Table 3

Number and distribution of confirmed AMI cases by diagnostic code or free text

Database/codeCode descriptionNumber of records reviewedNumber of cases confirmedPercentage of cases identified by such code or free text in random samplePPV, best-case scenario (95% CI)PPV, worst case scenario (95% CI)
IPCI
 ICPC K75-AMI2009310075.0 (67.4 to 82.6)46.5 (37.7 to 55.3)
 Free textSpecific key words*2002610019.7 (12.9 to 26.5)13.0 (7.3 to 18.7)
HSD
 ICD9-CM
  410 or 410.0AMI of anterolateral wall1266.085.7 (59.8 to 100)50.0 (13.0 to 87.0)
  410.1 or 410.10AMI of other anterior wall442.0100100
  410.20AMI of inferolateral wall110.5100100
  410.3AMI of inferoposterior wall110.5100100
  410.7Subendocardial infarction321.510066.7 (1.3 to 100)
  410.9 or 410.90AMI, unspecified site1579478.596.9 (93.5 to 100)59.9 (50.1 to 69.6)
  410.9+Free textAMI, unspecified site844.010050.0 (1.0 to 99.0)
  411.81+Free textAcute coronary occlusion without MI100.500
  Free textSpecific key words*1336.560 (17.1 to 100)23.1 (0 to 60.0)
Aarhus
 ICD-10
  I21.0Acute transmural MI of anterior wall202013.510074.1 (54.9 to 93.3)
  I21.1Acute transmural MI of inferior wall171711.510073.9 (53.0 to 94.8)
  I21.2Acute transmural MI of other sites221.410066.7 (1.3 to 100)
  I21.3Acute transmural MI of unspecified site262617.610074.3 (57.5 to 91.1)
  I21.4Acute subendocardial MI565637.810073.7 (62.2 to 85.2)
  I21.9AMI, unspecified272718.210075.0 (58.7 to 91.3)
  • *See online supplementary appendix 2 for key words used.

  • Best-case scenario: non-assessable and non-retrievable cases are not included in the numerator or denominator when the PPV is calculated.

  • Worst-case scenario: both non-assessable and non-retrievable cases are included in the denominator when the PPV is calculated. For Aarhus, the number of cases that would have been retrieved per code was estimated based on the % distribution of codes in the retrieved cases within the random sample.

  • AMI, acute myocardial infarction; HSD, Health Search/CSD Patient DB; ICD9-CM, International Classification of Diseases 9th revision-clinical modification; ICPC, International Classification of Primary Care; IPCI, Integrated Primary Care Information.