Validity of Myocardial Infarction Diagnoses in Administrative Databases: A Systematic Review

Background
Though administrative databases are increasingly being used for research related to myocardial infarction (MI), the validity of MI diagnoses in these databases has never been synthesized on a large scale.
Objective
To conduct the first systematic review of studies reporting on the validity of diagnostic codes for identifying MI in administrative data.
Methods
MEDLINE and EMBASE were searched (inception to November 2010) for studies: (a) Using administrative data to identify MI; or (b) Evaluating the validity of MI codes in administrative data; and (c) Reporting validation statistics (sensitivity, specificity, positive predictive value (PPV), negative predictive value, or Kappa scores) for MI, or data sufficient for their calculation. Additonal articles were located by handsearch (up to February 2011) of original papers. Data were extracted by two independent reviewers; article quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies tool.
Results
Thirty studies published from 1984–2010 were included; most assessed codes from the International Classification of Diseases (ICD)-9th revision. Sensitivity and specificity of hospitalization data for identifying MI in most [≥50%] studies was ≥86%, and PPV in most studies was ≥93%. The PPV was higher in the more-recent studies, and lower when criteria that do not incorporate cardiac troponin levels (such as the MONICA) were employed as the gold standard. MI as a cause-of-death on death certificates also demonstrated lower accuracy, with maximum PPV of 60% (for definite MI).
Conclusions
Hospitalization data has higher validity and hence can be used to identify MI, but the accuracy of MI as a cause-of-death on death certificates is suboptimal, and more studies are needed on the validity of ICD-10 codes. When using administrative data for research purposes, authors should recognize these factors and avoid using vital statistics data if hospitalization data is not available to confirm deaths from MI.

背景
尽管管理型医疗数据库（administrative databases）正日益被应用于与心肌梗死（myocardial infarction, MI）相关的研究，但目前尚无大规模综述对这类数据库中心梗诊断的有效性进行综合分析。
研究目的
本研究旨在开展首项系统性综述，对评估管理型医疗数据库中用于识别心肌梗死（MI）的诊断编码有效性的相关研究进行综合分析。
研究方法
检索MEDLINE与EMBASE数据库（建库至2010年11月），纳入符合以下条件的研究：(a) 利用管理型医疗数据库识别MI；或(b) 评估管理型医疗数据库中MI诊断编码的有效性；且(c) 报告了MI的验证统计指标（灵敏度、特异度、阳性预测值（positive predictive value, PPV）、阴性预测值或Kappa值），或提供了可用于计算上述指标的原始数据。此外，通过手工检索原始文献（检索截止至2011年2月）补充获取相关文献。研究数据由2名独立评审员独立提取；采用诊断准确性研究质量评价工具（Quality Assessment of Diagnostic Accuracy Studies tool）对纳入文献的质量进行评估。
研究结果
最终纳入1984年至2010年发表的30项研究，其中大多数评估了国际疾病分类第9版（International Classification of Diseases 9th revision, ICD-9）编码的有效性。在≥50%的纳入研究中，用于识别MI的住院数据其灵敏度与特异度均≥86%，且多数研究中的阳性预测值（PPV）≥93%。近期开展的研究中PPV更高，而当采用未纳入心肌肌钙蛋白水平的判定标准（如多国心血管病趋势和决定因素监测方案（MONICA））作为金标准时，PPV则相对更低。死亡证明书中标注为MI死因的诊断准确性同样欠佳，其阳性预测值最高仅为60%（针对确诊MI病例）。
研究结论
住院数据具有更高的诊断有效性，因此可用于识别MI，但死亡证明书中将MI列为死因的诊断准确性并不理想，且目前仍需开展更多针对国际疾病分类第10版（International Classification of Diseases 10th revision, ICD-10）编码有效性的研究。在利用管理型医疗数据库开展研究时，研究者应充分考虑上述因素，若无法获取住院数据以验证MI致死病例，则应避免使用生命统计数据。