Planning a method for covariate adjustment in individually randomised trials: a practical guide
Open accessAbstract
Background: It has long been advised to account for baseline covariates in the analysis of confirmatory randomised trials, with the main statistical justifications being that this increases power and, when a randomisation scheme balanced covariates, permits a valid estimate of experimental error. There are various methods available to account for covariates but it is not clear how to choose among them. Methods: Taking the perspective of writing a statistical analysis plan, we consider how to choose between the three most promising broad approaches: direct adjustment, standardisation and inverse-probability-of-treatment weighting. Results: The three approaches are similar in being asymptotically efficient, in losing efficiency with mis-specified covariate functions and in handling designed balance. If a marginal estimand is targeted (for example, a risk difference or survival difference), then direct adjustment should be avoided because it involves fitting non-standard models that are subject to convergence issues. Convergence is most likely with IPTW. Robust standard errors used by IPTW are anti-conservative at small sample sizes. All approaches can use similar methods to handle missing covariate data. With missing outcome data, each method has its own way to estimate a treatment effect in the all-randomised population. We illustrate some issues in a reanalysis of GetTested , a randomised trial designed to assess the effectiveness of an electonic sexually transmitted infection testing and results service. Conclusions: No single approach is always best: the choice will depend on the trial context. We encourage trialists to consider all three methods more routinely.
The claims and statistics of this paper haven’t been checked yet.
Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.
Integrity signals
Registry
Cites
Statistics
Claims the paper makes
The claims and statistics of this paper haven’t been checked yet.
Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.
Claims other papers make about this one
Each is checked against this paper’s own text: does it say what the citing paper says it does?
Adjusting for baseline covariates, including those used in stratified randomisation, can lead to improved power to detect an intervention effect, particularly when a baseline covariate is prognostic of the outcome.
“Adjusting for baseline covariates, including those used in any stratified randomisation, is often advised in the analysis, particularly when a baseline covariate is prognostic of the outcome, as it can lead to improved power to detect an intervention effect.408 409 410”
From SPIRIT 2025 explanation and elaboration: updated guideline for protocols of randomised trials (2025) · cites this paper as [409]
Self-check
Percentages, sums and reported differences re-computed from the paper’s own numbers.
The self-check needs the paper’s full text.
Cites
Regression Models and Life-Tables
Cox, D. R. (1972) · Journal of the Royal Statistical Society Series B: Statistical Methodology · doi:10.1111/j.2517-6161.1972.tb00899.x · Cited by 39,793 · see citing works
Regression Models and Life-Tables
Cox, D. R. (1992) · Springer Series in Statistics · doi:10.1007/978-1-4612-4380-9_37 · Cited by 26,297 · see citing works
(2005) · Springer eBooks · doi:10.1007/0-387-27255-0_9 · Cited by 20,333 · see citing works
McCullagh, P., & Nelder, J. A. (1989) · doi:10.1007/978-1-4899-3242-6 · Cited by 16,836 · see citing works
A solution to the problem of separation in logistic regression
Heinze, G., & Schemper, M. (2002) · Statistics in Medicine · doi:10.1002/sim.1047 · Cited by 2,711 · see citing works
Oehlert, G. W. (1992) · The American Statistician · doi:10.1080/00031305.1992.10475842 · Cited by 1,308 · see citing works
The Arrangement of Field Experiments
Fisher, R. A. (1992) · Springer series in statistics · doi:10.1007/978-1-4612-4380-9_8 · Cited by 979 · see citing works
External validation of a Cox prognostic model: principles and methods
Royston, P. J., & Altman, D. G. (2013) · BMC Medical Research Methodology · doi:10.1186/1471-2288-13-33 · Cited by 911 · see citing works
Multiple-Imputation Inferences with Uncongenial Sources of Input
Meng, X. (1994) · Statistical Science · doi:10.1214/ss/1177010269 · Cited by 761 · see citing works
Desai, R. J., & Franklin, J. M. (2019) · BMJ · doi:10.1136/bmj.l5657 · Cited by 657 · see citing works
Guidelines for the Content of Statistical Analysis Plans in Clinical Trials
Gamble, C., Krishan, A., Stocken, D., Lewis, S., Juszczak, E., Doré, C., Williamson, P. R., Altman, D. G., Montgomery, A., Lim, P., et al. (2017) · JAMA · doi:10.1001/jama.2017.18556 · Cited by 536 · see citing works
Generalizing evidence from randomized clinical trials to target populations: The ACTG 320 trial.
