The scale contains 11 dichotomous items, representing short-term effects of a day of work. All items were recoded in such a way that higher scores indicate ‘more complaints’, i.e. a higher need for recovery. The recoded scores are presented C646 cost in a range from 0 to 100. The Cronbach’s alpha of the scale is 0.78 (Jansen et al.

2002). Examples of items in the scale are ‘I find it hard to relax at the end of a working day’ and ‘Because of my job, at the end of the working day, I feel rather exhausted’ (Van Veldhoven and Broersen 2003). In the present study, the upper quartile was used to define a contrast between employees with a high versus low-medium need for recovery, which corresponds with a cut-off point of 6 on the 11-item scale as recommended by Broersen et al. (Broersen Paclitaxel manufacturer et al. 2004). The level of need for recovery was determined in each questionnaire (T0, T1, T2, T3, T4, T5, T6). Demographic and health factors Employees provided information on gender, age, educational level and the presence of a long-term illness through self-report in the questionnaires. Employees were divided into five age groups, that is, 18–25, 26–35, 36–45, 46–55 and 56–65 years. Smoking

status was assessed by a single dichotomous item (“Do you smoke every day?”). Characteristics of the private situation Living situation was operationalized as living alone (yes/no). Work–family conflict was measured by one dichotomous item asking employees whether they were able to adequately combine work and family life. Work characteristics Regarding working hours, employees were amongst others asked for their working hours per week, categorized as >40, 36–40, 26–35, 16–25 and <16 h per week. Also, information on overtime was collected using an item on frequent overtime

(yes/no). A Dutch version of the Job Content Questionnaire was used to measure psychological job demands and decision latitude (Karasek 1985). Psychological job demands were assessed by the sum of five items (Chronbach’s alpha 0.69). Decision latitude (Chronbach’s alpha 0.81) was measured by the sum of two subscales: skill discretion and decision authority. The response options BCKDHA varied from “strongly disagree” to “strongly agree” on a four-point scale. The total score was then divided into tertiles, resulting in low, medium and high levels of psychological job demands or decision latitude. To assess whether employees perceived their work as physically demanding, one item of the Dutch questionnaire on Work and Health (VAG; Gründemann et al. 1993) was used. Statistical analysis Because the distribution of need for recovery was skewed to the left, Poisson regression analyses were conducted to test differences in mean levels of need for recovery in the cross-sectional analyses.