Social determinants of adult mortality from non-communicable diseases in northern Ethiopia, 2009-2015: Evidence from health and demographic surveillance site

IntroductionIn developing countries, mortality and disability from non-communicable diseases (NCDs) is rising considerably. The effect of social determinants of NCDs-attributed mortality, from the context of developing countries, is poorly understood. This study examines the burden and socio-economic determinants of adult mortality attributed to NCDs in eastern Tigray, Ethiopia.MethodsWe followed 45,982 adults implementing a community based dynamic cohort design recording mortality events from September 2009 to April 2015. A physician review based Verbal autopsy was used to identify the most probable causes of death. Multivariable Cox proportional hazards regression was performed to identify social determinants of NCD mortality.ResultsAcross the 193,758.7 person-years, we recorded 1,091 adult deaths. Compared to communicable diseases, NCDs accounted for a slightly higher proportion of adult deaths; 33% vs 34.5% respectively. The incidence density rate (IDR) of NCD attributed mortality was 194.1 deaths (IDR = 194.1; 95% CI = 175.4, 214.7) per 100,000 person-years. One hundred fifty-seven (41.8%), 68 (18.1%) and 34 (9%) of the 376 NCD deaths were due to cardiovascular disease, cancer and renal failure, respectively. In the multivariable analysis, age per 5-year increase (HR = 1.35; 95% CI: 1.30, 1.41), and extended family and non-family household members (HR = 2.86; 95% CI: 2.05, 3.98) compared to household heads were associated with a significantly increased hazard of NCD mortality. Although the difference was not statistically significant, compared to poor adults, those who were wealthy had a 15% (HR = 0.85; 95% CI: 0.65, 1.11) lower hazard of mortality from NCDs. On the other hand, literate adults (HR = 0.35; 95% CI: 0.13, 0.9) had a significantly decreased hazard of NCD attributed mortality compared to those adults who were unable to read and write. The effect of literacy was modified by age and its effect reduced by 18% for every 5-year increase of age among literate adults.ConclusionIn summary, the study indicates that double mortality burden from both NCDs and communicable diseases was evident in northern rural Ethiopia. Public health intervention measures that prioritise disadvantaged NCD patients such as those who are unable to read and write, the elders, the extended family and non-family household co-residents could significantly reduce NCD mortality among the adult population.引言 在发展中国家，非传染性疾病（non-communicable diseases, NCDs）所致的死亡与残疾负担正显著上升。然而，针对发展中国家情境下非传染性疾病归因死亡的社会决定因素所产生的影响，目前学界尚缺乏充分认知。本研究针对埃塞俄比亚提格雷东部地区，探讨了成人非传染性疾病归因死亡的疾病负担及其社会经济决定因素。 方法 本研究采用基于社区的动态队列研究设计，于2009年9月至2015年4月期间对45982名成人进行随访，记录其死亡事件。研究采用基于医师评审的口述尸检（verbal autopsy）方法，以确定死者最可能的死因。此外，通过多变量Cox比例风险回归模型，识别非传染性疾病死亡的社会决定因素。 结果 本研究累计随访193758.7人年，共记录1091例成人死亡事件。与传染性疾病相比，非传染性疾病所致成人死亡占比略高，分别为34.5%与33%。非传染性疾病归因死亡的发病密度率（incidence density rate, IDR）为每10万人年194.1例（IDR=194.1；95%置信区间：175.4~214.7）。在376例非传染性疾病死亡病例中，分别有157例（41.8%）、68例（18.1%）与34例（9%）归因于心血管疾病、癌症与肾衰竭。 多变量分析结果显示，年龄每增加5年（风险比（hazard ratio, HR）=1.35；95%置信区间：1.30~1.41），以及与户主相比，大家庭成员及非家庭同住成员的非传染性疾病死亡风险均显著升高（HR=2.86；95%置信区间：2.05~3.98）。尽管差异未达到统计学显著性，但与贫困成人相比，富裕成人的非传染性疾病死亡风险降低15%（HR=0.85；95%置信区间：0.65~1.11）。另一方面，与不识字的成人相比，识字成人的非传染性疾病归因死亡风险显著降低（HR=0.35；95%置信区间：0.13~0.9）。识字状况对死亡风险的影响受年龄调节：在识字成人中，年龄每增加5年，该保护效应降低18%。 结论 综上，本研究表明埃塞俄比亚北部农村地区同时面临传染性疾病与非传染性疾病的双重死亡负担。针对弱势非传染性疾病患者（如不识字人群、老年人、大家庭成员及非家庭同住者）制定优先级公共卫生干预措施，可显著降低成人人群的非传染性疾病死亡风险。