title: A practitioner's guide to developing critical appraisal skills: observational studies.
abstract: BACKGROUND
  and Overview. Observational investigations provide an opportunity to document the distribution of diseases in various populations and to explore correlations between exposures and outcomes. Interpreting such correlations as causal is challenging and can lead to more harm than good when used as a basis for advising lifestyle changes or interventions to healthy people. The aim of this review is to provide a brief introduction to observational study designs and describe some of their strengths and weaknesses.
  
  
  CONCLUSIONS
  Observational findings can be useful to guide clinical research, but often they do not provide a reliable basis for clinical decision making. Caution in applying observational findings to clinical practice is particularly important when caring for healthy people.
authors: Department of Dental Clinical Sciences, Faculty of Dentistry, Dalhousie University, 5981 University Ave., P.O. Box 15000, Halifax, Nova Scotia B3H 4R2, Canada. dmatthew@dal.ca
authors: Debora C
authors: DC
authors: Matthews
authors: Philippe P
authors: PP
authors: Hujoel
mesh_terms: D015982:Bias; D015984:Causality; D003657:Decision Making; D018865:Dental Research / Q000379:methods*; D006801:Humans; D019370:Observation / Q000379:methods*; D012107:Research Design