Table 3.

Associations between physical activity and incident myocardial infarction, stroke, and overall mortality among Nurses’ Health Study participants 1988–2008 ($N=\mathrm{104,990}$).

Outcome	Cases (n)	Person-years (n)	Basica HR (95% CI)	Fully adjustedb HR (95% CI)
Overall physical activity (MET h/wk)
MI or stroke
Q1: $<3.7$	2,248	405,352	Ref	Ref
Q2: 3.7–10.8	1,451	408,458	0.69 (0.64, 0.74)	0.74 (0.70, 0.80)
Q3: 10.9–24.3	1,281	409,422	0.61 (0.57, 0.65)	0.69 (0.64, 0.74)
Q4: $\ge 24.4$	1,094	408,780	0.53 (0.49, 0.57)	0.61 (0.57, 0.66)
p for trendc			$<0.0001$	$<0.0001$
Continuous (9 MET h/wk)	6,074	1,632,012	0.97 (0.96, 0.97)	0.98 (0.97, 0.98)
MI
Q1: $<3.7$	1,223	406,151	Ref	Ref
Q2: 3.7–10.8	803	408,970	0.69 (0.63, 0.76)	0.76 (0.70, 0.83)
Q3: 10.9–24.3	673	409,907	0.58 (0.53, 0.64)	0.68 (0.61, 0.74)
Q4: $\ge 24.44$	605	409,187	0.53 (0.48, 0.59)	0.64 (0.58, 0.71)
$p$ for trendc			$<0.0001$	$<0.0001$
Continuous (9 MET h/wk)	3,304	1,634,215	0.97 (0.96, 0.97)	0.98 (0.97, 0.98)
Stroke
Q1: $<3.7$	1,053	406,070	Ref	Ref
Q2: 3.7–10.8	668	408,996	0.68 (0.62, 0.75)	0.73 (0.66, 0.80)
Q3: 10.9–4.3	626	409,895	0.65 (0.59, 0.72)	0.71 (0.64, 0.78)
Q4: $\ge 24.4$	501	409,208	0.52 (0.47, 0.58)	0.58 (0.52, 0.65)
$p$ for trendc			$<0.0001$	$<0.0001$
Continuous (9 MET h/wk)	2,848	1,634,168	0.97 (0.96, 0.97)	0.97 (0.97, 0.98)
Overall mortality
Q1: $<3.7$	4,671	407,148	Ref	Ref
Q2: 3.7–10.8	2,193	409,645	0.51 (0.48, 0.54)	0.58 (0.55, 0.61)
Q3: 10.9–24.3	1,613	410,500	0.37 (0.35, 0.39)	0.45 (0.43, 0.48)
Q4: $\ge 24.4$	1,350	409,740	0.32 (0.30, 0.34)	0.40 (0.37, 0.42)
$p$ for trendc			$<0.0001$	$<0.0001$
Continuous (9 MET h/wk)	9,827	1,637,033	0.93 (0.93, 0.94)	0.95 (0.94, 0.95)
Walking (MET-hours/week)
MI or stroke
Q1: $<0.6$	2,094	338,605	Ref	Ref
Q2: 0.6–3.0	1,742	477,879	0.67 (0.63, 0.72)	0.72 (0.68, 0.77)
Q3: 3.1–9.9	1,166	386,251	0.55 (0.51, 0.59)	0.63 (0.58, 0.67)
Q4: $\ge 10.0$	1,072	429,278	0.49 (0.46, 0.53)	0.58 (0.54, 0.63)
p for trendc			$<0.0001$	$<0.0001$
Continuous (9 MET h/wk)	6,074	1,632,012	0.82 (0.80, 0.85)	0.87 (0.84, 0.90)
MI
Q1: $<0.6$	1,156	339,316	Ref	Ref
Q2: 0.6–3.0	934	478,540	0.64 (0.58, 0.69)	0.69 (0.63, 0.76)
Q3: 3.1–9.9	615	386,693	0.51 (0.46, 0.57)	0.60 (0.54, 0.66)
Q4: $\ge 10.0$	599	429,666	0.48 (0.43, 0.53)	0.58 (0.53, 0.65)
$p$ for trendc			$<0.0001$	$<0.0001$
Continuous (9 MET h/wk)	3,304	1,634,215	0.82 (0.79, 0.86)	0.88 (0.84, 0.92)
Stroke
Q1: $<0.6$	968	339,270	Ref	Ref
Q2: 0.6–3.0	826	478,504	0.71 (0.65, 0.78)	0.76 (0.69, 0.83)
Q3: 3.1–9.9	564	386,678	0.60 (0.54, 0.67)	0.66 (0.59, 0.73)
Q4: $\ge 10.0$	490	429,716	0.51 (0.45, 0.57)	0.58 (0.51, 0.65)
p for trendc			$<0.0001$	$<0.0001$
Continuous (9 MET h/wk)	2,848	1,634,168	0.83 (0.79, 0.87)	0.86 (0.82, 0.90)
Overall mortality
Q1: $<0.6$	4,679	340,313	Ref	Ref
Q2: 0.6–3.0	2,534	479,320	0.48 (0.46, 0.50)	0.54 (0.51, 0.57)
Q3: 3.1–9.9	1,511	387,203	0.35 (0.33, 0.37)	0.42 (0.39, 0.44)
