To the Editor.—
Dr Howell1 is to be commended for his systematic examination of patient records at the Pennsylvania Hospital to determine the application of new technology. Such an approach is obviously the "gold standard" in any assessment of how often such technologies (roentgenography and electrocardiography) were actually used in patient care. However, it is possible to infer usage from "how they [the technologies] were described in the published literature," especially when that literature emanates from the hospital being studied. When your attending physician wrote the book, you tend to order tests described in that book. Such a situation existed at The Johns Hopkins Hospital in the early 1900s. Comparisons between the two hospitals in their application of x-ray machines, electrocardiographs, and chart formats therefore seem possible and useful.The early utilization of x-ray machines at The Johns Hopkins Hospital was similar to that described at the Pennsylvania Hospital.