Department of Neurology, Clinical Research Center, Ilsan Paik Hospital, Inje University, Goyang, Korea.
Stroke. 2010 Mar;41(3):471-7. doi: 10.1161/STROKEAHA.109.571083. Epub 2010 Feb 4.
Disability-adjusted life year (DALY) metric reflects years of healthy life lost because of living with disability and years of life lost because of premature mortality. Widely used in epidemiological analyses, DALY has not been applied to acute stroke trials.
From previous studies, we derived, for each modified Rankin Scale level, disability weights, disability-linked mortality hazard ratios, and age-specific life expectancies. We then analyzed patient level data from the 2 publicly available National Institute of Neurological Disorders and Stroke (NINDS) recombinant tissue plasminogen activator trials. For each subject, we abstracted age, treatment assignment, and 3-month modified Rankin Scale outcome and calculated the DALYs lost resulting from the qualifying stroke.
The disability-linked hazard ratios for premature annual mortality for a modified Rankin Scale score of 0 to 5 were 1.53, 1.52, 2.17, 3.18, 4.55, and 6.55, respectively. In the NINDS recombinant tissue plasminogen activator trials, DALYs (mean+/-SE) lost as a result of the qualifying stroke were substantially less with recombinant tissue plasminogen activator than with placebo (4.64+/-0.17 versus 5.91+/-0.21; P<0.0001), a finding that remained robust after adjustment for baseline prognostic factors. When DALYs gained were apportioned to the 29% of patients experiencing any benefit from lytic therapy, each patient gained an average of 4.4 DALYs. DALY analysis showed greater power than dichotomized modified Rankin Scale analysis in discriminating treatment effects overall and in patients >or=70 years of age.
For patients who benefit from treatment, <3-hour thrombolytic therapy adds the equivalent of 4.4 years of healthy life, free of disability. The DALY metric provides a continuous scale that increases statistical power, is intuitively understandable, and is applicable to a wide range of conditions and treatments.
失能调整生命年（DALY）指标反映了因残疾而丧失的健康生命年数和因过早死亡而丧失的生命年数。该指标广泛应用于流行病学分析，但尚未应用于急性脑卒中试验。
我们从以往的研究中得出了每个改良 Rankin 量表（mRS）水平的失能权重、失能相关死亡风险比和特定年龄的预期寿命。然后，我们分析了 2 项公开的美国国立神经病学与卒中研究院（NINDS）重组组织型纤溶酶原激活剂试验的患者水平数据。对于每个受试者，我们提取年龄、治疗分配和 3 个月的 mRS 结局，并计算符合溶栓标准的脑卒中所导致的 DALY 损失。
mRS 评分为 0 至 5 分的患者，每年因过早死亡而导致的失能相关死亡风险比分别为 1.53、1.52、2.17、3.18、4.55 和 6.55。在 NINDS 重组组织型纤溶酶原激活剂试验中，与安慰剂相比，重组组织型纤溶酶原激活剂治疗导致的 DALY（平均值+/-标准误）损失显著减少（4.64+/-0.17 对 5.91+/-0.21；P<0.0001），这一结果在调整基线预后因素后仍然稳健。当将 DALY 增益分配给 29%的患者时，他们从溶栓治疗中获益，每位患者平均获得了 4.4 DALY。DALY 分析在总体和≥70 岁的患者中，在判别治疗效果方面比二分 mRS 分析具有更大的效力。
对于从治疗中获益的患者，<3 小时的溶栓治疗可增加相当于 4.4 年的无残疾健康生命。DALY 指标提供了一个连续的尺度，增加了统计效力，直观易懂，适用于广泛的疾病和治疗。