Cole, S., & Stuart, E. (2010) · American Journal of Epidemiology · doi:10.1093/aje/kwq084 · Cited by 535 · see citing works
Snowden, J. M., Rose, S., & Mortimer, K. M. (2011) · American Journal of Epidemiology · doi:10.1093/aje/kwq472 · Cited by 514 · see citing works
The Relative Merits of Risk Ratios and Odds Ratios
Cummings, P. (2009) · Archives of Pediatrics and Adolescent Medicine · doi:10.1001/archpediatrics.2009.31 · Cited by 507 · see citing works
Kahan, B. C., Jairath, V., Doré, C. J., & Morris, T. P. (2014) · Trials · doi:10.1186/1745-6215-15-139 · Cited by 497 · see citing works
Self-citationAdjusting for partially missing baseline measurements in randomized trials
White, I. R., & Thompson, S. G. (2005) · Statistics in Medicine · doi:10.1002/sim.1981 · Cited by 378 · see citing works
Self-citationTsiatis, A. A., Davidian, M., Zhang, M., & Lu, X. (2007) · Statistics in Medicine · doi:10.1002/sim.3113 · Cited by 350 · see citing works
Improper analysis of trials randomised using stratified blocks or minimisation
Kahan, B. C., & Morris, T. P. (2011) · Statistics in Medicine · doi:10.1002/sim.4431 · Cited by 333 · see citing works
Self-citationShould multiple imputation be the method of choice for handling missing data in randomized trials?
Sullivan, T., White, I. R., Salter, A. B., Ryan, P., & Lee, K. J. (2016) · Statistical Methods in Medical Research · doi:10.1177/0962280216683570 · Cited by 307 · see citing works
Self-citationKahan, B. C., & Morris, T. P. (2012) · BMJ · doi:10.1136/bmj.e5840 · Cited by 294 · see citing works
Self-citationSeven myths of randomisation in clinical trials
Senn, S. J. (2012) · Statistics in Medicine · doi:10.1002/sim.5713 · Cited by 277 · see citing works
Avoiding bias due to perfect prediction in multiple imputation of incomplete categorical variables
White, I., Daniel, R., & Royston, P. (2010) · Computational Statistics & Data Analysis · doi:10.1016/j.csda.2010.04.005 · Cited by 223 · see citing works
Self-citationConditional and Marginal Models: Another View
Lee, Y., & Nelder, J. A. (2004) · Statistical Science · doi:10.1214/088342304000000305 · Cited by 213 · see citing works
Extending inferences from a randomized trial to a new target population
Dahabreh, I. J., Robertson, S. E., Steingrimsson, J. A., Stuart, E. A., & Hernán, M. Á. (2020) · Statistics in Medicine · doi:10.1002/sim.8426 · Cited by 207 · see citing works
Cro, S., Morris, T. P., Kenward, M. G., & Carpenter, J. R. (2020) · Statistics in Medicine · doi:10.1002/sim.8569 · Cited by 203 · see citing works
Self-citationMoore, K. L., & van der Laan, M. J. (2008) · Statistics in Medicine · doi:10.1002/sim.3445 · Cited by 185 · see citing works
Variance reduction in randomised trials by inverse probability weighting using the propensity score
Williamson, E., Forbes, A. B., & White, I. R. (2013) · Statistics in Medicine · doi:10.1002/sim.5991 · Cited by 173 · see citing works
Self-citationDaniel, R., Zhang, J., & Farewell, D. (2021) · Biometrical Journal · doi:10.1002/bimj.201900297 · Cited by 167 · see citing works
Wilson, E., Free, C., Morris, T. P., Syred, J., Ahamed, I., Menon-Johansson, A. S., Palmer, M. J., Barnard, S., Rezel‐Potts, E., & Baraitser, P. (2017) · PLoS Medicine · doi:10.1371/journal.pmed.1002479 · Cited by 127 · see citing works
Self-citation(2004) · Statistics in Medicine · doi:10.1002/sim.1647 · Cited by 122 · see citing works
Regression standardization with the R package stdReg
Sjölander, A. (2016) · European Journal of Epidemiology · doi:10.1007/s10654-016-0157-3 · Cited by 111 · see citing works
Leveraging prognostic baseline variables to gain precision in randomized trials
Colantuoni, E., & Rosenblum, M. (2015) · Statistics in Medicine · doi:10.1002/sim.6507 · Cited by 89 · see citing works
Raad, H., Cornelius, V. R., Chan, S., Williamson, E., & Cro, S. (2020) · BMC Medical Research Methodology · doi:10.1186/s12874-020-00947-7 · Cited by 77 · see citing works
Self-citationChoosing sensitivity analyses for randomised trials: principles
Morris, T. P., Kahan, B. C., & White, I. R. (2014) · BMC Medical Research Methodology · doi:10.1186/1471-2288-14-11 · Cited by 75 · cited 2× · see citing works
“This prompts sensitivity analysis [29].”
