To the Editor: I am perplexed and troubled by the implications of the provocative article by Waterbor and colleagues (May 12 issue).* The fundamental problem lies in drawing clinical inferences from a purely statistical argument, whose fundamental assumptions are fraught with controversy. Other problems with their report include the large number of obviously important but uncontrolled variables (e.g., 72 percent of baseball players reported another occupation) and the clearly unrepresentative numbers of subgroup members (e.g., the sum of pitchers and catchers in the study equaled the number of infielders and outfielders). Preexisting or unrelated medical conditions were not reviewed, and. © 1988, Massachusetts Medical Society. All rights reserved.