Validating Acute Myocardial Infarction Diagnoses in National Health Registers for Use as Endpoint in Research: The Tromsø Study

Figures & data

Figure 1 Study population. Participants in the Tromsø Study 1–6.

Figure 2 Estimated positive predictive value (PPV) and sensitivity for myocardial infarction diagnoses in the national registers compared to the gold standard (the Tromsø Study Cardiovascular Disease Register). Error bars show 95% confidence intervals.

Table 1 Distribution of True and False Positives and Negatives in the National Registers Compared to the Gold Standard (The Tromsø Study Cardiovascular Disease Register)

	Gold Standard: The Tromsø Study Cardiovascular Disease Register
	MI^a	No MI	Total
The Norwegian Myocardial Infarction Register
MI	135	4	139
No MI	18	23,508	23,526
Total	153	23,512	23,665
The Norwegian Patient Register
MI	131	5	136
No MI	22	23,507	23,529
Total	153	23,512	23,665
Combination of the Norwegian Myocardial Infarction Register and the Norwegian Patient Register
MI	140	5	145
No MI	13	23,507	23,520
Total	153	23,512	23,665

Abbreviation: ^aMI, myocardial infarction.

Table 2 Results from Post-Hoc Review of Medical Records for All False Negative and False Positive Cases Identified in the Validation Analyses

	False Negatives		False Positives
	NorMI^a	NPR^b	NorMI^a		NPR^b
Incorrect Registration in Gold Standard^c
Did not fulfill myocardial infarction (MI) criteria	3	3
In-hospital cardiac arrest, no MI (ICD-10 code I46)	1	1
Type 2-infarction			4		4
Total	4	4	4		4
Correct Registration in Gold Standard^c
No MI diagnosis in hospital records, but fulfilled MI criteria	6	6
MI diagnosis in hospital records and fulfilled MI criteria	7	11
Patient treated for MI abroad	1	1
Did not fulfill myocardial infarction (MI) criteria					1
Total	14	18
Total	18	22	4		5

Notes: ^aThe Norwegian Myocardial Infarction Register (NorMI). ^bThe Norwegian Patient Register (NPR). ^cThe Tromsø Study Cardiovascular Disease Register.