The validity of hospital discharge register data on non-ST-elevation and ST-elevation myocardial infarction in Finland

Figures & data

Figure 1. Flowchart of patient selection in the first stage of the study. FINAMI: Finnish Myocardial Infarction Register; MI: myocardial infarction; ECG: electrocardiogram; NCMI: not classifiable myocardial infarction; STEMI: ST-elevation myocardial infarction; NSTEMI: non-ST-elevation myocardial infarction; HDR: hospital discharge register.

Figure 2. Flowchart of patient selection in the second stage of the study. HDR: hospital discharge register; ECG: electrocardiogram; MI: myocardial infarction; NCMI: not classifiable myocardial infarction; STEMI: ST-elevation myocardial infarction; NSTEMI: non-ST-elevation myocardial infarction.

Table 1. Characteristics of FINAMI patients randomly sampled to the study from the HDR.

	Study area			Total
	Turku	Oulu	Joensuu
N(men/women)	34 (17/17)	53 (26/27)	39 (19/20)	126 (62/64)
Age	69.8 (11.6)	69.7 (13.4)	69.4 (14.9)	69.6 (13.3)
N HDR STEMI	12	19	15	46
N HDR NSTEMI	12	17	15	44
N HDR NCMI	10	17	9	36

HDR: Finnish Hospital Discharge Registry; STEMI: ST-elevation myocardial infarction; NSTEMI: non-ST-elevation myocardial infarction; NCMI: not classifiable myocardial infarction.

Table 2. Characteristics of patients randomly sampled to the study from the HDR.

	Study Area			Total
	Turku	Oulu	Joensuu
N(men/women)	84 (42/42)	73 (36/37)	81 (41/40)	238 (119/119)
Age	75.5 (14.2)	70.9 (14.7)	74.2 (12.2)	73.6 (13.8)
N HDR STEMI	27	25	28	80
N HDR NSTEMI	29	29	27	85
N HDR NCMI	28	19	26	73

HDR: Finnish Hospital Discharge Registry; STEMI: ST-elevation myocardial infarction; NSTEMI: non-ST-elevation myocardial infarction; NCMI: not classifiable myocardial infarction.

Table 3. Cohen’s kappa and confidence intervals from years 2012 to 2014 by study area for men, women, and total.

		Joensuu		Oulu		Turku		Total
		κ	CI	κ	CI	κ	CI	κ	CI
Men	Analyst versus senior	0.86	0.64–1.09	0.89	0.64–1.14	0.57	0.33–0.80	0.77	0.63–0.90
	Analyst versus HDR	0.37	0.18–0.57	0.33	0.11–0.55	0.25	0.06–0.44	0.32	0.20–0.43
Women	Analyst versus senior	0.66	0.43–0.89	0.81	0.56–1.06	0.68	0.40–0.95	0.73	0.58–0.87
	Analyst versus HDR	0.11	−0.06 to 0.27	0.24	0.02–0.46	0.31	0.13–0.49	0.22	0.11–0.30
Total	Analyst versus senior	0.77	0.61–0.93	0.85	0.67–1.02	0.62	0.44–0.80	0.75	0.65–0.85
	Analyst versus HDR	0.24	0.11–0.37	0.28	0.13–0.44	0.28	0.15–0.41	0.27	0.19–0.35

κ: Cohen’s kappa; CI: confidence interval; HDR: Finnish Hospital Discharge Registry.

Table 4. Sensitivity and specificity and confidence intervals of STEMI diagnoses in HDR compared to classification of the cardiology resident.

	Turku		Oulu		Joensuu		Total
		CI		CI		CI		CI
FINAMI: STEMI
SENS	0.64	(0.35–0.87)	0.50	(0.27–0.73)	0.50	(0.27–0.73)	0.54	(0.40–0.67)
SPEC	0.85	(0.62–0.97)	0.73	(0.54–0.87)	0.74	(0.49–0.91)	0.76	(0.65–0.86)
Later HDR STEMI
SENS	0.62	(0.41–0.81)	0.79	(0.54–0.94)	0.67	(0.38–0.88)	0.69	(0.55–0.80)
SPEC	0.80	(0.68–0.89)	0.81	(0.69–0.91)	0.73	(0.60–0.83)	0.78	(0.71–0.84)

FINAMI: Finnish Myocardial Infarction register; STEMI: ST-elevation myocardial infarction; CI: confidence interval; HDR: Finnish Hospital Discharge Registry; SENS: Sensitivity, SPEC: Specificity.

Table 5. Sensitivity and specificity and confidence intervals of NSTEMI diagnoses in HDR compared to classification of the cardiology resident.

	Turku		Oulu		Joensuu		Total
		CI		CI		CI		CI
FINAMI NSTEMI
SENS	0.45	(0.23–0.68)	0.39	(0.23–0.58)	0.58	(0.33–0.80)	0.46	(0.34–0.58)
SPEC	0.79	(0.49–0.95)	0.80	(0.56–0.94)	0.80	(0.56–0.94)	0.80	(0.66–0.89)
Later HDR NSTEMI
SENS	0.44	(0.30–0.59)	0.49	(0.34–0.64)	0.43	(0.30–0.58)	0.45	(0.37–0.54)
SPEC	0.81	(0.64–0.93)	0.75	(0.55–0.89)	0.86	(0.67–0.96)	0.81	(0.71–0.88)

FINAMI: Finnish Myocardial Infarction register; NSTEMI: non-ST-elevation myocardial infarction; CI: confidence interval; HDR: Finnish Hospital Discharge Registry; SENS: sensitivity; SPEC: specificity.