Background and objectives: The relationship between somatic and psychiatric comorbidity in patients with somatic diseases and diverse outcome variables like mortality, costs, and duration of treatment is often examined and confirmed. In the last years, quality of life (QoL) as another important outcome variable received more attention.
Methods: The present review comprises a summary of associations between comorbidity and QoL in patients with somatic diseases. For this reason a search for somatic diseases was performed, including metabolic, respiratory tract, musculoskeletal, cardiovascular, cancer, digestive system, and general somatic diseases. Four hundred eighty-one studies were found, of which 45 fulfilled the inclusion criteria.
Results: Overall, there are mostly significant negative correlations between comorbidity and QoL. Predominantly, this applies to somatic-psychiatric comorbidity, which accounts for 70.3% (psychosocial aspects of QoL) to 100% (QoL in general) significantly lowered QoL results. Somatic-somatic comorbidities are primarily associated with somatic aspects of QoL (56.5-80.7% significant results), while psychosocial aspects as well as QoL in general are significantly associated in 8.3% to 71.7% of all calculations.
Conclusion: It is of high relevance for life quality research and clinical practice to pay attention to comorbidity. Methodological shortcomings should be taken into account in future research.