Rehabilitation access and effectiveness cohort study for persons with back pain (REHAB-BP)

In cases of limited work ability or when work ability is at risk, people can apply for medical rehabilitation services. The German Pension Insurance provides these services with the aim of improving or restoring the ability to work. Musculoskeletal disease, especially back pain, is the main reason for medical rehabilitation. The appropriate access to rehabilitation according the actual needs of patients is currently under critical discussion. Frequently, the need for rehabilitation does not lead to a rehabilitation request. Despite the maxim 'rehabilitation before pension', every second person who receives a disability pension did not participate in rehabilitation services before the pension was granted. However, there are no up-to-date studies that have examined rehabilitation barriers. Moreover, randomised controlled trials that compared persons with and without rehabilitation participation have generated contradictory findings regarding the efficacy of medical rehabilitation. However, the setting of these studies was restricted to single centres or particular regions. There is currently no evidence on the effectiveness of rehabilitation services under routine conditions. The aim of our cohort study is twofold: first, to address barriers to the access to medical rehabilitation services in Germany, and second, to examine the effectiveness of German medical rehabilitation services by a propensity score matched analysis (Rehabilitation access and effectiveness cohort study for persons with back pain, REHAB-BP). The samples will be drawn from the registers of two pension insurance agencies (German Pension Insurance North: n = 22,500; German Pension Insurance Central Germany: n = 22,500). We will include employed people aged 45 to 59 years (stratified for sex and duration of sickness benefits). Persons who requested or utilised medical rehabilitation services during the past four years and persons with requested or approved disability pensions will be excluded. The baseline survey will be conducted in 2016. The questionnaire will assess the three-month prevalence of back pain, and will include a grading of pain severity and chronicity (level 0, grades I to IV). Furthermore, potential barriers to rehabilitation utilisation as well as the baseline scores of primary and secondary outcomes will be assessed. Utilisation of medical rehabilitation in 2016 and 2017 will be extracted from administrative data from the cooperating pension insurance agencies. A follow-up survey will be sent to back pain patients (grades I to IV; n = 5,760) in 2018 in order to evaluate the effects of rehabilitation utilisation (primary outcome: pain disability; secondary outcomes: e.g. pain intensity, disability days, work ability). Additionally, secondary outcomes will be extracted from administrative data (days with sickness benefits, days in employment subject to compulsory social insurance, disability pensions).

Of 45,000 members of the compulsory German Pension Insurance, 11,193 (24%) completed the baseline questionnaire in 2017. 6,940 individuals with back pain were followed up and received a second questionnaire in 2019. During the observation period 200 persons (3%) were treated in a medical rehabilitation programme due to musculoskeletal disorders including back pain.
Barriers to access were directly addressed in the questionnaire. The health status and associated limitations played a major role in the perception of a personal wish for rehabilitation. However, a considerable proportion of persons reported a lack of knowledge about medical rehabilitation services. The preliminary stage for submitting an application, i.e. developing an intention to apply, is mainly determined by contextual factors, particularly family and work-related barriers. In general, social support seems to be an important factor for preparing an application. A concrete intention to apply at baseline and aspects indicating restriction of participation were identified as determinants of the actual application. Even in a subgroup of 590 persons with severe back pain only 8.6% utilised a rehabilitation programme due to musculoskeletal disorders during the observation period.
For analysing the effectiveness of medical rehabilitation services, 200 persons treated in a medical rehabilitation programme were compared to 200 similar persons without rehabilitation. In the follow-up survey pain, health and work ability were reported more favourably by persons without rehabilitation. At first sight, the data suggest that rehabilitation was ineffective among employed persons with back pain. However, a very long mean period of more than 340 days was observed between the baseline survey and the start of the rehabilitation programme. In the meantime persons with rehabilitation may have experienced a health-related deterioration that led to their actual use of rehabilitation. Since the available data did not allow clarifying this point, we do not know if the sample characteristics at baseline reflect the characteristics of the treated persons at the beginning of their rehabilitation programme. Therefore, the non-suitability of the methodological approach in the study for analysing the effectiveness of medical rehabilitation became apparent during the course of the project.
These findings make an important contribution to the current scientific discussion on methodological approaches to testing the effectiveness of medical rehabilitation. In addition, new findings on barriers in the access to rehabilitation services enhance the existing data.