I’ve recently had the opportunity to spend a little time looking at an interesting approach for improving the efficiency of estimated treatment effects in clinical trials which exploits historical data. In this blog post I’ll give a few thoughts on the results in ‘Increasing the efficiency of randomized trial estimates via linear adjustment for a prognostic score’, by Schuler et al 2022. The paper was published in the International Journal of Biostatistics, and an arXiv pre-print is available here.