A RETROSPECTIVE COHORT STUDY ON THE INCIDENCE OF HAND DERMATITIS IN NURSES

Data on the incidence and induction time of hand dermatitis are not available from the literature. To assist the planning of a prospective study on risk factors for hand dermatitis, a retrospective cohort study was performed in nurses and office employees to obtain a rough estimate of the incidence and induction time of hand dermatitis in these occupational groups. Data were collected by means of a self-administered questionnaire with validated questions on symptoms of hand dermatitis. The cohort consisted of 371 nurses and 111 office employees who were newly employed by a University Hospital between 1 January 1987 and 31 December 1988. Follow-up ended on 30 September 1989. Subjects who reported that symptoms had already occurred before entering the study were excluded for analysis on the incidence, leaving 298 nurses and 101 office employees for further analysis. Due to limitations of the retrospective study design, only half of the cases were able to report the exact month of occurrence of symptoms. Therefore only a rough estimate could be made of the incidence and induction period, assuming that the distribution of person-months of observation in cases with a known incidence date was equal to that of cases with unknown incidence dates. Thus, it was estimated that the overal incidence was 6.5 cases/1000 person-months in nurses and 1 case/1000 person-months in office employees. In nurses, 72% of the cases occurred within 3 months of follow-up. However, in the interpretation of these figures it should be taken into account that 83% of the nurses had been working as a nurse before the start of employment by the University Hospital. Since these nurses may represent a less susceptible group with a lower incidence, it should be considered whether a prospectice study should focus on apprentice nurses who have not been occupationally exposed as nurses before entering that study.