Characteristics of driving in relation to the drug and alcohol use of Finnish outpatients.

A questionnaire was administered to 765 rheumatoid arthritic, 715 tubercular and 1,050 psychiatric outpatients and to 587 control subjects concerning their use of drugs and alcohol, driving habits and traffic accident involvement. The driving populations of all groups were matched as to their age and area of residence. The results of the study show a relatively very small number of driving licence holders among rheumatoid and psychiatric patients whereas the tubercular group includes as many driving licences as the control group. Also, the annual driving experience of the rheumatoid arthritic and psychiatric patients was low. The main reason for driving was recreation, and the driving mainly took place on highways. Excluding the psychiatric patients, the patient groups had been involved less often in traffic accidents that the controls. The use of drugs correlated inversely with driving: the more you used drugs the less you drove. Also the consumption of alcohol increased in direct proportion to the number of kilometres driven: the greater the alcohol consumption per drinking session, the more you drove annually and were involved in accidents.