مقایسهٔ روش‌ها

	Standardized Mortality Ratio	Direct Standardization
حوزه	جمعیت‌شناسی	جمعیت‌شناسی
خانواده	Process / pipeline	Process / pipeline
سال پیدایش	1987	2001
پدیدآور	Classical vital-statistics method (formalized by Breslow & Day)	Classical demographic method (formalized by Preston, Heuveline & Guillot)
نوع	Ratio of observed to expected deaths under a standard rate schedule	Rate adjustment by reweighting to a standard population
منبع بنیادین	Preston, S. H., Heuveline, P., & Guillot, M. (2001). Demography: Measuring and Modeling Population Processes. Blackwell. ISBN: 9781557864512	Preston, S. H., Heuveline, P., & Guillot, M. (2001). Demography: Measuring and Modeling Population Processes. Blackwell. ISBN: 9781557864512
نام‌های دیگر	SMR, Standardised Mortality Ratio, Indirectly Standardized Mortality Ratio	Directly standardized rate, Age-standardized rate, Direct method of standardization, Doğrudan Standardizasyon
مرتبط	4	4
خلاصه	The standardized mortality ratio (SMR) compares the number of deaths actually observed in a study population with the number that would be expected if that population had experienced a standard set of age-specific death rates. It is the central output of indirect standardization: a single ratio, usually multiplied by 100, that says whether a group's mortality is higher or lower than a reference after accounting for its age structure. Because it needs only the study group's age distribution and total deaths — not stable age-specific rates within the group — the SMR is the method of choice when the group is small or its age-specific deaths are sparse.	Direct standardization is a demographic technique that makes summary rates comparable across populations by applying each population's group-specific rates — most often age-specific death or disease rates — to a single, common standard population structure. The resulting directly standardized rate answers a counterfactual question: what would the crude rate be if every population had the same age (or other) composition? It removes the confounding effect of differing population structure so that genuine differences in underlying risk can be compared on a level footing.