Are Global and Regional Improvements in Life Expectancy and in Child, Adult and Senior Survival Slowing?

Improvements in life expectancy have been considerable over the past hundred years. Forecasters have taken to applying historical trends under an assumption of continuing improvements in life expectancy in the future. A linear mixed effects model was used to estimate the trends in global and regional rates of improvements in life expectancy, child, adult, and senior survival, in 166 countries between 1950 and 2010. Global improvements in life expectancy, including both child and adult survival rates, decelerated significantly over the study period. Overall life expectancy gains were estimated to have declined from 5.9 to 4.0 months per year for a mean deceleration of -0.07 months/year2; annual child survival gains declined from 4.4 to 1.6 deaths averted per 1000 for a mean deceleration of -0.06 deaths/1000/year2; adult survival gains were estimated to decline from 4.8 to 3.7 deaths averted per 1000 per year for a mean deceleration of -0.08 deaths/1000/year2. Senior survival gains however increased from 2.4 to 4.2 deaths averted per 1000 per year for an acceleration of 0.03 deaths/1000/year2. Regional variation in the four measures was substantial. The rates of global improvements in life expectancy, child survival, and adult survival have declined since 1950 despite an increase in the rate of improvements among seniors. We postulate that low-cost innovation, related to the last half-century progress in health–primarily devoted to children and middle age, is reaping diminishing returns on its investments. Trends are uneven across regions and measures, which may be due in part to the state of epidemiological transition between countries and regions and disparities in the diffusion of innovation, accessible only in high-income countries where life expectancy is already highest.

近百年来，人类预期寿命的提升幅度相当可观。预测人员开始基于「未来预期寿命将持续提升」的假设，套用历史趋势开展预测。本研究采用线性混合效应模型（linear mixed effects model），对1950年至2010年间166个国家的全球及区域预期寿命提升率、儿童生存率、成人生存率与老年生存率的变化趋势进行估算。研究期内，全球整体预期寿命（涵盖儿童与成人生存率）的提升幅度显著放缓。经估算，整体预期寿命年均增幅从5.9个月降至4.0个月，平均减速幅度为-0.07个月/年²；儿童生存率年均新增避免死亡数从每千人4.4例降至1.6例，平均减速幅度为-0.06例/（千人·年²）；成人生存率年均新增避免死亡数从每千人4.8例降至3.7例，平均减速幅度为-0.08例/（千人·年²）；但老年生存率的年均新增避免死亡数却从每千人2.4例升至4.2例，平均增速为0.03例/（千人·年²）。上述四项指标的区域差异十分显著。尽管老年群体的寿命提升速率有所加快，但全球整体预期寿命、儿童生存率与成人生存率的提升速率自1950年以来均出现下滑。我们推测，与过去半个世纪卫生领域进展相关的低成本创新（主要聚焦儿童与中年群体），其投资回报正逐渐递减。不同区域与指标间的趋势存在显著不均，这一定程度上可能源于各国及各区域间的流行病学转型阶段差异，以及创新普及的不均衡——这类创新仅在预期寿命本就最高的高收入国家可及。