방법 비교

	다기간 역확률 가중치 (Multi-period Inverse Probability Weighting)	역확률 가중치 (Inverse Probability Weighting, IPW / IPTW)
분야	인과추론	인과추론
계열	Regression model	Regression model
기원 연도	2000	2000
창시자	Robins, Hernan & Brumback	Robins, Hernán & Brumback
유형	Weighted causal estimator	Causal inference weighting estimator
원전	Robins, J. M., Hernan, M. A., & Brumback, B. (2000). Marginal structural models and causal inference in epidemiology. Epidemiology, 11(5), 550-560.	Robins, J. M., Hernán, M. A., & Brumback, B. (2000). Marginal Structural Models and Causal Inference in Epidemiology. Epidemiology, 11(5), 550-560.
별칭	longitudinal IPW, multi-period IPW, time-varying IPW, sequential IPW	IPW, IPTW, inverse probability of treatment weighting, marginal structural model weighting
관련	6	5
요약	Multi-period Inverse Probability Weighting (IPW) estimates the causal effect of a treatment that varies across multiple time periods by reweighting observations according to the probability of receiving each period's treatment given past treatment history and time-varying confounders. It creates a pseudo-population where treatment at each period is independent of measured confounders, enabling unbiased estimation of sustained treatment strategies.	Inverse Probability Weighting is a causal-inference method that assigns each observation a weight equal to the inverse of its probability of receiving the treatment it actually received. Introduced by Robins, Hernán and Brumback (2000) for marginal structural models, it builds a pseudo-population in which treatment is independent of measured confounders, balancing selection bias.