Year: 2026
Type: book-chapter
Abstract: Introduction: Cohort studies are among the most robust analytical observational designs for assessing the association between an exposure and the occurrence of an outcome.Their main strength lies in establishing the temporal sequence between these two events, allowing for the estimation of incidences and the quantification of risks using measures such as relative risk (RR), incidence rate, and hazard ratio (HR).Development: This chapter describes the methodological foundations of prospective, retrospective, and ambispective cohorts, emphasizing the importance of appropriate population selection, precise definition of the exposure and outcomes, longitudinal follow-up, and control for confounding factors.It addresses the main measures of frequency and association, including cumulative incidence, incidence rate, attributable risk, RR, and HR, complemented by survival analysis tools such as Kaplan-Meier curves and Cox regression.Criteria for evaluating the internal and external validity and clinical relevance of the findings are also highlighted.Conclusions: Cohort studies provide fundamental evidence for understanding the natural history of diseases and estimating the impact of risk and protective factors.Their proper interpretation requires assessing the time frame, the quality of follow-up, the control of confounding factors, and the true magnitude of the observed effects.Beyond statistical results, these studies allow for the translation of evidence into clinical decisions and public health strategies aimed at prevention and improving healthcare.
Language: Spanish
Subfield: Statistics and Probability
Field: Mathematics
Domain: Physical Sciences
Open Access status: gold
OpenAlex ID: W7214955822