MethodSelf-citationHernández, A. V., Eijkemans, M. J. C., & Steyerberg, E. W. (2006) · Annals of Epidemiology · doi:10.1016/j.annepidem.2005.09.007 · Cited by 65 · see citing works
Propensity score weighting for covariate adjustment in randomized clinical trials
Zeng, S., Li, F., Wang, R., & Li, F. (2020) · Statistics in Medicine · doi:10.1002/sim.8805 · Cited by 60 · see citing works
Ideal vs. real: a systematic review on handling covariates in randomized controlled trials
Ciolino, J. D., Palac, H., Yang, A., Vaca, M., & Belli, H. M. (2019) · BMC Medical Research Methodology · doi:10.1186/s12874-019-0787-8 · Cited by 55 · see citing works
Turner, E. L., Perel, P., Clayton, T. C., Edwards, P. J., Hernández, A. V., Roberts, I., Shakur‐Still, H., & Steyerberg, E. W. (2011) · Journal of Clinical Epidemiology · doi:10.1016/j.jclinepi.2011.08.012 · Cited by 53 · see citing works
On the collapsibility of measures of effect in the counterfactual causal framework
Huitfeldt, A., Stensrud, M. J., & Suzuki, E. (2019) · NORA - Norwegian Open Research Archives · Cited by 51 · see citing works
Adaptive pre‐specification in randomized trials with and without pair‐matching
Balzer, L. B., van der Laan, M. J., & Petersen, M. L. (2016) · Statistics in Medicine · doi:10.1002/sim.7023 · Cited by 50 · see citing works
On the collapsibility of measures of effect in the counterfactual causal framework
Huitfeldt, A., Stensrud, M. J., & Suzuki, E. (2019) · Emerging Themes in Epidemiology · doi:10.1186/s12982-018-0083-9 · Cited by 47 · see citing works
On the logic of collapsibility for causal effect measures
Didelez, V., & Stensrud, M. J. (2021) · Biometrical Journal · doi:10.1002/bimj.202000305 · Cited by 43 · see citing works
Yelland, L. N., Salter, A. B., & Ryan, P. (2011) · The International Journal of Biostatistics · doi:10.2202/1557-4679.1278 · Cited by 34 · see citing works
Do Covariates Change the Estimand?
Permutt, T. (2019) · Statistics in Biopharmaceutical Research · doi:10.1080/19466315.2019.1647874 · Cited by 21 · see citing works
Wilson, E., Free, C., Morris, T. P., Kenward, M. G., Syred, J., & Baraitser, P. (2016) · JMIR Research Protocols · doi:10.2196/resprot.4094 · Cited by 13 · see citing works
Self-citationWilson, E., Free, C., Morris, T. P., Syred, J., & Baraitser, P. (2016) · JMIR Research Protocols · doi:10.2196/resprot.6280 · Cited by 8 · see citing works
Self-citationAnalysis of multicenter clinical trials with very low event rates
Kim, J., Troxel, A. B., Halpern, S. D., Volpp, K. G. M., Kahan, B. C., Morris, T. P., & Harhay, M. O. (2020) · Trials · doi:10.1186/s13063-020-04801-5 · Cited by 8 · see citing works
Self-citation
Flagged first, then by citations
Cited by
Sorted by citations
SPIRIT 2025 explanation and elaboration: updated guideline for protocols of randomised trials
Hróbjartsson, A., Boutron, I., Hopewell, S., Moher, D., Schulz, K. F., Collins, G. S., Tunn, R., Aggarwal, R., Berkwits, M., Berlin, J. A., et al. (2025) · BMJ · doi:10.1136/bmj-2024-081660 · Cited by 171 · see citing works
Self-citationAdjustment for Baseline Characteristics in Randomized Clinical Trials
Holmberg, M. J., & Andersen, L. W. (2022) · JAMA · doi:10.1001/jama.2022.21506 · Cited by 161 · see citing works
Key considerations for designing, conducting and analysing a cluster randomized trial
Hemming, K., & Taljaard, M. (2023) · International Journal of Epidemiology · doi:10.1093/ije/dyad064 · Cited by 90 · see citing works
Buntrock, C., Harrer, M., Sprenger, A. A., Illing, S., Sakata, M., Furukawa, T. A., Ebert, D. D., Cuijpers, P. J., Adriaanse, M. C., Albert, S. M., et al. (2024) · The Lancet Psychiatry · doi:10.1016/s2215-0366(24)00316-x · Cited by 63 · see citing works
Smit, J. M., van der Zee, P. A., Stoof, S. C. M., van Genderen, M. E., Snijders, D., Boersma, W. G., Confalonieri, P., Salton, F., Confalonieri, M., Shih, M., et al. (2025) · The Lancet Respiratory Medicine · doi:10.1016/s2213-2600(24)00405-3 · Cited by 64 · see citing works
Levofloxacin Preventive Treatment in Children Exposed to MDR Tuberculosis
