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Which study type is that? A guide to study types

Study and experiment types for Health Sciences and Medicine

Observational Studies

Observational studies

An observational study is a type of research design used to gather information about individuals or populations without manipulating the environment or variables. In these studies, researchers observe and collect data on subjects as they naturally occur in their usual settings.

 

Searching for observational studies


Adding another search line with keywords or phrases directly related to a study type will help narrow results and is one way of finding the study type you are interested in.
 

Some of the keywords related to observational studies might include, but are not limited to the following:

  • observational - cohort - prospective -  retrospective - case report - case-control - cross-sectional -  longitudinal

Example:

  • hypertension AND cross-sectional
  • obesity AND case-control

 

 

 

Subject headings are standard descriptions used by databases to help with searching. They will differ across databases but help to retrieve articles on a topic, even if different words are used in the text.

Subject headings should be investigated within each database but some examples for observational studies may include:
 

  • Medline (Ovid) - Epidemiologic Studies/ -  Case‐Control Studies/ or Cohort Studies/ or Cross‐Sectional Studies/ - Observational Studies as Topic/ - Clinical Studies as Topic/ - single-case studies as topic/ - case reports as topic/
     
  • Embase (Ovid) - observational study/ - cohort analysis/ - cross‐sectional study/ - case study/ - longitudinal study/ - retrospective study/ - prospective study/ - exp case control study/
     
  • CINAHL -  (MH "Nonexperimental Studies+") - (MH "Correlational Studies") - (MH "Epidemiological Research")

Learn more about Subject Headings

 

 

 

Some databases include advanced search options that allow you to limit your results to certain study or publication types. 

  • Medline (Ovid):
    Additional Limits > Publication Types > Observational Study 
    Additional Limits > Publication Types > Case Reports
     
  • PsycInfo (Ovid)
    Additional Limits > Methodology > Select from options
 

 

Search filters are pre-made search strategies designed to retrieve specific results from databases including different study types. They can sometimes be very complex multi-line searches that you can add to your existing search strategy and then combine with AND.

Careful consideration is required when using search filters to ensure they meet specific needs.
 

  • BMJ Best Practice Study Design Search Filters for Ovid Databases Link
     
  • ISSG Filters for Observational Studies Link
     
  • Observational Studies - MEDLINE. In: Canada's Drug Agency Search Filters Database. Ottawa: Canada's Drug Agency; 2025 Link
      

Further resources for observational studies

  • Rosenbaum, P. R., Rosenbaum, P., & Briskman. (2010). Design of observational studies (Vol. 10, pp. 978-1). New York: Springer. Catalogue Link
     
  • Hackshaw, A. (2015). A concise guide to observational studies in healthcare. John Wiley & Sons. Catalogue Link

 

 

 


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