1947年，狄蘭·托馬斯創作了自己最著名的詩篇《不要溫柔走進那良宵》，勸誡讀者拒絕生命的盡頭。詩中寫道：“怒斥吧，怒斥光的消逝。”70年后，這種情緒在很大程度上激發了美國的醫藥投資。和其他經濟水平相當的國家相比，美國的健康開支要高得多，而且其中很大一部分都用在了老年人醫療保健上。2012年，年逾65歲的美國人的平均醫療保健支出為18988美元，是兒童平均開支的5倍，適齡勞動人口平均支出的3倍左右。這些資金成了美國健康花費整體趨勢的組成部分。2015年，美國健康總支出增長了5.8%，達到3.2萬億美元。

在如此巨大的投入之下，延長美國人壽命的手段層出不窮，而且往往為此利用基因和藥物創新。舉例來說，硅谷科技龍頭企業已經表露了“解決老化問題”和“改寫生命密碼”的意愿。吸引它們的是這樣一種可能性，即在恰當技術的幫助下，人類也許能獲得無限的壽命。

在本周的《財富》健康頭腦風暴大會上，我將從人口健康角度探討人們的長壽訴求，以下則是其中將要談到的一些想法。

100年來，人口預期壽命大大延長。1900年，美國的人口平均預期壽命約為47歲，如今則在79歲上下。但這樣的增長主要來自工業革命后公眾營養和生活水平的提升，以及公共健康領域的成就。雖然有了長足進步，但我們發現它們給人口預期壽命帶來的回報正在下降。無論我們多么渴望，人都無法永生。實際上，88%的美國人都活不到94歲，活不到100歲的占98%。新醫療手段確實有助于延長壽命，但作用有限。最近對健康技術評估報告的分析表明，2003-2013年，能延長整體存活期的癌癥治療新藥平均只能讓患者多活3.43個月。同時，在所有癌癥新藥中，已經證明可以延長存活期的不足20%。總的來說，基因或藥物創新對人類壽命的潛在提升幅度在100歲左右見頂，隨后迅速下滑，到115歲就不再起作用，這進一步證實人的壽命是有限的。

面對這樣的現實，我們怎樣才能在自己擁有的這段時間里提高生命質量呢？就像20世紀我們周圍的變化延長了人口預期壽命一樣，社會、經濟和環境條件的改善同樣能造就21世紀的幸福生活。舉例來說，在100萬人口的城市，如果交通系統擴張40%，健康成本就可下降2.16億美元。通過按環保標準改造住房，改善通風并減少對有害化學品的接觸，當地居民的生活質量就有望成倍提高。兒童早期教育的成本收益比為1比5。也就是說，在這方面花1美元帶來的益處，比如減少犯罪和少女懷孕，可節省5美元的支出。我們還可以通過漸進式稅制改革，特別是通過調整勞動所得稅抵扣幅度來大大造福人群。這個抵扣幅度每上調10%，美國每10萬名嬰兒的死亡率就會下降23.2名。

這些措施能讓我們朝著建設健康社會的方向大舉邁進。此前我們已經欣然接受了類似的做法，而且效果顯著。如今美國人的道路行程超過以往任何時候，但1925-1997年，美國的機動車交通事故死亡人數從每1億車英里18人降至1.7人。降低交通事故死亡人數的途徑是通過法律手段來阻止不安全駕駛行為，促進安全帶的使用以及修筑更安全的道路。簡而言之，我們已經通過改變駕駛環境和盡量減少危險提高了人們的健康水平。值得注意的是，我們在提高司機素質方面所做的少之又少，相反，我們改變了他們周圍的環境，從而讓所有人都更加安全。

這對我們建立更美好社會的思路格外重要。如果社會無視人們身邊決定幸福水平的因素，就算幸運到有錢和有資源的人也無法買到更健康的生活和更長的壽命。2010年以來，最多有5.6萬人死于流感，而這種疾病基本可以通過接種疫苗來預防。就是否患上流感而言，旁人的行為和我們自己的行為同樣重要。

在牙齒健康領域，如果不飲用添加氟化物的水，每1億美國人發生齲齒的風險就會上升15%。我們中間有多少人知道自己是否飲用了足夠的添加氟化物的水呢？超重人士的朋友變得超重的風險比其他人高57%。我們中間有多少人會根據對方是否超重來選擇朋友呢？無論是否喜歡，我們周圍的世界都在影響我們的健康。我們絕不可能通過花錢來擺脫社交網絡和政府政策，而后者決定著我們的幸福和壽命，因此這是我們共同的問題。

托馬斯在他的詩中描述了生命走到盡頭時的遺憾之情和錯失的良機。詩中所說的“日暮時咆哮”的人看到的并非不確定的未來，而是以往未能實現的承諾，或者說自己人生的質量。最終，起決定作用的是我們生命的豐富程度，是從幼到老的健康水平以及和周邊社區的聯系。要讓所有人都過上這樣的生活，我們就不能錯過對始終都在促進健康的文化進行投資的機會。（財富中文網）

