Table 1.

Descriptive statistics for 22,882 female nurses from the Danish Nurse Cohort at year of cohort entry in 1993 or 1999, by outcome.

Variables	Total ($n=\mathrm{22,882}$)	MI ($n=\mathrm{22,241}$)	Overall incident MI ($n=641$)	Fatal incident MI ($n=121$)
Age {y [mean (SD)]}	52.8 (7.7)	52.6 (7.6)	59.2 (9.2)	65.0 (10.3)
Body mass index {$\mathrm{kg}/{\mathrm{m}}^2$ [mean (SD)]}	23.7 (3.5)	23.7 (3.5)	24.3 (3.8)	24.1 (3.4)
Body mass index {$\mathrm{kg}/{\mathrm{m}}^2$ [$n$ (%)]}
Underweight ($<18.5$)	553 (2.4)	535 (2.4)	18 (2.8)	4 (3.3)
Normal weight (18.5–25)	15,820 (69.1)	15,427 (69.4)	393 (61.3)	71 (58.7)
Overweight (25–30)	5,214 (22.8)	5,033 (22.6)	181 (28.2)	37 (30.6)
Obese ($\ge 30$)	1,295 (5.7)	1,246 (5.6)	49 (7.6)	9 (7.4)
Smoking status [$n$ (%)]
Never	8,224 (35.9)	8,054 (36.2)	170 (26.5)	28 (23.1)
Previous	6,877 (30.1)	6,713 (30.2)	164 (25.6)	27 (22.3)
Current	7,781 (34.0)	7,474 (33.6)	307 (47.9)	66 (54.5)
Pack-years [$n$ (%)]
Never smoked	8,224 (35.9)	8,054 (36.2)	170 (26.5)	28 (23.1)
$\le 10$	6,458 (28.2)	6,312 (28.4)	146 (22.8)	24 (19.8)
11–20	3,723 (16.3)	3,596 (16.2)	127 (19.8)	22 (18.2)
$>20$	4,477 (19.6)	4,279 (19.2)	198 (30.9)	47 (38.8)
Alcohol consumption {drinks/week [$n$ (%)]}
None (0)	3,426 (15.0)	3,275 (14.7)	151 (23.6)	30 (24.8)
Moderate (1–15)	14,210 (62.1)	13,852 (62.3)	358 (55.9)	69 (57.0)
Heavy ($>15$)	5,246 (22.9)	5,114 (23.0)	132 (20.6)	22 (18.2)
Physical activity [$n$ (%)]
Low	1,454 (6.4)	1,390 (6.2)	64 (10.0)	26 (21.5)
Medium	15,273 (66.7)	14,834 (66.7)	439 (68.5)	78 (64.5)
High	6,155 (26.9)	6,017 (27.1)	138 (21.5)	17 (14.0)
Fruit consumption [$n$ (%)]
Rarely	828 (3.6)	805 (3.6)	23 (3.6)	6 (5.0)
Few times per week	6,516 (28.5)	6,324 (28.4)	192 (30.0)	34 (28.1)
Daily or several times per day	15,538 (67.9)	15,112 (67.9)	426 (66.5)	81 (66.9)
Avoids fatty meat [$n$ (%)]
No	2,123 (9.3)	2,046 (9.2)	77 (12.0)	12 (9.9)
Yes	20,759 (90.7)	20,195 (90.8)	564 (88.0)	109 (90.1)
Hypertension [$n$ (%)]a
No	20,054 (87.6)	19,592 (88.1)	462 (72.1)	77 (63.6)
Yes	2,828 (12.4)	2,649 (11.9)	179 (27.9)	44 (36.4)
Diabetes [$n$ (%)]a
No	22,628 (98.9)	22,008 (99.0)	620 (96.7)	110 (90.9)
Yes	254 (1.1)	233 (1.0)	21 (3.3)	11 (9.1)
Hormone therapy use [$n$ (%)]
Never	16,677 (72.9)	16,267 (73.1)	410 (64.0)	82 (67.8)
Past	2,236 (9.8)	2,128 (9.6)	108 (16.8)	19 (15.7)
Current	3,969 (17.3)	3,846 (17.3)	123 (19.2)	20 (16.5)
Oral contraceptive use [$n$ (%)]
Never	9,140 (39.9)	8,744 (39.3)	396 (61.8)	98 (81.0)
Ever	13,742 (60.1)	13,497 (60.7)	245 (38.2)	23 (19.0)
Menopausal status
Premenopausal	11,504 (50.3)	11,364 (51.1)	140 (21.8)	15 (12.4)
Postmenopausal	11,378 (49.7)	10,877 (48.9)	501 (78.2)	106 (87.6)
Employment status [$n$ (%)]
Actively working	18,305 (80.0)	17,962 (80.8)	343 (53.5)	38 (31.4)
Homemaker	407 (1.8)	396 (1.8)	11 (1.7)	2 (1.7)
Retired	3,808 (16.6)	3,527 (15.9)	281 (43.8)	80 (66.1)
Unemployed/rehabilitation	149 (0.7)	146 (0.7)	3 (0.5)	1 (0.8)
Other	213 (0.9)	210 (0.9)	3 (0.5)	0 (0.0)
Marital status [$n$ (%)]
Married	16,262 (71.1)	15,852 (71.3)	410 (64.0)	56 (46.3)
Separated	388 (1.7)	379 (1.7)	9 (1.4)	0 (0.0)
Divorced	2,593 (11.3)	2,531 (11.4)	62 (9.7)	11 (9.1)
Single	2,210 (9.7)	2,132 (9.6)	78 (12.2)	30 (24.8)
Widowed	1,429 (6.2)	1,347 (6.1)	82 (12.8)	24 (19.8)
Urbanization level [$n$ (%)]
Rural	9,428 (41.2)	9,139 (41.1)	289 (45.1)	57 (47.1)
Provincial	9,973 (43.6)	9,728 (43.7)	245 (38.2)	47 (38.8)
Urban	3,481 (15.2)	3,374 (15.2)	107 (16.7)	17 (14.0)
Average municipality income {DKK [mean (SD)]}b	164,487.4 (24,855.9)	164,546.4 (24,914.5)	162,442.1 (22,652.3)	160,236.4 (22,208.6)
Air pollution levels at cohort entry (1-y mean)c
${\mathrm{PM}}_{2.5}$ levels {$\mathrm{\mu }\mathrm{g}/{\mathrm{m}}^3$ [mean (SD)]}	19.6 (3.6)	19.6 (3.6)	21.0 (3.4)	21.5 (3.3)
${\mathrm{PM}}_{10}$ levels {$\mathrm{\mu }\mathrm{g}/{\mathrm{m}}^3$ [mean (SD)]}	23.5 (3.9)	23.4 (3.9)	25.2 (3.6)	25.8 (3.6)
${\mathrm{NO}}_2$ levels {$\mathrm{\mu }\mathrm{g}/{\mathrm{m}}^3$ [mean (SD)]}	12.6 (8.1)	12.6 (8.0)	13.6 (9.6)	14.2 (10.7)
${\mathrm{NO}}_{\mathrm{x}}$ levels {$\mathrm{\mu }\mathrm{g}/{\mathrm{m}}^3$ [mean (SD)]}	19.1 (24.4)	19.1 (24.2)	22.0 (29.7)	24.4 (34.9)
Road traffic noise levels at cohort entry (1-y mean)d,e
${\mathrm{L}}_{\text{den}}$ {dB [mean (SD)]}	52.8 (8.2)	52.8 (8.1)	52.8 (8.6)	53.1 (8.2)
${\mathrm{L}}_{\text{den}}$ {dB [$n$ (%)]}	7,509 (33.1)	7,292 (33.0)	217 (34.2)	40 (34.5)
Low ($<50.4$)	7,582 (33.4)	7,379 (33.4)	203 (32.0)	36 (31.0)
Medium (50.4–56.2)	7,624 (33.6)	7,410 (33.6)	214 (33.8)	40 (34.5)
High ($\ge 56.2$)	7,509 (33.1)	7,292 (33.0)	217 (34.2)	40 (34.5)

