Fig. 2

Excess sickness absence rate and etiological fraction of psychosocial work characteristics

Panel a shows the calculation of the etiological fraction as suggested by Miettinen [19]. The vertical axis displays the ratio of sickness absence in each quartile of psychosocial work characteristics in comparison to the sickness absence in the most favorable quartile (high) as reference group. The shaded area represents the surplus attributable to less favorable psychosocial work characteristics as in the reference group. The etiological fraction is the proportion of the shaded surplus absence of the entire absence. The data is the average of 200 bootstrap cycles of weighted random sampling within each work-group. The calculation for the excess absence rate above expected baseline is as follows: (shaded area (sa)): sa = 0.29 * 0.42 + 0.17 * 0.63 + 0.28 * 0.90 = 0.48. The calculation for the etiological fraction (the amount of overall reduction if psychosocial work characteristics were like the “very good” quartile of work-groups) is: sa / (1 sa): EF = 0.48 / 1.48 = 0.32. Panel b displays the prediction average for the 29 work-groups from 200 boostrap cycles (horizontal axis) in comparison to the observed follow up sickness absence rate (vertical axis). The size of each bubble corresponds to the number of subjects randomly chosen from each work-group’s participants for calculation of the prediction model