This study confirms that it is a great challenge to re-enter work after becoming a disability pensioner. Of 899 disability pensioners with musculoskeletal disorders, only 1 single person had returned to full time work, while 14 had small reductions in payment of DP at 3-year follow-up. This result also included a group of disability pensioners who had participated in a previous cognitive behavioural program with a vocational approach. Despite a positive trend regarding progress towards work after 1 year, none of these individuals actually returned to work within the next 2 years. The poor results are in line with other reports on re-employment efforts among disability pensioners [8, 17].
Despite no effect in the main outcome, the initial conclusion after 1-year follow-up suggested a modest success as several participants reported to have entered into a work-related process. We expected that a proportion of the participants who had been in such a process would actually have returned to work at the 3-years follow-up. This assumption is supported by findings in other studies showing a moderate effect of brief interventions in terms of returning sick listed persons with back pain to work [18, 19]. However, no previous studies have examined long-term effects of intervention programmes directed towards disability pensioners. Therefore, the present study was carried out to examine whether an intervention would bring on a more permanent or even increased effect in the long run. The negative result of the 3-years follow-up was therefore an important, but rather disappointing finding.
Work-related interventions for this chronic group should maybe have been more extensive and individually adjusted than the brief intervention we offered. A strategy based on a closer collaboration with possible work places, and a more comprehensive program in general, including more extensive support from all parts involved in the process, might have increased the success rate. Another important factor for success in this field is the individual's positive beliefs and expectancy regarding recovery and employment [20–22]. Previously, we have reported that a majority of the disability pensioners had negative beliefs regarding returning to work . In a qualitative study of the same population we found indications that negative beliefs were linked to earlier negative experiences with the workplace. These experiences included lack of willingness from management and colleagues to make work adjustments . In addition, uncertainties about future health, financial consequences and work skills have also been reported as barriers against returning to work [10, 24]. Identifying these barriers and directly addressing them in the intervention programmes, may increase the likelihood of re-entering work .
Pensioners being in a work related process might have experienced only a small, if any, increase in income, and this fact has been described as de-motivating . A more substantial increase in income may result in a better motivation and more lasting effects. In Norway, disability pensioners are allowed to earn a limited income without any reduction in DP, and some will cope well within this frame of activity. The present study was solely based on insurance data, and therefore we do not know if any pensioners had obtained this additional income. As Norway has a very generous DP , our results might not be comparable to other countries where being employed yields a larger economic benefit.
Failure of lasting results might also be due to the insurance policy. An initial attempt to try out for work will often be made with economic support from the social insurance offices. Transformation to a permanent job paid for by an employer has been shown to be difficult, as employers prefer to hire employees without a history of sick leave and disability if given the option.
We found no difference in long time re-employment between different diagnostic groups or between intervention and control groups. Neither age, gender, time upon DP, nor being submitted to intervention or not, seemed to influence the negative result. We found a difference between the groups regarding duration of DP varying from 9.8 to 11 years, but this small difference has probably no practical impact. We regard the long time span of disability in itself as the main obstacle to a successful return to work, not the diagnosis or vocational interventions provided. It is tempting to speculate whether the pensioners concluded that they were comfortable with their life situation as it was. Most have many health complaints  and may consider working life as too demanding, and was therefore, after several years, have come to acceptance with their situation. In a previous study, pensioners expressed that they appreciated the safety of the DP, and were reasonably satisfied with their life situation .
We used reduction in payment of DP as an indicator of having returned to work. If disability pensioners exceed the limit of income he or she is allowed to earn, the pension will be reduced correspondingly. In Norway will be no other reason for the pension to be reduced or removed. Thus, we could assume that a reduction in DP payment meant that the pensioner earned more than the allowed amount. A possible limitation in our study was that we did not have access to more detailed information about the pensioners. We do not know whether the 3 study groups were comparable regarding factors like expectancy, level of education and previous occupation. Also, considering the small number of participants who had entered a return to work process after 1 year, we find that a qualitative study outlining the pensioners' experiences of the unsuccessful return to work process could have yielded additional important information to the outcome.