UPDATED: July 21, 2025.   Original Post: May 27, 2019

True or false: Healthcare literature that is more than five years old has no value.
Answer: It depends.

Healthcare professionals seeking answers to clinical questions for patient care need the most current available evidence. This type of medical information is continually evolving. For example, drug information can become outdated – and possibly outright dangerous – in as little as a year or two.

Other types of healthcare information change less frequently. Older anatomy and physiology textbooks and atlases, for example, may still include accurate information but may lack diverse representation and accessibility features found in newer editions.

Sometimes, older medical literature is valuable because of its historical perspective. One current example is case studies of past public health efforts to eradicate infectious diseases that are now resurging, such as measles. Lessons from past immunization campaigns, both successful and unsuccessful, can inform current and future strategies (Infante, 2025). They can provide insights such as (Hebert, 2012; Eddy, 2023; Infante, 2025):

  • The vaccination coverage rate needed for herd immunity.
  • The roles that socioeconomical, political, and cultural factors play.
  • Approaches to help overcome challenges and barriers such as vaccine hesitancy and misinformation.

Other examples of historical medical information that still has merit include:

  • Literature that illustrates the evolution of current medical knowledge and practices, and healthcare policies.
  • Literature that involves practices that have withstood the test of time and are still relevant (e.g., hirudotherapy).

Where to find the most current clinical information

Where to find older medical literature

  • PubMed can retrieve citations going back to the early 20th century for some publications.
  • PsychINFO® contains historical psychological abstracts dating back to the 1800s.
  • Library Services’ Ovid® journals collection contains titles dating back to 1946.

Older back issues of many journals can also be found by:

If you’re unsure of where to find the information you need, current or historical reach out to Library Services at AskLibrary@nshealth.ca or book a consultation with a library team member.

References:

1. Infante, D. (2025). Immunization strategies: What lessons can we learn from successful campaigns? News-Medical.Net. https://www.news-medical.net/health/Immunization-strategies-What-lessons-can-we-learn-from-successful-campaigns.aspx

2. Eddy, J.J., Smith, H.A., & Abrams, J.E. (2023). Historical lessons on vaccine hesitancy: Smallpox, polio, and measles, and implications for COVID-19. Perspectives in Biology and Medicine, 66(1), 145-159. doi: 10.1353/pbm.2023.0008

3. Hebert, C.J., Hall, C.M., & Odoms, L.N.J. (2012). Lessons learned and applied. Human vaccines & immunotherapeutics, 8(5), 560-568. doi: 10.4161/hv.19204

Lana MacEachern

Library Technician
Pictou/Colchester-East Hants/Cumberland Region