How much does this article add to prior research? Paul von Hippel, University of Texas 12 June 2015 I was interested in Rodwell et al.'s  article on the topic of imputing limited-range variables, and pleased to see that they reached approximately the same conclusion as my earlier article on imputing skewed variables . Like me, Rodwell et al. concluded that imputation imputing skewed variables as though they were normal can produce good though not entirely unbiased estimates for some quantities. Like me, Rodwell et al. concluded that methods that try to “correct” the imputations by rounding, transformation, or truncation often make biases worse instead of better. Unfortunately Rodwell et al.'s description of my prior research is incomplete and gives the impression that their results are more novel than they are. In introducing their article, Rodwell et al. cite “the limited comparison of methods for handling limited-range variables to date.” As an example of those limitations, they report that my prior article “was fairly restrictive as [it] only considered data from an exponential distribution with the lower range restricted." In the prepublication history I see that one of the reviewers suggested that my article was limited to the case where variables were missing completely at random (MCAR). In fact my article was not limited to exponential MCAR data. While I did begin with exponential MCAR data, I continued with a broad simulation that considered 4 different distributions (including but not limited to the exponential); 3 different patterns of missing values (including but not limited to the MCAR pattern); data with 1, 2, and 3 variables, and 5 different relationships between the incomplete variable and the complete variables; 7 different methods of imputation; and 8 different estimands. The simulation was a lot of work and offered a lot of evidence about the properties of different estimators under different circumstances. It troubles me that authors and reviewers working in this area apparently did not see the simulation when they reviewed my article. It might have helped them to identify gaps in knowledge and make a more novel contribution themselves. To their credit, Rodwell et al. did evaluate the method of predictive mean matching, a method that I did not cover. There is definitely room for further research in this area. Sincerely yours, Paul von Hippel University of Texas, Austin Rodwell L, Lee KJ, Romaniuk H, Carlin JB. Comparison of methods for imputing limited-range variables: a simulation study. BMC Medical Research Methodology. 2014;14(1):57. doi:10.1186/1471-2288-14-57. von Hippel PT. Should a Normal Imputation Model be Modified to Impute Skewed Variables? Sociological Methods & Research. 2013;42(1):105-138. doi:10.1177/0049124112464866. Competing interests I have no competing interests except that I wrote a previous article on the subject.