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The prevalence and incidence of medical conditions in healthy pharmaceutical company employees who volunteer to participate in medical research.

AIMS
Although clinical research in healthy volunteers is commonly performed there have been few studies of the value of the medical screening of subjects. The aim of this study was to investigate the prevalence and incidence of medical conditions found during the medical screening of 'healthy' subjects employed in a pharmaceutical company who volunteered to participate in medical research.


METHODS
This was a retrospective study of the medical notes of all the subjects who volunteered for membership of the Zeneca Clinical Pharmacology Unit's healthy volunteer panel over a 4 year period from 1990 to 1994. The prevalence of medical conditions found at presentation was determined. The incidence of medical conditions during the 4 year observation period was also ascertained. Medical screening included a full medical history and examination, clinical chemistry, haematology and urinalysis screens, pulmonary function tests, ECGs, 24 h ambulatory cardiac monitoring and a request for information from the volunteer's General Practitioner.


RESULTS
Prevalence-1293 subjects volunteered to join the panel of which 156 subjects (12%) were not accepted at presentation including 141 (10. 9%) for medical reasons. The most medical common reasons were; previously diagnosed medical conditions (3.3%), cardiovascular abnormalities (1.9%), abnormal liver function tests (1.9%), anaemia (1.2%), hyperlipidaemia (1.1%), excess alcohol intake (0.6%) and thyroid disease (0.5%). Incidence-36 of the 1137 volunteers (0.8% per year) accepted onto the panel subsequently developed medical conditions of which the most common were; anaemia (0.29% per year), cardiovascular abnormalities (0.13% per year) and vasovagal syncope (0.13% per year).


CONCLUSIONS
This study demonstrates the importance of medical screening before healthy volunteers participate in clinical research.