[Accidents with biological materials among nurses in a training hospital: case-control study]

This case-control study aimed at analyzing the association between occupational stress and disagreement between chronotype and the work shift of nurses who suffered accidents with biological materials in a hospital of Porto Alegre, Rio Grande do Sul, Brazil. A number of 99 workers who suffered accidents (cases) and 232 that had not suffered accidents (controls) were interviewed. Data were collected through the Job Stress Scale according to Karasek's model and the Horne-Ostberg scale The occurrence of accident was not statistically associated with high work requirement scores (p = 0.317), with a chronobiological profile discordant with work shift (p = 0.563), or with other labor variables associated to accidents--overtime, having two jobs (p = 1.000). In addition, there was no significant difference (chi2 Pearson; p = 1.00) among the scores of professionals with high work requirements who work in shifts discordant with their chronotype, both in the case group and in the control group as well.