مقایسهٔ روش‌ها

	مطالعه کوهورت	تحلیل فراتحلیل دوز-پاسخ
حوزه	اپیدمیولوژی	ترکیب شواهد
خانواده	Process / pipeline	Process / pipeline
سال پیدایش	Mid-20th century (formal epidemiological design codified ~1950s)	1992
پدیدآور	Doll & Hill (British Doctors Study, 1951); Snow (cholera, 1854)	Greenland & Longnecker (1992), Advanced by Orsini et al. (2012)
نوع	Observational longitudinal study design	Method
منبع بنیادین	Rothman, K. J., Greenland, S., & Lash, T. L. (2008). Modern Epidemiology (3rd ed.). Lippincott Williams & Wilkins. ISBN: 978-0781755641	Greenland, S., & Longnecker, M. P. (1992). Methods for trend estimation of environmental health risks, with application to exposure to contaminated groundwater. Statistics in Medicine, 11(14‐15), 1837–1847.
نام‌های دیگر	longitudinal study, follow-up study, panel study, incidence study	Dose-Response Relationship, Non-Linear Meta-Analysis, Dose-Effect Synthesis
مرتبط	6	1
خلاصه	A cohort study assembles a group of individuals who share a common starting point — typically freedom from the outcome of interest — and follows them over time to observe who develops the outcome. By comparing incidence rates between exposed and unexposed subgroups, researchers can estimate relative risk and absolute risk differences. Cohort studies are the gold-standard observational design for measuring disease incidence and establishing temporal relationships between exposure and outcome.	Dose-response meta-analysis is a specialized evidence synthesis method that models the relationship between exposure dose (or intensity, duration, quantity) and health outcome across multiple studies, assessing whether effects follow a linear trend, nonlinear curve, or threshold pattern. Pioneered by Greenland and Longnecker (1992) and refined by Orsini et al. (2012), dose-response meta-analysis answers critical questions like 'Does cardiovascular disease risk increase consistently with salt intake, or is there a threshold above which risk plateaus?' and 'Does the benefit of physical activity increase linearly with exercise duration, or do diminishing returns occur at high doses?' This method is essential for risk assessment, policy-setting on safe exposure limits, and optimizing treatment dosing.