Hesseling, A. C., Purchase, S. E., Martinson, N. A., Fairlie, L., Schaaf, H. S., Brigden, J., Staples, S., Gibb, D. M., Garcia‐Prats, A. J., Conradie, F., et al. (2024) · New England Journal of Medicine · doi:10.1056/nejmoa2314318 · Cited by 62 · see citing works
Measuring the performance of prediction models to personalize treatment choice
Efthimiou, O., Hoogland, J., Debray, T. P. A., Seo, M., Furukawa, T. A., Egger, M., & White, I. R. (2023) · Statistics in Medicine · doi:10.1002/sim.9665 · Cited by 47 · see citing works
Self-citationCovariate adjustment in randomized controlled trials: General concepts and practical considerations
Lancker, K. V., Bretz, F., & Dukes, O. (2024) · Clinical Trials · doi:10.1177/17407745241251568 · Cited by 44 · see citing works
A Meta-Analysis of Levofloxacin for Contacts of Multidrug-Resistant Tuberculosis
Duong, T., Brigden, J., Schaaf, H. S., Garden, F. L., Marais, B. J., Nguyen, T. A., White, I. R., Gibb, D. M., Nhung, N. V., Martinson, N. A., et al. (2024) · NEJM Evidence · doi:10.1056/evidoa2400190 · Cited by 41 · see citing works
Self-citationPulsed field vs radiofrequency ablation for paroxysmal atrial fibrillation: the BEAT PAROX-AF trial
Jaı̈s, P., Neužil, P., Scherr, D., Frison, É., Knecht, S., Bovéda, S., Deisenhofer, I., Maury, P., Deneke, T., Cochet, H., et al. (2026) · European Heart Journal · doi:10.1093/eurheartj/ehaf1115 · Cited by 39 · see citing works
Tackney, M. S., Morris, T. P., White, I. R., Leyrat, C., Diaz‐Ordaz, K., & Williamson, E. (2023) · Trials · doi:10.1186/s13063-022-06967-6 · Cited by 34 · see citing works
Self-citationThe Causal Cookbook: Recipes for Propensity Scores, G-Computation, and Doubly Robust Standardization
Chatton, A., & Rohrer, J. M. (2024) · Advances in Methods and Practices in Psychological Science · doi:10.1177/25152459241236149 · Cited by 33 · see citing works
Missing data: Issues, concepts, methods
Pham, T. M., Pandis, N., & White, I. R. (2024) · Seminars in Orthodontics · doi:10.1053/j.sodo.2024.01.007 · Cited by 25 · see citing works
Self-citationPractical considerations for sample size calculation for cluster randomized trials
Leyrat, C., Eldridge, S. M., Taljaard, M., & Hemming, K. (2024) · Journal of Epidemiology and Population Health · doi:10.1016/j.jeph.2024.202198 · Cited by 20 · see citing works
Magee, L. A., Kirkham, K., Tohill, S., Gkini, E., Moakes, C. A., Dorling, J. S., Green, M., Hutcheon, J. A., Javed, M., Kigozi, J., et al. (2024) · PLoS Medicine · doi:10.1371/journal.pmed.1004481 · Cited by 21 · see citing works
Shi, A. X., Zivich, P., & Chu, H. (2024) · Applied Sciences · doi:10.3390/app14093662 · Cited by 13 · see citing works
Categorisation of continuous covariates for stratified randomisation: How should we adjust?
Sullivan, T., Morris, T. P., Kahan, B. C., Cuthbert, A. R., & Yelland, L. N. (2024) · Statistics in Medicine · doi:10.1002/sim.10060 · Cited by 15 · see citing works
Self-citationLombardo, F. L., Alegiani, S. S., Mayer, F., Cipriani, M., Giudice, M. L., Ludolph, A. C., McDermott, C. J., Corcia, P., Damme, P. V., van den Berg, L. H., et al. (2023) · Trials · doi:10.1186/s13063-023-07638-w · Cited by 13 · see citing works
Cooke, G., Hung, L. M., Flower, B., McCabe, L., Hang, V. T. K., Thu, V. T. K., Trọng, T. Đ., Dung, N. T., Phuong, L. T., Khoa, D. B., et al. (2025) · The Lancet · doi:10.1016/s0140-6736(25)00097-2 · Cited by 13 · see citing works
Self-citationTurkova, A., Chan, M. K., Kityo, C. M., Kekitiinwa, A., Musoke, P., Violari, A., Variava, E., Archary, M., Cressey, T. R., Chalermpantmetagul, S., et al. (2024) · Contemporary Clinical Trials · doi:10.1016/j.cct.2024.107540 · Cited by 9 · see citing works
Self-citationTransportability of model‐based estimands in evidence synthesis
Remiro‐Azócar, A. (2024) · Statistics in Medicine · doi:10.1002/sim.10111 · Cited by 9 · see citing works
Saint-Genis, Q., Birckener, J., Gourdou, V., Nicolle, C., Garnier, M., Schwindenhammer, V., Hannezo, C., Aveline, C., Cinotti, R., Puisney, B., et al. (2025) · BMJ Open · doi:10.1136/bmjopen-2024-088306 · Cited by 8 · see citing works
