A longitudinal study of changes in interactional justice and subsequent short-term sickness absence among municipal employees.

Objectives Level of perceived interactional justice has been shown to be associated with sickness absence, but less is known about the effects of changes in interactional justice. It is also unknown to what extent unmeasured, time-invariant differences contribute to the association. We investigated the association between interactional justice changes and subsequent short-term (1-3 days) sickness absences over a 12-year follow-up using between- and within-individual modeling among ageing municipal employees. Methods The data was derived from Helsinki Health Study cohort with baseline survey in 2000-2002 (N=8960, response rate 67%) and follow-up surveys in 2007 and 2012 (response rates 79% and 83%, respectively). At baseline, participants were 40-60-year-old employees of the City of Helsinki, Finland. Sickness absences from the employer's registry were linked with the responses (78%). The analytic sample was 2109 and 2070 individuals for between-individual and 4433 individuals and 8425 observations for within-individual associations. Results Negative change in interactional justice was associated with an increased risk of short-term sickness absence in between-individual models after adjusting for age and gender. Adjustment for sickness absence history attenuated the association. In within-individual models, a negative change in perceived interactional justice was associated with an increased risk of short-term sickness absence spells [incidence rate ratios (IRR) 1.05 (95% confidence interval 1.01-1.09)]. This association was robust to adjustments for gender, age, health behaviors and sickness absence history. Conclusions Paying attention to management principles - especially managerial behavior and treatment of employees to avoid the deterioration of the level of interactional justice - may provide a way of reducing self-certified short-term sickness absence spells.