Q4: $\ge 10.0$	1,103	430,197	0.27 (0.25, 0.29)	0.34 (0.32, 0.37)
p for trendc			$<0.0001$	$<0.0001$
Continuous (9 MET h/wk)	9,827	1,637,033	0.62 (0.59, 0.64)	0.69 (0.67, 0.71)
Vigorous physical activity (MET-hours/week)
MI or stroke
No vigorous activity	4,383	1,085,426	Ref	Ref
Any vigorous activity	1,691	546,586	0.83 (0.79, 0.88)	0.91 (0.86, 0.96)
Q1: $<1.4$	187	62,281	Ref	Ref
Q2: 1.4–6.2	739	210,781	1.01 (0.86, 1.19)	1.04 (0.88, 1.22)
Q3: 6.3–13.4	417	136,132	0.91 (0.76, 1.08)	0.96 (0.80, 1.14)
Q4: $\ge 13.5$	348	137,393	0.74 (0.62, 0.88)	0.80 (0.67, 0.96)
p for trendc			$<0.0001$	0.0001
Continuous (9 MET h/wk)	6,074	1,632,012	0.93 (0.89, 0.96)	0.94 (0.91, 0.97)
MI
No vigorous activity	2,401	1,086,969	Ref	Ref
Any vigorous activity	903	547,246	0.80 (0.74, 0.87)	0.89 (0.82, 0.96)
Q1: $<1.4$	106	62,344	Ref	Ref
Q2: 1.4–6.2	395	211,060	0.97 (0.78, 1.21)	0.99 (0.80, 1.23)
Q3: 6.3–13.4	220	136,302	0.86 (0.68, 1.08)	0.90 (0.71, 1.14)
Q4: $\ge 13.5$	182	137,540	0.69 (0.54, 0.88)	0.76 (0.59, 0.97)
p for trendc			$<0.0001$	0.002
Continuous (9 MET h/wk)	3,304	1,634,215	0.92 (0.87, 0.96)	0.94 (0.89, 0.98)
Stroke
No vigorous activity	2,038	1,086,970	Ref	Ref
Any vigorous activity	810	547,198	0.87 (0.80, 0.95)	0.93 (0.86, 1.01)
Q1: $<1.4$	82	62,358	Ref	Ref
Q2: 1.4–6.2	357	211,035	1.09 (0.86, 1.39)	1.11 (0.87, 1.42)
Q3: 6.3–13.4	201	136,278	0.99 (0.76, 1.28)	1.03 (0.79, 1.34)
Q4: $\ge 13.5$	170	137,527	0.81 (0.62, 1.06)	0.86 (0.66, 1.13)
p for trendc			0.003	0.01
Continuous (9 MET h/wk)	2,848	1,634,168	0.94 (0.89, 0.98)	0.95 (0.90, 0.99)
Overall mortality
No vigorous activity	7,467	1,088,968	Ref	Ref
Any vigorous activity	2,360	548,065	0.69 (0.66, 0.72)	0.77 (0.73, 0.81)
Q1: $<1.4$	303	62,453	Ref	Ref
Q2: 1.4–6.2	1,010	211,396	0.81 (0.71, 0.93)	0.83 (0.73, 0.94)
Q3: 6.3–13.4	566	136,492	0.75 (0.65, 0.86)	0.80 (0.69, 0.92)
Q4: $\ge 13.5$	481	137,723	0.61 (0.53, 0.70)	0.66 (0.57, 0.77)
p for trendc			$<0.0001$	$<0.0001$
Continuous (9 MET h/wk)	9,827	1,637,033	0.92 (0.90, 0.95)	0.94 (0.91, 0.97)

Note: CI, confidence interval; HR, hazard ratio; MET, metabolic equivalent of task; MI, myocardial infarction; Q, quartile; Ref, referent.

^aBasic model: adjusted for age and race (White yes/no).

^bFully adjusted model: additionally adjusted for incident cancer (yes/no), family history of myocardial infarction (yes/no), smoking status (never, past, current), pack-years, Alternate Healthy Eating Index score quartiles, alcohol consumption (0.0, $<5.0$, 5.0–9.9, 10.0–19.9, or $\ge 20.0\mathrm{g}/\mathrm{d}$), multivitamin use (yes/no), census tract median income (USD), census tract median home value (USD), occupation father (professional or other), occupation mother (housewife or other), husband’s level of education more than high school (yes/no), registered nursing degree in 1992 (yes/no), marital status (married or not married), retirement status (retired or not retired).

^cp for trend based on median quartile values.