Wei, J., Xu, J., Bornkamp, B., Lin, R., Tian, H. S., Xi, D., Zhang, X., Zhao, Z., & Roychoudhury, S. (2023) · Statistics in Biopharmaceutical Research · doi:10.1080/19466315.2023.2292774 · Cited by 8 · see citing works
van der Veer, S. N., Griffiths-Jones, D., Parkes, M. J., Druce, K. L., Amlani-Hatcher, P., Armitage, C. J., Bansback, N. J., Bower, P., Dowding, D., Ellis, B. M., et al. (2024) · Trials · doi:10.1186/s13063-024-08497-9 · Cited by 8 · see citing works
Sherry, A. D., Passy, A. H., McCaw, Z. R., Jaoude, J. A., Lin, T. A., Kouzy, R., Miller, A. M., Kupferman, G. S., Beck, E. J., Msaouel, P., et al. (2024) · JCO Clinical Cancer Informatics · doi:10.1200/cci.24.00102 · Cited by 7 · see citing works
Pham, T. M., Kahan, B. C., Lopes, A., Rashid, M., Hoskin, P., & White, I. R. (2025) · Clinical Trials · doi:10.1177/17407745251360645 · Cited by 7 · see citing works
Self-citationJanani, L., Phillips, R., Vogt, E. V., Liu, X., Waddington, C. S., & Cro, S. (2024) · Clinical & Experimental Immunology · doi:10.1093/cei/uxae104 · Cited by 8 · see citing works
Covariate adjustment in cluster randomised trials: a practical guide
Hemming, K., Hall, J. J., Copas, A. J., Watson, S., Taljaard, M., & Hooper, R. (2025) · BMJ · doi:10.1136/bmj-2025-084194 · Cited by 6 · see citing works
Sahai, N., Arunachalam, D. K., Morris, T. P., Copas, A. J., Samuel, P., Mohan, V. R., Abraham, V. J., Selwyn, J. A., Kumar, P., Rose, W., et al. (2023) · Trials · doi:10.1186/s13063-023-07555-y · Cited by 6 · see citing works
Self-citationPapastefanou, I., Chen, Y.-Y., Nguyen‐Hoang, L., Nguyen, D., Dinh, L. T., Pooh, R. K., Shiozaki, A., Zheng, M., Hu, Y., Wu, Y.-P., et al. (2025) · BJOG An International Journal of Obstetrics & Gynaecology · doi:10.1111/1471-0528.18211 · Cited by 6 · see citing works
Medcalf, E., Taylor, A., Turner, R. M., Espinoza, D., & Bell, K. (2022) · Contemporary Clinical Trials · doi:10.1016/j.cct.2022.106761 · Cited by 6 · see citing works
Less is More? First Impressions From COSMIC-313
Msaouel, P. (2022) · Cancer Investigation · doi:10.1080/07357907.2022.2136681 · Cited by 6 · see citing works
Two-stage matching-adjusted indirect comparison
Remiro‐Azócar, A. (2022) · BMC Medical Research Methodology · doi:10.1186/s12874-022-01692-9 · Cited by 20 · see citing works
Martínez, C. D. G., & Corredor, J. (2024) · Memory & Cognition · doi:10.3758/s13421-024-01616-6 · Cited by 5 · see citing works
Model-based standardization using multiple imputation
Remiro‐Azócar, A., Heath, A., & Baio, G. (2024) · BMC Medical Research Methodology · doi:10.1186/s12874-024-02157-x · Cited by 5 · see citing works
Hemming, K., Thompson, J., Taljaard, M., Watson, S. I., Kasza, J., Thompson, J. A., Kahan, B. C., & Copas, A. J. (2024) · Trials · doi:10.1186/s13063-024-08653-1 · Cited by 5 · see citing works
Thompson, J., Watson, S., Middleton, L., & Hemming, K. (2025) · Trials · doi:10.1186/s13063-024-08690-w · Cited by 5 · see citing works
The variance of causal effect estimators for binary v-structures
Kuipers, J., & Moffa, G. (2022) · Journal of Causal Inference · doi:10.1515/jci-2021-0025 · Cited by 5 · see citing works
Bridged treatment comparisons: an illustrative application in HIV treatment
Zivich, P. N., Cole, S. R., Edwards, J. K., Shook‐Sa, B. E., Breskin, A., & Hudgens, M. G. (2024) · American Journal of Epidemiology · doi:10.1093/aje/kwae340 · Cited by 5 · see citing works
Kahan, B. C., Bretz, F., Copas, A. J., Harhay, M. O., Collins, P. G. S., Bahti, M., Bi, D., Campbell, M., Courtright, K. R., Feeney, T., et al. (2026) · BMJ · doi:10.1136/bmj-2025-089050 · Cited by 4 · see citing works
Abdulmajeed, J., Khatib, M., Dulli, M. W., Sioufi, S., Al-Khulaifi, A., Stone, J., Furuya‐Kanamori, L., Onitilo, A. A., & Doi, S. A. R. (2023) · Cancer Epidemiology · doi:10.1016/j.canep.2023.102521 · Cited by 4 · see citing works
Design and analysis of randomized clinical trials of embryo diagnostics: phase 3
Wilkinson, J., Goodman, L. R., Hill, M. J., Seli, E. U., & Forman, E. J. (2025) · Fertility and Sterility · doi:10.1016/j.fertnstert.2025.07.017 · Cited by 4 · see citing works
