To the Editor:
We would like to congratulate C. John Michet 3rd, et al1 on their excellent paper highlighting the issues of relying on hospital data for epidemiological studies. Routinely collected medical data, such as those found in hospital case notes, are an increasingly important resource for research, and therefore understanding the strengths and weaknesses of these data is important to clinicians and …
Address correspondence to Professor C.D. Mallen, Research Institute for Primary Care and Health Sciences, Keele University, Keele, Staffordshire ST55 BG, UK. E-mail: c.d.mallen{at}keele.ac.uk