Chronic pain in the United Kingdom and associated cardiovascular disease

Abstract

Prior to the studies presented in this thesis there was no widely accepted estimate for the prevalence of chronic pain in the United Kingdom, little understanding of the biological consequences of chronic pain (as compared to its psychological and social impact), and unresolved issues about the possible influence of chronic pain on cardiovascular outcomes. I have used meta-analysis to summarise prevalence estimates for a range of chronic pain phenotypes, demonstrating that just over 43% of the adult population experience pain with a duration of 3 months or greater. This figure is considerably higher than estimates often quoted in public and scientific forums. I have also outlined the impact of chronic pain on cardiovascular health through a systematic review of existing evidence, suggesting that chronic pain may be associated with cardiovascular disease and cardiovascular mortality. However, existing studies took an inconsistent and incomplete approach in their adjustment for potentially confounding factors, so it cannot be concluded that these associations are causal. I have therefore supplemented existing evidence with analysis of data from a large national survey of the population of England, adjusting for a comprehensive list of potentially confounding variables. My study shows that participants reporting chronic pain are 55% more likely to experience cardiac disease than those without pain, and that this risk increases systematically in-line with increasing chronic pain intensity. In summary, I have demonstrated that chronic pain affects a much greater proportion of the adult population on the United Kingdom than previously estimated. Furthermore, adults reporting chronic pain, in particular those most severely affected, may be at significantly increased risk of cardiac disease. Future studies should focus on determining whether reducing the impact of chronic pain can improve cardiac health.