Lifestyle and psychologic factors, and paina meta-analysis and cohort study

Abstract

Chronic pain is one of the leading causes of healthcare seeking. Chronic pain is the main contributor to years lived with disability (YLDs) worldwide and represents a considerable economic burden due to healthcare expenses and lost productivity. However, chronic pain has long been considered a symptom of other diseases and not an independent pathological condition. This has contributed to the undervaluation of this entity by health professionals. Recently, an International Association for the Study of Pain (IASP) Task Force was instrumented to add a code for chronic pain to the ICD-11, to support the fact that chronic pain is a disease entity “in its own right”. Therefore, in this thesis, we decided to assess the role of lifestyle and psychological factors in the incidence of chronic pain among the young population. In this thesis, we used dose-response meta-analysis techniques to answer the question of whether alcohol intake is related to chronic pain occurrence. We analyzed three case-control and thirteen cohort studies that were eligible to be included in the meta-analysis. The results showed a decreased risk of chronic pain among people who drank alcohol. In addition, we found a non-linear association between alcohol consumption and chronic pain in the dose-response meta-analysis. Also, we evaluated the direct and indirect effects of depression on pain through sleep disturbance using a two-stage meta-analytic structural equation modeling. With a comprehensive search strategy, we found sixty-four case-control and cohort studies eligible for the meta-analysis. The results showed a partial mediation effect of sleep disturbance on the relationship between depression and pain among some subgroups, including chronic pain outcomes, cohort design, studies carried out in the general population, and high-quality studies. We conducted a cohort study on the students of the University of Santiago de Compostela to evaluate the effect of health-related quality of life or well-being as a biopsychosocial factor on chronic pain incidence. In the first part of this cohort study, we assessed the association between physical and mental components of health-related quality of life (well-being) on chronic pain incidence. High scores of physical health-related quality of life were related to a decrease in chronic pain incidence; however, no association was observed between mental health-related quality of life and chronic pain. In the second part of this cohort study, we assessed the causal role of covariates in the association between physical well-being and chronic pain. We applied mediation analysis to find potential mediators and stratum-specific techniques to find and distinguish potential confounders from interactors. The results showed that perceived stress had a mediation role, physical activity and alcohol drinking had a significant role as interactors, and smoking was a potential confounder and interactor of the association between physical well-being and chronic pain. The different biological mechanisms can explain the results of these findings; however, we considered some concepts as alternative explanations in our interpretation, such as reverse causality and misclassification