Veterans Administration, Tennessee Valley Healthcare System, Tennessee Valley Geriatric Research Education Clinical Center (GRECC), Nashville, TN 37212, USA.
Pharmacoepidemiol Drug Saf. 2009 Nov;18(11):1064-71. doi: 10.1002/pds.1821.
Studies of non-steroidal anti-inflammatory drugs (NSAIDs) and cardiovascular events using administrative data require identification of incident acute myocardial infarctions (AMIs) and information on whether confounders differ by NSAID status.
We identified patients with a first AMI hospitalization from Tennessee Medicaid files as those with primary ICD-9 discharge diagnosis 410.x and hospitalization stay of > 2 calendar days. Eligible persons were non-institutionalized, aged 50-84 years between 1999-2004, had continuous enrollment and no AMI, stroke, or non-cardiovascular serious medical illness in the prior year. Of 5524 patients with a potential first AMI, a systematic sample (n = 350) was selected for review. Using defined criteria, we classified events using chest pain history, EKG, and cardiac enzymes, and calculated the positive predictive value (PPV) for definite or probable AMI.
337 of 350 (96.3%) charts were abstracted and 307 (91.1%), 6 (1.8%), and 24 (7.1%) events were categorized as definite, probable, and no AMI, respectively. PPV for any definite or probable AMI was 92.8% (95% CI 89.6-95.2); for an AMI without an event in the past year 91.7% (95% CI 88.3-94.2), and for an incident AMI was 72.7% (95% CI 67.7-77.2). Age-adjusted prevalence of current smoking (46.4% vs. 39.1%, p = 0.35) and aspirin use (36.9% vs. 35.9%, p = 0.90) was similar among NSAID users and non-users
ICD-9 code 410.x had high predictive value for identifying AMI. Among those with AMI, smoking and aspirin use was similar in NSAID exposure groups, suggesting these factors will not confound the relationship between NSAIDs and cardiovascular outcomes.
利用行政数据研究非甾体抗炎药（NSAIDs）与心血管事件时，需要确定首发急性心肌梗死（AMI）病例，并了解混杂因素是否因 NSAID 使用状况而存在差异。
我们从田纳西州医疗补助档案中确定了首次 AMI 住院患者，这些患者的 ICD-9 主要出院诊断为 410.x，住院时间超过 2 个日历日。符合条件的患者为非住院、年龄在 50-84 岁之间、1999-2004 年期间连续参保且在过去一年中没有发生 AMI、中风或非心血管严重疾病。在 5524 例可能首次发生 AMI 的患者中，我们选择了一个系统样本（n = 350）进行复查。我们使用明确的标准，根据胸痛史、EKG 和心脏酶谱对事件进行分类，并计算明确或可能 AMI 的阳性预测值（PPV）。
在 350 份病历中，有 337 份（96.3%）被提取，307 份（91.1%）、6 份（1.8%）和 24 份（7.1%）分别被归类为明确、可能和无 AMI。任何明确或可能 AMI 的 PPV 为 92.8%（95%CI 89.6-95.2）；在过去一年中没有发生 AMI 的情况下，PPV 为 91.7%（95%CI 88.3-94.2），而在发生 AMI 的情况下，PPV 为 72.7%（95%CI 67.7-77.2）。年龄调整后，当前吸烟者（46.4%比 39.1%，p = 0.35）和阿司匹林使用者（36.9%比 35.9%，p = 0.90）在 NSAID 使用组和非 NSAID 使用组中的比例相似。
ICD-9 编码 410.x 对识别 AMI 具有较高的预测价值。在发生 AMI 的患者中，吸烟和阿司匹林的使用在 NSAID 暴露组中相似，这表明这些因素不会影响 NSAIDs 与心血管结局之间的关系。
