Three occupational health services were invited to participate in the ADAPT study. Two occupational health services responded positive. The remaining one responded with substantial doubts related to the time investment for the OH professionals. The researchers therefore decided to proceed with the two positive occupational health services, which were connected to three large companies from the industrial, health care, education, and research sectors (n ≈ 20.000 employees).
Of the 13 RTW coordinators who were invited for training in the workplace intervention, one was not motivated before and one did not feel capable to conduct the intervention after participating in the training. Due to slow recruitment rates, one RTW coordinator decided during the course of the study not to continue with the intervention and another one retired before a first participant was referred to her. All 14 OPs from the participating occupational health services participated in the ADAPT study.
Figure 2 shows the flow diagram of employees in the ADAPT study. Approximately, 8,500 screeners were sent to sick-listed employees. Based on the screeners that were returned, 744 employees were eligible for participation in the study. When 568 were contacted by phone, 456 were unwilling to participate or could not participate for other reasons. The main reason for non-participation (41%) was a RTW or RTW planned within 2 weeks. Other reasons for non-participation were most frequently related to the intervention (time-restrictions, burden, satisfied with current treatment) and the reason for sick leave (private problems, elective surgery). In fact, 298 (65.4%) employees could not participate and 158 (34.6%) employees refused to participate. Finally, 112 participants were randomised. There were no differences in age or gender between participants and non-participants. However, excluding the employees who returned to work, men were more likely to participate than women (P = 0.005). Of those randomised to the intervention group (N = 56), 40 actually started participating in the intervention and their data were used for this study. The baseline characteristics of those employees are shown in Table 1.
Implementation of the Workplace Intervention
Among the employees in the intervention group, the most often reported reason for not starting to participate in the intervention was RTW; four employees returned to their previous job and three employees returned to a new job. Other reasons are shown in Fig. 2. One employee started participating in the intervention but neither the employee nor the supervisor could identify obstacles for RTW. Therefore, complete protocol implementation was eventually accomplished for 39 employees. For three participants there was no evaluation of the realization of solutions by phone. Optional meetings for instructions at the workplace took place seven times, and additional meetings with the RTW coordinator took place six times.
Timeline and Duration of the Workplace Intervention
The time schedule for starting the intervention was properly followed. However, the first three meetings were not all planned on 1 day for 17 of the 39 participants. For those 17 employees the median time between the three meetings was 12 calendar days (IQR 3–23 days). The median time between the workplace intervention meetings and the evaluation was 56 calendar days (IQR 38–87 days) for the 36 employees for whom an evaluation was conducted. The intervention manual described a 1 month period between the meetings and the evaluation. The delay that occurred was due to RTW coordinator preferences or a delayed visit to the workplace. In total, the three meetings (of the RTW coordinator with the employee, the supervisor, and the employee and supervisor together) lasted for an average of 3 h and 45 min. The median time investment for the complete workplace intervention for the RTW coordinator was 7 h (IQR 5.5–8.4 h), including the time needed for administration.
Implementation of the Workplace Intervention Process
The RTW coordinators and OPs reported that, respectively, 89–92% of the 40 employees were cooperative regarding participation in the workplace intervention. Over 60% of the employees actively participated, according to the RTW coordinators. The supervisors were also cooperative in 84% of the cases, according to the OPs. From the RTW coordinators point of view, 98% of the employees had a sufficient say in the workplace intervention process.
A total of 151 obstacles for RTW were identified, most of which were related to job design (13% of all obstacles), communication (13%), mental workload (17%), physical workload (10%), and person-related stress factors (22%), such as perfectionism and a high sense of responsibility. Subsequently, 281 solutions for RTW were identified and those most frequently mentioned are presented in Fig. 3. Most of the solutions were classified into the categories of job design (e.g., task rotation, skip task temporarily), communication (e.g., feedback from supervisor, regular meetings with supervisor) and training (e.g., time management, skills training). The highest priority obstacles and solutions showed very similar results: the highest priority obstacles were mental workload (16% of all obstacles) and person-related stress factors (24%); the highest priority solutions were communication (20% of all solutions) and training (20%).
In 56% of the 281 solutions the person responsible for the initiation of actions was the employee and in 36% it was the supervisor. Seventy five percent of the solutions could be realized in the short-term (within 3 months), but for 16% of the solutions no clear timeline could be indicated, for instance if a solution could only be realized after actual RTW. The evaluation showed that 72% of the solutions were realized according to the employee and the supervisor. Of the 281 solutions, 28% had not been realized at the time of evaluation, in 10% of the solutions because another solution was found, and in 2% of the solutions because a new obstacle for RTW was experienced by the employee and as a consequence the initial solution was inappropriate. Of the obstacles (N = 37) and solutions (N = 66) with the highest priority, ~70% were realized at the time of the evaluation, according to the employee and the supervisor.
Barriers and Facilitators for the Realization of the Solutions
With regard to realization of the solutions, the relationship between the employee and the supervisor, the employee’s motivation to work, and the opportunities for work adaptation were most often rated as facilitating factors. Mentally demanding work and the mental capacity of the employee were considered by the OH professionals to be barriers for the realization of solutions.
Barriers and Facilitators for the Implementation of the Workplace Intervention
After each workplace intervention, OH professionals rated the factors that impeded and facilitated the process of the workplace intervention. Compliance, commitment, and influence of both the employee and the supervisor were regarded as the most important factors that were positively related to the process of the intervention.
On a broader level, OH professionals rated the presence of various implementation factors for the workplace intervention (Table 2). Except for time investment and scientific basis, all factors were clearly rated as present, and therefore influenced implementation positively. With regard to the timing of the start of the intervention, immediate application when sick leave occurs was recommended by 8 of the 18 OH professionals, because in the ADAPT study the intervention was sometimes applied too late to be of any use. Finally, the standardized matrices were considered to be too extensive.
Satisfaction, Usefulness and Expectations
The workplace intervention was expected by most OPs and RTW coordinators to have no effect on time until RTW (respectively, for 60 and 54% of the 40 employees). Sustainable RTW was expected to be positively influenced by the intervention for, respectively, 55–74% of the employees. More than half of the employees and two-thirds of the supervisors expected the intervention to have positive effects on RTW. Even though the workplace intervention focused on RTW, the expectations of the OPs with regard to recovery of symptoms were positive for almost one-third of the employees. The usefulness of the workplace intervention and satisfaction with the work adaptations were most frequently rated positively by the employees and the supervisors (Fig. 4).
The OH professionals were satisfied with the process of the workplace intervention and rated this on average as 7.1 (scale 1–10; 10 indicating maximum satisfaction). Being taken seriously by the OP and the RTW coordinator was positively rated by the employees as a score of 3.4 and 3.9, respectively, (scale 1–5; 5 indicating maximum). The presence of the RTW coordinator was viewed as a positive influence on feelings of safety and support, according to employees and RTW coordinators, whereas the supervisors and RTW coordinators thought that it led to less perceived differences in authority between employees and supervisors.
All 18 OH professionals reported that they intended to refer to or apply the workplace intervention in the future. Application of the intervention by RTW coordinators was preferred because the intervention is too time consuming for OPs. Application of the intervention was favored for communication problems, work-related barriers for RTW, passive or non-assertive employees, and stagnation of RTW. Application was considered to be inappropriate for actual conflicts at work (without legal involvement), good communication about RTW between the employee and the supervisor, and non-work-related problems (just personal problems).