Temporal variation in case fatality of acute myocardial infarction in Finland

Figures & data

Table

AMI	acute myocardial infarction
CDS	Cause of Death Statistics
CHD	Coronary heart disease
DALY	Disability-adjusted life year
HDR	Hospital Discharge Registry
ICD	International Classification of Diseases
MSE	mean squared error
WHO	World Health Organization

Table

NT	incl. age and sex only
LT	incl. age, sex, and linear trend
FS	incl. age, sex, and seasonal Fourier terms
W0	incl. age, sex, and weather covariates
WS	incl. age, sex, seasonal Fourier terms, and weather covariates

Figure 1.  The study area includes the seven largest cities of Finland.

Figure 2.  Monthly variation of first acute myocardial infarction (AMI) incidence and first AMI case fatality rates by age-group and sex for the years 1983, 1988, and 1993.

Figure 3.  Weekly variation of first acute myocardial infarction (AMI) incidence and first AMI case fatality rates by age-group and sex for the years 1983, 1988, and 1993.

Table I.  First acute myocardial infarction (AMI) case fatality rates by sex, year, and age-group in Finland.

	25–54 years old		55–64 years old		65–74 years old
Year	Death/cases	Rate	Death/cases	Rate	Deaths/cases	Rate
Men
1983	165/521	32% (28%; 36%)	280/608	46% (42%; 50%)	378/675	43% (52%; 60%)
1988	140/462	30% (26%; 35%)	246/575	43% (39%; 47%)	318/574	55% (51%; 60%)
1993	136/403	34% (29%; 38%)	183/470	39% (35%; 43%)	335/598	56% (52%; 60%)
Women
1983	23/95	24% (16%; 33%)	75/224	34% (27%; 40%)	269/593	45% (41%; 49%)
1988	17/87	20% (11%; 28%)	78/207	38% (31%; 44%)	267/545	49% (45%; 53%)
1993	13/56	23% (12%; 34%)	52/175	30% (23%; 37%)	221/460	48% (43%; 53%)

Table II.  Coefficients and the mean squared errors (MSE) obtained from a 1-out cross-validation for the five different models of increasing complexity.

Model	No trend (NT)		Linear trend (LT)		Seasonal Fourier terms (FS)		Weather (W0)		W0 + FS (WF)
	Coefficient	P-value	Coefficient	P-value	Coefficient	P-value	Coefficient	P-value	Coefficient	P-value
Sex	−1.357	0.002	−1.358	0.002	−1.301	0.003	−1.348	0.002	−1.290	0.003
Age	0.043	<0.000	0.044	<0.000	0.044	<0.000	0.044	<0.000	0.044	<0.000
Sex×age	0.015	0.027	0.015	0.027	0.014	0.038	0.014	0.029	0.014	0.041
Temp ^a	–	–	–	–	–	–	−0.008	0.066	−0.001	0.930
Temp2 ^b	–	–	–	–	–	–	0.001	0.06	0.001	0.205
Time, t ^c	–	–	−0.002	0.710	–	–	–	–	–	–
SinWeek ^d	–	–	–	–	0.065	0.050	–	–	0.066	0.048
CosWeek ^d	–	–	–	–	0.141	<0.000	–	–	0.142	<0.000
MSE	0.2360		0.2360		0.2354		0.2362		0.2357

^a Temperature.

^b Temperature squared.

^c Change over time (linear trend).

^d Fourier terms, functions of the day of the week.

Table III.  Monthly case fatality rates of acute myocardial infarction in Finland 1983, 1988, and 1993 by sex and age.

	Men						Women
Age	25–54 years		55–64 years		65–74 years		25–54 years		55–64 years		65–74 years
Month	Deaths/cases	Rate	Deaths/cases	Rate	Deaths/cases	Rate	Deaths/cases	Rate	Deaths/cases	Rate	Deaths/cases	Rate
Jan	32/117	27%	54/139	39%	73/150	49%	7/23	30%	19/51	37%	68/147	46%
Feb	33/95	35%	63/136	46%	80/147	54%	2/19	11%	18/47	38%	65/127	51%
Mar	40/119	34%	73/150	49%	90/169	53%	3/22	14%	15/48	31%	58/147	39%
Apr	41/123	33%	66/143	46%	92/149	62%	7/25	28%	19/57	33%	61/145	42%
May	35/121	29%	41/124	33%	91/150	61%	3/19	16%	17/48	35%	58/120	48%
Jun	41/133	31%	65/156	42%	96/168	57%	8/24	33%	17/51	33%	59/112	53%
Jul	34/123	28%	67/137	49%	88/147	60%	1/14	7%	12/36	33%	74/136	54%
Aug	44/108	41%	69/157	44%	78/150	52%	2/19	11%	13/48	27%	57/137	42%
Sep	30/106	28%	54/132	41%	71/151	47%	5/22	23%	15/55	27%	56/128	44%
Oct	42/122	34%	52/124	42%	87/174	50%	3/18	17%	17/57	30%	67/131	51%
Nov	32/127	25%	48/127	38%	89/156	57%	5/21	24%	22/63	35%	59/141	42%
Dec	37/92	40%	57/128	45%	96/136	71%	7/12	58%	21/45	47%	75/127	59%