Cohort Studies

  • Bryan Kestenbaum


  1. 6.1
    Cohort studies are observational studies that are conducted in three fundamental steps:
    1. 6.1.1

      Exclude people who have the disease outcome at the start of the study

    2. 6.1.2

      Measure one or more exposures to define the cohorts

    3. 6.1.3

      Determine the incidence of the disease outcome over time 

  2. 6.2

    Ideal measurements of the exposure should be accurate, precise, equitable, and timely.

  3. 6.3

    Pharmacoepidemiology studies are observational studies that evaluate the consequences of medications or procedures.

  4. 6.4
    Analysis of cohort study data
    1. 6.4.1

      Relative risk is a ratio of disease incidences that describes risk to an individual.

    2. 6.4.2

      Attributable risk and population attributable risk are differences in disease incidences that describe risk to a population.

  5. 6.5
    Advantages of cohort studies include:
    1. 6.5.1

      Can discern temporal relationships between exposures and disease

    2. 6.5.2

      Can be used to efficiently study multiple disease outcomes

  6. 6.6
    Limitations of cohort studies include:
    1. 6.6.1

      Confounding characteristics other than the exposure of interest may bias observed associations with disease

    2. 6.6.2

      Inefficient design for studying rare diseases or those with long latency periods



  1. 1.
    Kestenbaum B, Rudser KD, de Boer IH, et al. Differences in kidney function and incident hypertension: the multi-ethnic study of atherosclerosis. Ann Intern Med. 2008;148(7):501–8.CrossRefGoogle Scholar
  2. 2.
    Bild DE, Bluemke DA, Burke GL, et al. Multi-Ethnic Study of Atherosclerosis: objectives and design. Am J Epidemiol. 2002;156(9):871–81.CrossRefGoogle Scholar
  3. 3.
    He K, Xun P, Brasky TM, Gammon MD, Stevens J, White E. Types of fish consumed and fish preparation methods in relation to pancreatic cancer incidence: the VITAL Cohort Study. Am J Epidemiol. 2013;177(2):152–60.CrossRefGoogle Scholar
  4. 4.
    Belanger CF, Hennekens CH, Rosner B, Speizer FE. The nurses’ health study. Am J Nurs. 1978;78(6):1039–40.PubMedGoogle Scholar
  5. 5.
    Avorn J. In defense of pharmacoepidemiology – embracing the yin and yang of drug research. N Engl J Med. 2007;357(22):2219–21.CrossRefGoogle Scholar
  6. 6.
    Hviid A, Melbye M, Pasternak B. Use of selective serotonin reuptake inhibitors during pregnancy and risk of autism. N Engl J Med. 2013;369(25):2406–15.CrossRefGoogle Scholar

Copyright information

© Springer Nature Switzerland AG 2019

Authors and Affiliations

  • Bryan Kestenbaum
    • 1
  1. 1.Division of Nephrology, Department of MedicineUniversity of WashingtonSeattleUSA

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