Wei, J., Mozumder, S. I., Li, L., Xi, D., Xu, J., Lin, R., Sverdlov, O., Chipman, J., & Conditional, M. T. F. U. A. O. E. W. G. (2025) · BMC Medical Research Methodology · doi:10.1186/s12874-025-02670-7 · Cited by 4 · see citing works
Garioud, A. L. D. B., Andersen, L. P. K., Jensen, A. K. G., Do, H. Q., Jakobsen, J. C., Holst, L. B., Rasmussen, L. S., & Afshari, A. (2023) · Acta Anaesthesiologica Scandinavica · doi:10.1111/aas.14342 · Cited by 4 · see citing works
Fell, M. J., Phippen, G., van Eeden, S., Chong, D. K., Swan, M. C., Eeden, S. V., & Carlin, J. B. (2024) · The Cleft Palate-Craniofacial Journal · doi:10.1177/10556656241253949 · Cited by 4 · see citing works
Nurmi, V., Mayne, R., Knight, C., Almonacid-Mendoza, H. L., Secret, S., Estcourt, L. J., Hepojoki, J., Šuštić, T., Lamikanra, A., Tsang, H. P., et al. (2025) · Journal of Infection · doi:10.1016/j.jinf.2025.106412 · Cited by 4 · see citing works
Katongole, F., Arumugam, T., Jennings, A. C., Mutata, C., Ssebunya, P., Wamboi, C., Green, A., Bwakura‐Dangarembizi, M., Kityo, C. M., Siika, A. M., et al. (2025) · Contemporary Clinical Trials · doi:10.1016/j.cct.2025.107963 · Cited by 4 · see citing works
Perneger, T., Combescure, C., & Poncet, A. (2023) · Trials · doi:10.1186/s13063-022-07053-7 · Cited by 4 · see citing works
White, I. R., Morris, T. P., & Williamson, E. (2021) · arXiv (Cornell University) · doi:10.48550/arxiv.2107.07278 · Cited by 6 · see citing works
Self-citationJennings, A. C., Rutherford, M. J., Latimer, N. R., Sweeting, M. J., & Lambert, P. C. (2023) · Value in Health · doi:10.1016/j.jval.2023.12.008 · Cited by 3 · see citing works
Covariate adjustment and estimation of difference in proportions in randomized clinical trials
Liu, J., & Xi, D. (2024) · Pharmaceutical Statistics · doi:10.1002/pst.2397 · Cited by 3 · see citing works
Chen, Y., Nguyen‐Hoang, L., Dinh, L. T., Nguyen, D.-A., Pooh, R. K., Shiozaki, A., Zheng, M., Hu, Y., Ma, R., Kusuma, A., et al. (2025) · The Lancet Regional Health - Western Pacific · doi:10.1016/j.lanwpc.2025.101582 · Cited by 3 · see citing works
Lombardo, F. L., Alegiani, S. S., Mayer, F., Cipriani, M., Giudice, M. L., Ludolph, A. C., McDermott, C. J., Corcia, P., Damme, P. V., van den Berg, L. H., et al. (2023) · Research Square · doi:10.21203/rs.3.rs-3182336/v1 · Cited by 3 · see citing works
Aslanyan, V., Pickering, T. A., Nuño, M. M., Renfro, L. A., Pa, J., & Mack, W. J. (2024) · Pharmaceutical Statistics · doi:10.1002/pst.2443 · Cited by 2 · see citing works
Covariate adjustment in randomized trials: An overview
Pocock, S. (2026) · Clinical Trials · doi:10.1177/17407745261434564 · Cited by 2 · see citing works
Zivich, P. N., & Shook‐Sa, B. E. (2024) · American Journal of Epidemiology · doi:10.1093/aje/kwae316 · Cited by 2 · see citing works
Erdmann, S., Edelmann, D., & Kieser, M. (2023) · Biometrical Journal · doi:10.1002/bimj.202200023 · Cited by 1 · see citing works
Statistical Design and Reporting of Randomised Controlled Trials for Raynaud’s Phenomenon
Wilkinson, J., & Seibold, J. R. (2024) · Springer eBooks · doi:10.1007/978-3-031-52581-0_16 · Cited by 1 · see citing works
Covariate Adjustment in Analyzing Randomized Clinical Trials: Approaches, Software, and Application
Liu, J., Wang, X., & Pang, H. (2024) · Springer eBooks · doi:10.1007/978-3-031-65937-9_14 · Cited by 1 · see citing works
Jennings, A. C., Rutherford, M. J., & Lambert, P. C. (2025) · Statistics in Medicine · doi:10.1002/sim.70035 · Cited by 1 · see citing works
Weinfurt, K. P. (2025) · Quality of Life Research · doi:10.1007/s11136-025-03952-9 · Cited by 1 · see citing works
Tackling control risk problems in non-inferiority trials
White, I. R., Quartagno, M., Babiker, A. G., Turner, R., Parmar, M., & Walker, A. S. (2025) · BMJ Medicine · doi:10.1136/bmjmed-2023-000845 · Cited by 1 · see citing works
Self-citationOoghe, A., Pereira, Á. R., Jr., Colloca, L., Stannard, E., Ambrose, C., Lissin, D., & Branders, S. (2025) · Journal of Pain · doi:10.1016/j.jpain.2025.105489 · Cited by 1 · see citing works
Adams, L. A., de Guingand, D. L., Jeffrey, G. P., Thompson, A. J. V., Strasser, S. I., Crawford, D. H., Collins, L. G., Reid, C. M., Wallace, M., Chondros, P., et al. (2025) · Trials · doi:10.1186/s13063-025-09037-9 · Cited by 1 · see citing works
