Research and publish. Part 5. How to present and evaluate an observational study: cohorts

Authors

DOI:

https://doi.org/10.22516/25007440.1351

Keywords:

Cohort, Epidemiology, Observational studies, Relative risk, Validity (epidemiology), Evidence-based medicine

Abstract

Introduction: Cohort studies are a fundamental design in epidemiological and clinical research, allowing the evaluation of associations between exposures and health outcomes over time. Their longitudinal structure enables the estimation of disease incidence and the calculation of association measures such as relative risk. However, these studies present methodological challenges, including selection bias, information bias, and confounding, which must be addressed through appropriate design and analytical strategies.

Methods: To enhance the quality and transparency in reporting cohort studies, the STROBE Statement provides a detailed guide on key aspects to include in a scientific article, such as participant selection, exposure and outcome measurement, and statistical methods used.

Results: In the interpretation of cohort studies, the JAMA Evidence framework facilitates the assessment of study validity through a three-step approach: identification of bias risk, analysis of the magnitude and precision of the association, and determination of the applicability of findings in clinical practice.

Conclusion: Cohort studies are essential for generating health-related evidence, but their validity relies on rigorous execution and proper critical appraisal. The use of tools such as STROBE and JAMA Evidence improves the quality of reporting and interpretation, strengthening their impact on biomedical research and clinical practice.

Downloads

Download data is not yet available.

Author Biography

Juan Jose Yepes Nuñez, Universidad de los Andes

Clinical allergist, MSc in Clinical Sciences (Clinical Epidemiology). PhD in Health Research Methodology with emphasis in Clinical Epidemiology. Assistant Professor and Director of Postgraduate Studies in Epidemiology, School of Medicine, Universidad de los Andes. Institutional Specialist, Pneumology Section, Hospital Universitario Fundación Santa Fe. Bogotá, Colombia.

References

Gordis L. Epidemiology. Elsevier; 2013.

Hulley SB, Cummings SR, Browner WS, Grady DG, Newman TB. Designing Clinical Research. 4.a edición. Filadelfia: Lippincott Williams & Wilkins; 2013.

Kannel WB. CHD risk factors: a Framingham study update. Hosp Pract (Off Ed). 1990;25(7):119-27, 30. https://doi.org/10.1080/21548331.1990.11703974

Yoshimoto Y, Kato H, Schull WJ. A review of forty-five years study of Hiroshima and Nagasaki atomic bomb survivors. Cancer risk among in utero-exposed survivors. J Radiat Res. 1991;32 Suppl:231-8. https://doi.org/10.1269/jrr.32.SUPPLEMENT_231

Colditz GA, Hankinson SE. The Nurses’ Health Study: lifestyle and health among women. Nat Rev Cancer. 2005;5(5):388-96. https://doi.org/10.1038/nrc1608

von Elm E, Altman DG, Egger M, Pocock SJ, Gotzsche PC, Vandenbroucke JP, et al. The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement: guidelines for reporting observational studies. Ann Intern Med. 2007;147(8):573-7. https://doi.org/10.7326/0003-4819-147-8-200710160-00010

Levine M, Ioannidis JPA, Haines AT, Guyatt G. Harm (Observational Studies). En: Guyatt G, Rennie D, Meade MO, Cook DJ (editores). Users’ Guides to the Medical Literature: A Manual for Evidence-Based Clinical Practice. 3.a edición. McGraw Hill; 2015. p. 538-561.

Table 1. Advantages and disadvantages of cohort studies

Published

2025-04-12

How to Cite

Yepes Nuñez, J. J. (2025). Research and publish. Part 5. How to present and evaluate an observational study: cohorts. Revista Colombiana De Gastroenterología, 40(1), 52–56. https://doi.org/10.22516/25007440.1351

Issue

Section

Review articles