譯者：Charlie

審稿：夏林

本文作者桑德羅·加利亞是波士頓大學公共衛生學院院長、Robert A. Knox講席教授。他的新書《更健康：關于人口健康基石的50個想法》（Healthier: Fifty thoughts on the foundations of population health）將于今年6月出版。

In 1947, Dylan Thomas composed his most famous poem, “Do not go gentle into that good night,” exhorting the reader to resist the end of life. “Rage, rage against the dying of the light,” Thomas wrote. Seventy years later, this sentiment infuses much of America’s investments in medicine. The US spends far more on health than any economically comparable country, with much of that money going towards healthcare for older Americans. In 2012, those over 65 years old spent an average of $18,988, which is more than five times the expenditure per child, and about three times the expenditure per working-age individual. This investment feeds into the broader trend of US health spending, which, in 2015, grew 5.8%, amounting to $3.2 trillion total.

Within the context of this enormous investment, we have seen the rise of a number of initiatives geared towards adding years to our lifespan, often leveraging genomics and pharmaceutical innovations toward this goal. Silicon Valley tech leaders, for example, have expressed a desire to “solve aging” and “hack the code of life,” enthralled by the possibility that, with the right technology, there may be no limit to how long we can live.

This week at Fortune’s Brainstorm Health conference, I will talk about the human quest for longevity viewed through the lens of population health. What follows is a preview, of sorts, of the thoughts I will be presenting there.

Life expectancy has increased significantly in the last century. In 1900, US life expectancy was about 47. It is now about 79. However, these gains were largely due to public improvements in nutrition and living standards precipitated by the Industrial Revolution, as well as to achievements in public health. Despite this remarkable progress, we are in the midst of seeing diminishing returns with respect to life expectancy. However much we might wish it were otherwise, we cannot live forever. Indeed, 88% of Americans will die before the age of 94, and 98% of Americans will die before the age of 100. It is true that new treatments can help prolong your life, but only to a limited degree. A recent analysis of health technology assessment reports found new cancer drugs to be associated with increased overall survival by an average of just 3.43 months between 2003 and 2013. Further, less than 20% of new cancer drugs have been proven to contribute to a survival increase. Overall, potential survival gains due to genetic or pharmaceutical innovation peak at about age 100, then quickly decline until the age of 115, adding more weight to the conclusion that the human lifespan is fixed.

Given this reality, how can we make life better during the time we have? Just as changes in the world around us contributed to rising life expectancy in the 20th century, improvement of these same social, economic, and environmental conditions can contribute to wellbeing in the 21stcentury. In a city of a million residents, for example, we could save $216 million in health costs through a 40% expansion of transit developments. We could double the quality of life for those living there by renovating housing according to green standards, improving ventilation, and reducing exposure to harmful chemicals. Early childhood education programs are associated with a benefit-cost ratio of 5:1, which means that for every dollar we spend on them we save five due to reductions in crime and teen pregnancy, among many other benefits. We could also do much good through progressive tax reform, especially by modifying the Earned Income Tax Credit (EITC). Each time the EITC has been raised by 10%, infant morality in the US dropped by 23.2 per 100,000 children.

Taking these steps would go far towards building a world that generates health. We have embraced similar measures in the past, to significant effect. In the US, we now travel more miles by road than ever before, yet in the years between 1925 and 1997, the nation decreased the number of motor vehicle deaths from a rate of 18 deaths per 100 million vehicle miles traveled to 1.7 deaths per 100 million miles traveled. The U.S. achieved this reduction by introducing legal disincentives for unsafe driving, promoting seatbelt use, and building safer roads. In short, we have improved health by changing the context around driving, minimizing hazard. It is worth noting that we did very little to improve the actual driver himself — rather, we changed the world around him, making us all safer.

This has particular importance for how we think of creating a better world. Even those of us who are lucky enough to have money and resources cannot buy ever-greater health and longer life in a society that neglects the conditions around us that determine wellbeing. Up to 56,000 people have died from the flu since 2010, a disease that is largely preventable through vaccines. Whether or not we get the flu depends as much on what those around us do as it does on our own actions.

In the area of dental health, risk of cavities increases by 15% for the 100 million Americans who do not drink fluoridated water. How many of us know whether we are drinking sufficiently fluoridated water? And our risk of becoming obese increases by 57% if we have a friend who becomes obese. How many of us choose our friends based on whether or not they are obese? The world around us therefore affects our health, whether we like it or not. It is simply not possible to buy our way out of the social networks and political policies that shape our wellbeing and our longevity, making this our shared issue.

In his poem, Thomas writes of the sense of regret and missed opportunities that can accompany the end of life. It is not to the uncertain future that his characters who “rave at close of day” look, but to the unfulfilled promise of the past — the quality of their years. What counts, in the end, is the richness of our lives, and the extent to which our time was healthy, and linked—from childhood to old age—to the community around us. To make this kind of life accessible to all, we must not miss our chance to invest in a culture that facilitates health throughout life.

Sandro Galea is the Robert A. Knox Professor and Dean of Boston University School of Public Health. His also author of the forthcoming book, Healthier: Fifty thoughts on the foundations of population health, which will publish in June.