recognized as complications of antibiotic treatment (cephalosporins, penicillins, clindamycin and others). Two groups are particularly at risk: older and immunocompromised patients. ⋯ To understand the epidemiology of the C. difficile infection, many outbreaks have been investigated by various methods. In the paper we reviewed different methods of C. difficile typing and discussed the epidemiology of C. difficile-associated infections in light of recent publications.