Note: DKK, Danish Crowns; ${\mathrm{L}}_{\text{den}}$, joint expression of day (${\mathrm{L}}_{\mathrm{d}}$; 0700–1900 hours), evening (${\mathrm{L}}_{\mathrm{e}}$; 1900–2200 hours), and night (${\mathrm{L}}_{\mathrm{n}}$; 2200–0700 hours) road traffic noise levels, with 5 and $10\text{dB}$ penalties added to ${\mathrm{L}}_{\mathrm{e}}$ and ${\mathrm{L}}_{\mathrm{n}}$, respectively; MI, myocardial infarction; ${\mathrm{NO}}_2$, nitrogen dioxide; ${\mathrm{NO}}_{\mathrm{x}}$, nitrogen oxides; PM, particulate matter; ${\mathrm{PM}}_{2.5}$, PM with an aerodynamic diameter of $<2.5\mathrm{\mu }\mathrm{g}/{\mathrm{m}}^3$; ${\mathrm{PM}}_{10}$, PM with an aerodynamic diameter of $<10\mathrm{\mu }\mathrm{g}/{\mathrm{m}}^3$; SD, standard deviation.

^aSelf-reported (diagnosed/medication for).

^bIn 1993.

^cAmong 21,403 participants with available air pollution data at the year of cohort entry.

^dAmong 22,715 participants with available road traffic noise data at the year of cohort entry.

^eAnnual weighted ($5\text{\hspace{0.17em}dB}$ penalty added to ${\mathrm{L}}_{\mathrm{e}}$ and $10\text{\hspace{0.17em}dB}$ penalty added to ${\mathrm{L}}_{\mathrm{n}}$) mean.