Experimental Design and Causal Inference
Almusaed, A., Almssad, A., & Yitmen, İ. (2025) · Springer eBooks · doi:10.1007/978-3-031-97393-2_16 · Cited by 1 · see citing works
Beyond observational data: understanding anaesthesia research better with causal diagrams
Wyffels, P., Decruyenaere, A., & Wouters, P. (2026) · European Journal of Anaesthesiology · doi:10.1097/eja.0000000000002355 · Cited by 1 · see citing works
Smith, G. C. S., Sutton-Cole, A., Dyer, E., Sovio, U., Cook, E., White, I. R., & Jones, D. S. (2026) · BMJ Open · doi:10.1136/bmjopen-2026-122043 · Cited by 1 · see citing works
Self-citationBullen, J., Nickel, B., McCaffery, K. J., Wilt, T. J., Smith, J., Boroumand, F., Parker, L. M., Millar, J. L., Brodersen, J., Dahm, P., et al. (2024) · BMJ Open · doi:10.1136/bmjopen-2024-085947 · Cited by 1 · see citing works
Basu, J., Parsons, N., Friede, T., & Stallard, N. (2024) · Statistical Methods in Medical Research · doi:10.1177/09622802241288350 · Cited by 1 · see citing works
Smith, G. C. S., Sutton-Cole, A., Dyer, E., Sovio, U., Cook, E., White, I. R., & Jones, D. S. (2026) · medRxiv · doi:10.64898/2026.04.29.26352041 · Cited by 1 · see citing works
Self-citationCarpenter, J. R., Kenward, M. G., Bartlett, J. W., Morris, T. P., Quartagno, M., & Wood, A. (2023) · Wiley eBooks · doi:10.1002/9781119756118.ref
Self-citationFranklin, M. K., Porter, A., de Vocht, F., Kearns, B., Latimer, N. R., Alava, M. H., Young, T. A., & Kidger, J. (2023) · Research Square · doi:10.21203/rs.3.rs-3317541/v1
Katongole, F., Arumugam, T., Jennings, A. C., Mutata, C., Ssebunya, P., Wamboi, C., Green, A., Bwakura‐Dangarembizi, M., Kityo, C. M., Siika, A. M., et al. (2025) · SSRN Electronic Journal · doi:10.2139/ssrn.5152849
Causal Estimands for Policy Evaluation and BeyondPreprint
Соколов, Б. О. (2025) · doi:10.31235/osf.io/4vtpk_v1
Baayen, C., Blanche, P., Jennison, C., & Ozenne, B. (2025) · Statistics in Medicine · doi:10.1002/sim.70130
Causal Estimands for Policy Evaluation and BeyondPreprint
Соколов, Б. О. (2025) · doi:10.31235/osf.io/4vtpk_v2
Tarzia, L., Chondros, P., Trevena, J. A., Hegarty, K. L., Russell, M. A., & Sanci, L. A. (2025) · Journal of Sexual Aggression · doi:10.1080/13552600.2025.2550296
Meier, K., Risør, B. W., Poulsen, D. M., Sørensen, J. C. H., & Dehbarez, N. T. (2025) · European Journal of Pain · doi:10.1002/ejp.70160
How to manage missing covariates in randomized controlled trials: a comparison of strategies
Zhang, S., Si, Y., & Dziak, J. J. (2025) · BMC Medical Research Methodology · doi:10.1186/s12874-025-02708-w
Causal estimands for social scientific research
Соколов, Б. О. (2025) · Sociology methodology methods mathematical modeling (Sociology 4M) · doi:10.19181/4m.2025.34.2.1
Tackney, M. S., Morris, T., White, I. R., Leyrat, C., Diaz‐Ordaz, K., & Williamson, E. (2024) · Figshare · doi:10.6084/m9.figshare.26559575
Self-citationLombardo, F. L., Alegiani, S. S., Mayer, F., Cipriani, M., Giudice, M. L., Ludolph, A. C., McDermott, C. J., Corcia, P., Damme, P. V., van den Berg, L. H., et al. (2024) · Figshare · doi:10.6084/m9.figshare.26649900
Perneger, T., Combescure, C., & Poncet, A. (2023) · Figshare · doi:10.6084/m9.figshare.22608883
Tackney, M. S., Morris, T., White, I. R., Leyrat, C., Diaz‐Ordaz, K., & Williamson, E. (2024) · Figshare · doi:10.6084/m9.figshare.26559578
Self-citationSahai, N., Arunachalam, D. K., Morris, T., Copas, A. J., Samuel, P., Mohan, V. R., Abraham, V., Selwyn, J. A., Kumar, P., Rose, W., et al. (2023) · Figshare · doi:10.6084/m9.figshare.23849514
Self-citationSahai, N., Arunachalam, D. K., Morris, T., Copas, A. J., Samuel, P., Mohan, V. R., Abraham, V., Selwyn, J. A., Kumar, P., Rose, W., et al. (2023) · Figshare · doi:10.6084/m9.figshare.23849517
Self-citationTackney, M. S., Morris, T., White, I. R., Leyrat, C., Diaz‐Ordaz, K., & Williamson, E. (2024) · Figshare · doi:10.6084/m9.figshare.26559569
Self-citationTackney, M. S., Morris, T., White, I. R., Leyrat, C., Diaz‐Ordaz, K., & Williamson, E. (2024) · Figshare · doi:10.6084/m9.figshare.26559572
