本文摘选自《柳叶刀》(The Lancet)，题目为Does happiness itself directly affect mortality? The prospective UK million women study，发表于2016年2-3月间。前人的研究认为，快乐与健康状况密切相关，不快乐可能会影响身体健康，增加死亡率。本文认为，前人的研究弄错了因果关系，健康状况不好可能会让人不快乐，而不快乐又可能导致如抽烟这样的不良生活方式。反过来，不良生活方式既会导致不快乐，又会导致较差的健康状况，不快乐和较差的健康状况是平行的，并非不快乐增加了死亡率，快乐与死亡率没有直接联系。请看文章摘要。
Background背景
Poor health can cause unhappiness and poor health increases mortality. Previous reports of reduced mortality associated with happiness could be due to the increased mortality of people who are unhappy because of their poor health. Also, unhappiness might be associated with lifestyle factors that can affect mortality.
健康状况不佳会导致不快乐，也会增加死亡率。前人的研究显示，死亡率降低与快乐相关，这可能是由于健康状况不佳既会让人感到不快乐，也会增加死亡率。而且，不快乐可能与影响死亡率的生活方式有关。
We aimed to establish whether, after allowing for the poor health and lifestyle of people who are unhappy, any robust evidence remains that happiness or related subjective measures of wellbeing directly reduce mortality.
不快乐的人的身体健康状况和生活方式可能也较差。在此前提下，本文还要确定是否仍然存在有力的证据证明快乐或相关的主观快乐指标直接降低了死亡率。
Method 方法
The Million Women Study is a prospective study of UK women recruited between 1996 and 2001 and followed electronically for cause-specific mortality.
这项“百万妇女研究”是对1996年至2001年间招募的英国女性进行的前瞻性研究，并通过电子方式追踪特定原因导致的死亡率。
3 years after recruitment, the baseline questionnaire for the present report asked women to self-rate their health, happiness, stress, feelings of control, and whether they felt relaxed.
招募3年后，本报告的基线调查问卷要求女性对自己的健康状况、快乐、压力、控制感以及是否感到放松作自我评价。
The main analyses were of mortality before Jan 1, 2012, from all causes, from ischaemic heart disease, and from cancer in women who did not have heart disease, stroke, chronic obstructive lung disease, or cancer at the time they answered this baseline questionnaire.
本文主要分析2012年1月1日之前妇女因各种原因导致的死亡率、因缺血性心脏病导致的死亡率以及因癌症导致的死亡率。在回答此基线调查问卷时，这些妇女没有心脏病、中风、慢性阻塞性肺病或癌症。
We used Cox regression, adjusted for baseline self-rated health and lifestyle factors, to calculate mortality rate ratios (RRs) comparing mortality in women who reported being unhappy (ie, happy sometimes, rarely, or never) with those who reported being happy most of the time.
我们根据基线自评健康和生活方式因素调整Cox回归分析，以计算死亡率比率（RR），比较不快乐（有时、很少或从不快乐）女性与大多数时间都快乐的女性的死亡率。
Findings结果
Of 719 671 women in the main analyses (median age 59 years [IQR 55–63]), 39% (282 619) reported being happy most of the time, 44% (315 874) usually happy, and 17% (121 178) unhappy.
主要分析中共有719671名女性（中位年龄59岁[IQR 55-63]），其中有39％（282619）大部分时间都很快乐，44％（315874）通常都快乐，17％（121178））不快乐。
During 10 years (SD 2) follow-up, 4% (31 531) of participants died. Self-rated poor health at baseline was strongly associated with unhappiness.
在10年（SD 2）随访期间，4％（31531）参与研究的女性死亡。调查时自评较差的健康状况与不快乐有很强的相关性。
But after adjustment for self-rated health, treatment for hypertension, diabetes, asthma, arthritis, depression, or anxiety, and several sociodemographic and lifestyle factors (including smoking, deprivation, and body-mass index), unhappiness was not associated with mortality from all causes (adjusted RR for unhappy vs happy most of the time 0·98, 95% CI 0·94–1·01), from ischaemic heart disease (0·97, 0·87–1·10), or from cancer (0·98, 0·93–1·02). Findings were similarly null for related measures such as stress or lack of control.
但在调整自评健康，调整高血压、糖尿病、哮喘、关节炎、抑郁或焦虑治疗，以及调整一些社会人口和生活方式因素（包括吸烟、剥夺和体重指数）后，不快乐与各种原因（大多数时候，不快乐对快乐的调整后RR为0.98, 95％CI 0.94-1.01）导致的死亡率、因缺血性心脏病（0.97, 0.87-1.10）或癌症（0.98, 0.93-1.02）导致的死亡率都无关。对于压力或缺乏控制等相关指标，结果同样为零。
Interpretation 讨论
In middle-aged women, poor health can cause unhappiness. After allowing for this association and adjusting for potential confounders, happiness and related measures of wellbeing do not appear to have any direct effect on mortality.
在中年妇女中，健康状况不佳会导致不快乐。在考虑这种关联并调整潜在的混杂因素后，发现快乐及相关的快乐指标对死亡率没有直接影响。
