Level of Education Modifies Asthma Mortality in Norway and Sweden. The Nordic EpiLung Study

Figures & data

Table 1 Baseline Characteristics in Sweden and Norway, Among Participants with and without Asthma, and Among All

Characteristics		Sweden			Norway
		Without Asthma	With Asthma	All N=18356	Without Asthma	With Asthma	All N=37973
		N=16825	N=1531		N=35108	N=2865
Age	Mean (SD)	50.0 (11.3)	48.7 (11.2)	49.9 (11.3)	50.8 (10.5)	51.5 (10.9)	50.9 (10.6)
Sex	Women	52.5%	59.4%	53.1%	53.6%	58.3%	54.0%
Smoking	Non-smokers	58.6%	52.1%	58.1%	41.2%	31.2%	40.5%
	Ex-smokers	24.9%	28.9%	25.2%	31.6%	36.5%	31.9%
	Current smokers	16.4%	19.0%	16.7%	27.2%	32.3%	27.6%
Number of	<5 cig/day	4.0%	4.7%	4.1%	1.2%	0.9%	1.2%
cigarettes/day	5–14 cig/day	7.2%	8.5%	7.3%	13.2%	15.7%	13.3%
Among current	>14 cig/day	4.2%	4.0%	4.2%	6.3%	10.0%	6.6%
smokers	Missing	1.0%	1.8%	1.1%	6.5%	5.7%	6.5%
Educational level	Primary	15.7%	15.7%	15.7%	20.6%	26.1%	21.0%
	Upper secondary	52.4%	57.0%	52.8%	51.1%	51.5%	51.1%
	Tertiary	31.9%	27.3%	31.5%	28.3%	22.4%	27.9%

Notes: Characteristics are presented as column percent (%) except for age which is presented as mean (standard deviation).

Abbreviation: N, Number of individuals.

Table 2 10-Year Mortality and Attributable Mortality Risk Due to Asthma, Stratified by Educational Level and Among All

Educational Level	Sweden				Norway				All
	Without Asthma N (per 1000 PY)	With Asthma N (per 1000 PY)	All N (Per 1000 PY)	Proportion (%) of Mortality Risk Attributable to Asthma	Without Asthma N (per 1000 PY)	With Asthma N (per 1000 PY)	All N (Per 1000 PY)	Proportion (%) of Mortality Risk Attributable to Asthma	Proportion (%) of Mortality Risk Attributable to Asthma
Primary	272 (10.9)	33 (14.7)	305 (11.2)	2.8%	420 (6.0)	91 (12.9)	511 (6.6)	10.0%	7.6%
Upper secondary	397 (4.6)	53 (6.3)	450 (4.8)	3.3%	668 (3.8)	97 (6.8)	765 (4.0)	5.7%	4.8%
Tertiary	148 (2.8)	13 (3.2)	161 (2.8)	0.9%	240 (2.4)	24 (3.8)	264 (2.5)	3.2%	2.4%
Total	817 (5.0)	99 (6.7)	916 (5.1)	2.8%	1328 (3.8)	212 (7.6)	1540 (4.1)	7.0%	5.5%

Notes: The proportion of mortality risk attributable to asthma was calculated using Levin’s formula (please see methods section for details).

Abbreviation: N=Number of individuals, PY=Person-years.

Figure 1 Mortality incidence curves among adults with asthma (red) compared to without asthma (black) and stratified by education.

Figure 2 Asthma as a risk factor for 10-year mortality, among all participants and stratified by educational levels. Results are expressed as Hazard ratios with 95% Confidence intervals (CI) from crude Cox proportional hazard models, and from models adjusted for age, sex and smoking.

Figure 3 Asthma as a risk factor for 10-year mortality, among men, women, non-smokers, and ever-smokers, in all and stratified by educational levels. Results are expressed as Hazard ratios with 95% Confidence intervals (CI) from crude Cox proportional hazard models, and from models adjusted for age, sex and smoking.