Self-citationStatistical Analysis Under the Estimand Framework: Covariate Adjustment
Lancker, K. V., Bannick, M. S., & Ye, T. (2025) · Springer series in pharmaceutical statistics · doi:10.1007/978-3-032-02192-2_20
Patient-Led Insulin Titration for Glycemic Management With Gestational Diabetes Mellitus
Wang, X.-Y., Grobman, W. A., Wu, J., Suzawa, R., Kralik, J., Summerfield, T. L. S., Vickers, S., Widmayer, B., Rainier, M., Somppi, J., et al. (2026) · Obstetrics and Gynecology · doi:10.1097/aog.0000000000006154
Kekitiinwa, A., Jennings, A. C., Bwakura‐Dangarembizi, M., Kityo, C. M., Siika, A. M., Archary, M., Green, A., Jafta, L., Akabwai, G. P., Mujuru, H. A., et al. (2026) · The Lancet HIV · doi:10.1016/s2352-3018(25)00326-1
Alleyrat, C., Drilleau, R., Brasseur, J.-M., Karayan, J., Saenz-Molina, C., Frasca, D., Boisson, M., & Beaumatin, G. (2026) · BMJ Open · doi:10.1136/bmjopen-2025-112540
Shao, Y., Lyu, L., Yu, M., & Wang, B. (2026) · Journal of Clinical Epidemiology · doi:10.1016/j.jclinepi.2026.112374
Jun, H., Lee, K.-H., Tapia, D. U., Calzo, J. P., & Corliss, H. L. (2026) · Sensors · doi:10.3390/s26123872
Should We Adjust for Baseline Covariates in Randomized Clinical Trials?
Gueorguieva, R. V. (2026) · The Journal of Nervous and Mental Disease · doi:10.1097/nmd.0000000000001876
Fitzpatrick, S., Arunagiri, V., Traynor, J. M., Fredborg, B. K., Daros, A. R., Crenshaw, A. O., Fitzpatrick, D., McMain, S., Monson, C. M., Courey, L., et al. (2026) · BMC Psychiatry · doi:10.1186/s12888-026-08374-6
Barnett, P. G., Gilstad‐Hayden, K., Lazar, C. M., Martino, S., & Rosen, M. I. (2026) · BMJ Open · doi:10.1136/bmjopen-2026-119224
Stevens, S., Barnish, M. S., Lovell, A., Jones, F. G., Perks, J., Meléndez‐Torres, G. J., Nikram, E., Hatswell, A. J., Marques, E., Franklin, M., et al. (2026) · PharmacoEconomics · doi:10.1007/s40273-026-01644-x
Bwakura‐Dangarembizi, M., Chappell, E., Kityo, C. M., Anena, D. L., Kiilu, C., Archary, M., Jafta, L., Mujuru, H. A., Nakabuye, S., Akabwai, G. P., et al. (2026) · The Lancet · doi:10.1016/s0140-6736(26)01537-0
- Authors
- Morris, T. P., Walker, A. S., Williamson, E. J., & White, I. R.
- Affiliations
- London School of Hygiene & Tropical Medicine (GB)
- MRC Clinical Trials Unit at UCL (GB)
- Corresponding author
- Morris, Tim P.
- Venue
- Trials
- Published
- 2022-04-18
- Volume
- 23
- Issue
- 1
- Pages
- 328-328
- ISSN
- 1745-6215 (ISSN-L)
- PMC
- PMC9014627
- OpenAlex
- W3180549268
- Cited by
- 97
- References
- 47
- Citations by year
- 2026: 17 · 2025: 28 · 2024: 29 · 2023: 17 · 2022: 5 · 2021: 1
- FWCI
- 15.12
- Type
- journal article
- Language
- en
- Open access
- gold
- doi.org
- Locations
- Trials (publishedVersion, cc-by)
- PubMed Central (publishedVersion, cc-by)
- PubMed (publishedVersion)
- LSHTM Research Online (London School of Hygiene and Tropical Medicine) (acceptedVersion)
- DOAJ (DOAJ: Directory of Open Access Journals) (submittedVersion, cc-by-sa)
- UCL Discovery (University College London) (submittedVersion)
- Funders
- medical research council (MC_UU_12023/21, MC_UU_12023/29, MR/L004933/2/N96, MR/S01442X/1)
- Topics
- Physical Sciences › Mathematics › Statistics and Probability › Statistical Methods in Clinical Trials
- Physical Sciences › Mathematics › Statistics and Probability › Advanced Causal Inference Techniques
- Physical Sciences › Mathematics › Statistics and Probability › Statistical Methods and Bayesian Inference
- Keywords
- covariate adjustment, baseline covariates, statistical analysis plan, standardization, inverse probability of treatment weighting, robust standard errors, missing covariates, missing outcome data, treatment effect estimation
- MeSH terms
- Humans, Probability, Research Design, Sample Size
About these checks
Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.
Statistics and arithmetic are recomputed, not judged.
Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.
What counts as a claim ›How we measure confidence ›How we check this ›
Are you an author, or do you see a problem with this page? Request a review