Andersen Klaus Kaae, Olsen Tom Skyhøj
Statistics and Pharmacoepidemiology Danish Cancer Society Research Center, Copenhagen, Denmark.
Department of Neurology, Bispebjerg University Hospital, Copenhagen, Denmark.
J Stroke Cerebrovasc Dis. 2019 Jun;28(6):1529-1536. doi: 10.1016/j.jstrokecerebrovasdis.2019.03.013. Epub 2019 Mar 28.
It is unclear whether social inequality exists for mortality after stroke. Results of studies on the relation between socioeconomic position (SEP) and mortality after stroke have been inconsistent and inconclusive.
We studied the association between SEP expressed by income and the risk of death after stroke by merging data on incident stroke from Danish registries with nationwide coverage. We identified all incident cases of stroke hospitalized in Denmark 2003-2012 (n = 60503). Patients were followed up to 9 years after stroke (median 2.6 years). Adjusting for age and sex we studied all-cause death and cause-specific death by stroke, cardiac disease, cancer, and other diseases certified by death records and stratified by income.
Of the patients 20,953 (34.6%) had died within follow-up: Death by stroke 8018 (13.2%); cardiac disease 4250 (7.0%); cancer 3060 (5.0%); other diseases 5625 (9.2%). Long-term mortality rates were inversely related to income for all causes of death. The difference in mortality between the lowest and the highest income group at 5 years after stroke was 15.5% (relative) and 5.7% (absolute). Differences in short-term mortality (1-month to 1-year) between income groups were small and clinically insignificant.
Social inequality in mortality after stroke expressed by income was pronounced for long-term mortality while not for short-term mortality. It seems that social inequality is expressed in a greater risk among stroke patients with low income for the advent of new diseases subsequently leading to death rather than in their ability to survive the incident stroke.
目前尚不清楚中风后死亡率是否存在社会不平等现象。关于社会经济地位（SEP）与中风后死亡率之间关系的研究结果一直不一致且尚无定论。
我们通过将丹麦登记处全国范围覆盖的中风发病数据合并，研究了以收入表示的SEP与中风后死亡风险之间的关联。我们确定了2003年至2012年在丹麦住院的所有中风发病病例（n = 60503）。患者在中风后随访9年（中位数为2.6年）。在调整年龄和性别后，我们研究了全因死亡以及由中风、心脏病、癌症和死亡记录证明的其他疾病导致的死因特异性死亡，并按收入分层。
在患者中，20953人（34.6%）在随访期间死亡：中风死亡8018人（13.2%）；心脏病死亡4250人（7.0%）；癌症死亡3060人（5.0%）；其他疾病死亡5625人（9.2%）。所有死因的长期死亡率与收入呈负相关。中风后5年时，最低收入组和最高收入组之间的死亡率差异为15.5%（相对）和5.7%（绝对）。收入组之间的短期死亡率（1个月至1年）差异较小且临床意义不大。
以收入表示的中风后死亡率的社会不平等在长期死亡率方面较为明显，而在短期死亡率方面则不明显。似乎社会不平等表现为低收入中风患者出现随后导致死亡的新疾病的风险更高，而非他们在中风发病后存活的能力方面。
