Are changes in Objective working hour characteristics associated with changes in work-life conflict among hospital employees working shifts? A 7-year follow-up

Objective: To investigate whether changes in objective working hour characteristics are associated with parallel changes in work-life conflict (WLC) among hospital employees. Methods: Survey responses from three waves of the Finnish Public Sector study (2008, 2012 and 2015) were combined with payroll data from 91 days preceding the surveys (n=2 482, 93% women). Time-dependent fixed effects regression models adjusted for marital status, number of children and stressfulness of the life situation were used to investigate whether changes in working hour characteristics were associated with parallel change in WLC. The working hour characteristics were dichotomised with cut-points in less than or greater than 10% or less than or greater than25% occurrence) and WLC to frequent versus seldom/none. Results: Change in proportion of evening and night shifts and weekend work was significantly associated with parallel change in WLC (adjusted OR 2.19, 95% Cl 1.62 to 2.96; OR 1.71, 95% Cl 1.21 to 2.44; OR 1.63, 95% Cl 1.194 to 2.22, respectively). Similarly, increase or decrease in proportion of quick returns (adjusted OR 1.45, 95% Cl 1.10 to 1.89) and long work weeks (adjusted OR 1.26, 95% Cl 1.04 to 1.52) was associated with parallel increase or decrease in WLC. Single days off and very long work weeks showed no association with WLC. Conclusions: Changes in unsocial working hour characteristics, especially in connection with evening shifts, are consistently associated with parallel chanqes in WLC.