Chronic pain is a serious and prevalent condition that can affect many facets of life. However, uncertainty remains regarding the strength of the association between chronic pain and death and whether the association is causal. We investigate the pain-mortality relationship using data from 19,971 participants aged 51+ years in the 1998 wave of the U.S. Health and Retirement Study. Propensity score matching and inverse probability weighting are combined with Cox proportional hazards models to investigate whether exposure to chronic pain (moderate or severe) has a causal effect on mortality over a 20-year follow-up period. Hazard ratios (HRs) with 95% confidence intervals (CIs) are reported. Before adjusting for confounding, we find a strong association between chronic pain and mortality (HR: 1.32, 95% CI: 1.26-1.38). After adjusting for confounding by sociodemographic and health variables using a range of propensity score methods, the estimated increase in mortality hazard caused by pain is more modest (5%-9%) and the results are often also compatible with no causal effect (95% CIs for HRs narrowly contain 1.0). This attenuation highlights the role of confounders of the pain-mortality relationship as potentially modifiable upstream risk factors for mortality. Posing the depressive symptoms variable as a mediator rather than a confounder of the pain-mortality relationship resulted in stronger evidence of a modest causal effect of pain on mortality (eg, HR: 1.08, 95% CI: 1.01-1.15). Future work is required to model exposure-confounder feedback loops and investigate the potentially cumulative causal effect of chronic pain at multiple time points on mortality.

中文翻译：

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慢性疼痛和死亡之间的关系是因果关系吗？倾向得分分析。


慢性疼痛是一种严重且普遍的疾病，会影响生活的许多方面。然而，关于慢性疼痛与死亡之间关联的强度以及这种关联是否是因果关系，仍然存在不确定性。我们使用 19,971 年美国健康与退休研究浪潮中 51+ 岁的参与者的数据调查了疼痛与死亡率的关系。倾向评分匹配和逆概率加权与 Cox 比例风险模型相结合，以研究暴露于慢性疼痛（中度或重度）是否对 20 年随访期间的死亡率有因果影响。报告了风险比 （HRs） 和 95% 置信区间 （CIs）。在调整混杂因素之前，我们发现慢性疼痛与死亡率之间存在很强的相关性 （HR： 1.32， 95% CI： 1.26-1.38）。在使用一系列倾向评分方法按社会人口学和健康变量调整混杂因素后，估计的疼痛引起的死亡风险增加更温和 （5%-9%），并且结果通常也与无因果效应相容 （HR 的 95% CI 勉强包含 1.0）。这种衰减突出了疼痛-死亡率关系的混杂因素作为潜在可改变的死亡上游危险因素的作用。将抑郁症状变量作为疼痛-死亡率关系的中介而不是混杂因素，导致更有力的证据证明疼痛对死亡率的适度因果影响（例如，HR：1.08,95% CI：1.01-1.15）。未来的工作需要对暴露混杂因素反馈回路进行建模，并研究慢性疼痛在多个时间点对死亡率的潜在累积因果影响。