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[Concerning the impact of psychological comorbidity for chronic back pain: frequency, reduced earning capacity pension and rehabilitation aftercare in the course of the rehabilitation cohorts 2002–2009].

BACKGROUND AND OBJECTIVE
Psychological comorbidities play a key role in the chronification process of back pain. The aim of this longitudinal study is to analyze the diagnostics of psychological comorbidities, their influence on back pain patients and the recommendations of aftercare over the course of time.


METHODS
A descriptive analysis of diagnosed psychological comorbidities for the rehabilitation cohorts from 2002 to 2009 was conducted as well as a modelling of Poisson regressions to calculate relative risks and incidence rates.


RESULTS
The frequency of at least one psychological comorbidity ranges from 17.6 to 17.9% in the years 2002–2004 and from 18.9 to 20.9% in the years 2005–2009. The risk of reduced earning capacity pension for persons with a comorbid psychological disorder is increasing significantly in almost all rehabilitation cohorts regardless of gender and adjusted for other risk factors compared to persons without comorbid psychological disorders. The number of recommended aftercare procedures is increasing over all cohorts:starting in 2005 with less than 5% of patients to every fourth patient with an aftercare recommendation in 2009.


CONCLUSION
The frequencies of psychological comorbidities as reported in the discharge letters for the cohorts of patients in rehabilitation are below the reported frequencies of epidemiological studies. Psychological comorbidities have a considerable impact on pension for reduced earnings capacity. This finding could be useful for recommending aftercare programs.