A prospective study in the US showed that optimism was associated with lower mortality of numerous causes. The study evaluated the association between optimism and cause-specific mortality in 70021 women using Cox proportional hazard models. Dispositional optimism was measured in 2004; all-cause and cause-specific mortality rates were assessed from 2006 to 2012. A higher degree of optimism was associated with a lower mortality risk. After adjustment for sociodemographic confounders, compared with women in the lowest quartile of optimism, women in the highest quartile had a hazard ratio of 0.71 for all-cause mortality. Adding health behaviors, health conditions, and depression attenuated but did not eliminate the associations (hazard ratio = 0.91). Associations were found for various causes of death, including cancer, heart disease, stroke, respiratory disease, and infection. It has been demonstrated in randomized trials that optimism can be learned. Source: http://aje.oxfordjournals.org/美国的前瞻性研究表明，乐观与许多原因的死亡率降低有关。该研究用Cox比例风险模型对70021名妇女评估了乐观与特异原因死亡率之间的关系。 2004年测量了乐观气质; 2006年至2012年评估了全因和特异原因死亡率。较高程度的乐观与较低的死亡风险相关。经校正社会人口混杂因素后，与最低四分位数乐观度的妇女相比，最高四分位数乐观度妇女全因死亡率的风险比为0.71。加上健康行为，健康状况和抑郁症后该相关关系减轻而未消除（风险比= 0.91）。发现了与各种死因的关联，包括癌症，心脏病，中风，呼吸道疾病和感染。随机试验已证明可以学得乐观些。来源：http://aje.oxfordjournals.org/
