Der Geoff, Deary Ian J
MRC/CSO Social and Public Health Sciences Unit, University of Glasgow, UK.
Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, UK.
Intelligence. 2018 Jul-Aug;69:134-145. doi: 10.1016/j.intell.2018.05.005.
The association of premorbid cognitive ability with all-cause mortality is now well established. However, since all-cause mortality is relatively uninformative about aetiology, evidence has been sought, and is beginning to accumulate, for associations with specific causes of mortality. Likewise, the underlying causal pathways may be illuminated by considering associations with different measures of cognitive ability. For example, critics of IQ type measures point to possible cultural or social biases and there is, consequently, a need for more culturally neutral measures such as reaction times. We examine the associations of cognitive ability with major causes of mortality, including: cardiovascular disease, cancer and respiratory disease and compare the results for a standard IQ test, the Alice Heim 4 (AH4), with those for simple and four-choice reaction times.
Data were derived from the oldest cohort of the West of Scotland Twenty-07 Study. Participants were randomly sampled from the Central Clydeside Conurbation, a mainly urban area centred on Glasgow city. At baseline, aged 56, they were interviewed in their homes by trained interviewers; the AH4 was administered and reaction times measured using a portable electronic device. Vital status was ascertained via linkage to the NHS central register. Cox regression was used in SAS 9.4 for the main analyses. Adjustments were made for sex, smoking status and social class.
Full data on AH4, RT and covariates were available for 1350 out of 1551. During 29 years of follow-up, there were 833 deaths: 279 cardiovascular disease (CVD) (168 CHD; 68 stroke); 291 cancer; 97 respiratory disease; 42 digestive disease; and 39 dementia. The 85 remaining deaths were a heterogeneous mixture with no cause accounting for more than 14.AH4 scores were associated with most major causes. Digestive disease and dementia had similar effect sizes but were not significant. Within cardiovascular disease, there was an association with coronary heart disease but not stroke. The association with cancer was primarily due to those cancers related to smoking.RT measures were mostly associated with the same causes of death. Where significant, effects were in the same directions and of similar magnitude. That is, lower AH4 scores, longer reaction times, and more variable reaction times were all associated with increased mortality risk from the major causes of death. A summary measure of RT outperformed the AH4 for most causes.
The association between intelligence with mortality from the major causes is also seen with reaction times. That effect sizes are of similar magnitude is suggestive of a common cause. It also implies that the association of cognitive ability with mortality is unlikely to be due to any social, cultural or educational biases that are sometimes ascribed to intelligence measures.
病前认知能力与全因死亡率之间的关联现已得到充分证实。然而，由于全因死亡率对于病因的信息相对较少，因此人们一直在寻找并开始积累与特定死亡原因相关的证据。同样，通过考虑与不同认知能力测量指标的关联，可能会揭示潜在的因果途径。例如，智商类型测量的批评者指出可能存在文化或社会偏见，因此需要更具文化中立性的测量指标，如反应时间。我们研究了认知能力与主要死亡原因之间的关联，包括心血管疾病、癌症和呼吸系统疾病，并比较了标准智商测试爱丽丝海姆4（AH4）的结果与简单反应时间和四选一反应时间的结果。
数据来自苏格兰西部20-07研究中最老的队列。参与者是从以格拉斯哥市为中心的主要城市地区中央克莱德赛德聚居区随机抽取的。在基线时，他们56岁，由训练有素的访谈员在其家中进行访谈；进行了AH4测试，并使用便携式电子设备测量反应时间。通过与国民保健服务中央登记处的链接确定生命状态。在SAS 9.4中使用Cox回归进行主要分析。对性别、吸烟状况和社会阶层进行了调整。
1551名参与者中有1350名获得了关于AH4、反应时间和协变量的完整数据。在29年的随访期间，有833人死亡：279人死于心血管疾病（CVD）（168人死于冠心病；68人死于中风）；291人死于癌症；97人死于呼吸系统疾病；42人死于消化系统疾病；39人死于痴呆症。其余85例死亡是异质性混合，没有任何一种原因占比超过14。AH4分数与大多数主要原因相关。消化系统疾病和痴呆症的效应大小相似，但不显著。在心血管疾病中，与冠心病有关，但与中风无关。与癌症的关联主要是由于那些与吸烟有关的癌症。反应时间测量大多与相同的死亡原因相关。在显著的情况下，效应方向相同且大小相似。也就是说，较低的AH4分数、较长的反应时间和更易变的反应时间都与主要死亡原因导致的死亡风险增加相关。对于大多数原因，反应时间的综合测量指标比AH4表现更好。
反应时间也显示出智力与主要原因导致的死亡率之间的关联。效应大小相似表明存在共同原因。这也意味着认知能力与死亡率之间的关联不太可能是由于有时归因于智力测量的任何社会、文化或教育偏见。
