{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,14]],"date-time":"2026-10-14T01:45:33Z","timestamp":1791942333522,"version":"4.3.4"},"reference-count":34,"publisher":"Wiley","issue":"23-24","license":[{"start":{"date-parts":[[2026,10,13]],"date-time":"2026-10-13T00:00:00Z","timestamp":1791849600000},"content-version":"vor","delay-in-days":12,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"},{"start":{"date-parts":[[2026,10,1]],"date-time":"2026-10-01T00:00:00Z","timestamp":1790812800000},"content-version":"tdm","delay-in-days":0,"URL":"http:\/\/doi.wiley.com\/10.1002\/tdm_license_1.1"}],"funder":[{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["12371281"],"award-info":[{"award-number":["12371281"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Statistics in Medicine"],"published-print":{"date-parts":[[2026,10]]},"abstract":"<jats:title>ABSTRACT<\/jats:title>\n                  <jats:p>This paper develops a covariate adjustment framework for randomized block  factorial experiments that accommodates high\u2010dimensional covariates and missing baseline measurements. We propose three Lasso\u2010based regression adjustment procedures. Under a randomization\u2010based finite\u2010population framework that allows model misspecification, we show that the resulting Lasso\u2010adjusted estimators are consistent and jointly asymptotically normal. We also provide Neyman\u2010type covariance estimators that support asymptotically valid conservative inference. For the first projection adjustment, the asymptotic variance of each factorial\u2010effect estimator is no larger than that of the corresponding unadjusted estimator. For the joint projection and stratum\u2010specific adjustments, the differences between the asymptotic covariance matrices of the unadjusted and adjusted estimators are positive semidefinite. We also study, within a design\u2010based framework, three strategies for handling missing covariates and provide practical guidance. Efficiency comparisons among these strategies require the linear spaces used in their sparse population projections to be nested. Under this nesting condition, when missingness indicators are informative about potential outcomes, incorporating them as additional adjustment variables can further improve efficiency. None of the three strategies requires specifying parametric outcome or missingness models. Inference is based on randomization and the stated regularity conditions. Single imputation and the missingness\u2010indicator method additionally require treatment\u2010invariant baseline missingness. Simulation studies and an empirical application corroborate the theoretical findings.<\/jats:p>","DOI":"10.1002\/sim.70761","type":"journal-article","created":{"date-parts":[[2026,10,14]],"date-time":"2026-10-14T01:03:07Z","timestamp":1791939787000},"update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Randomization\u2010Based Covariate Adjustment for Randomized Block 2K Factorial Experiments With Missing Baselines"],"prefix":"10.1002","volume":"45","author":[{"given":"Zixuan","family":"Zhao","sequence":"first","affiliation":[{"name":"School of Management Fudan University  Shanghai China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8321-6859","authenticated-orcid":false,"given":"Yuehan","family":"Yang","sequence":"additional","affiliation":[{"name":"School of Statistics and Mathematics Central University of Finance and Economics  Beijing China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2026,10,13]]},"reference":[{"issue":"1","key":"e_1_2_11_2_1","doi-asserted-by":"crossref","first-page":"13","DOI":"10.1200\/JCO.2014.57.0572","article-title":"Impact of the Addition of Carboplatin and\/or Bevacizumab to Neoadjuvant Once\u2010Per\u2010Week Paclitaxel Followed by Dose\u2010Dense Doxorubicin and Cyclophosphamide on Pathologic Complete Response Rates in Stage II to III Triple\u2010Negative Breast Cancer: CALGB 40603 (Alliance)","volume":"33","author":"Sikov W. 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