There is little evidence to indicate there is value in routine blood tests in asymptomatic patients; instead, this practice is more likely to produce false positive results that may lead to additional unnecessary testing. The decision to perform screening tests, and the selection of which tests to perform, should be done with careful consideration of the patient’s age, sex and any possible risk factors.
Sources:
Allan GM, Morros MP, Young J. Subclinical hypothyroidism and TSH screening. Can Fam Physician. 2020;66(3):188. PMID: 32165467.
Allan M, Young J. CFPCLearn. CBC (Confusing Broad Check) for Screening?. May 15, 2017.
Boland BJ, et al. Yield of laboratory tests for case-finding in the ambulatory general medical examination. Am J Med. 1996 Aug;101(2):142-52. PMID: 8757353.
Related Resources:
Patient Pamphlet: Health Check-ups: When you need them and when you don’t
College of Family Physicians of Canada Infographic: Rethinking the Annual Physical Exam and Screening Tests
Dr. Mike Evans Video: Do More Screening Tests Lead to Better Health?