Pain and mortality: mechanisms for a relationship

Moderate to severe chronic pain affects one in five adults and its impact increases with age. People with chronic pain that interferes with their lives have an increased risk of mortality. Identifying how interfering chronic pain can lead to mortality may highlight potential intervention strategies. This study uses a novel approach to test whether lifestyle, health, social and psychological factors mediate the relationship between pain and mortality.

Survival analyses (Cox’s proportional hazard modelling and a technique to assess mediation within survival models) were conducted on a large population study of adults aged ≥50 years from the English Longitudinal Study of Ageing (ELSA) (n=6324). Data collected at Wave 2 (2004) were used as baseline and follow-up was until 2012. The relationship between being “often troubled with pain” and mortality was examined. Lifestyle, health, social and psychological factors were tested as potential mediators.

The strongest mediating factors for the relationship between troubling pain and mortality were functional limitation (Hazard Ratio 1.31; 95%CI (1.20, 1.39)), symptoms preventing walking quarter of a mile (1.45 (1.35, 1.58)), physical inactivity (1.14 (1.10, 1.20)) and poor self-rated health (1.32 (1.23, 1.41)).

Mediators of the relationship between troubling pain and mortality provide targets for preventive health programmes. Interventions to improve general health, activity and function could improve long-term survival in patients with this clinical problem.