Table 2.

Relative risk of columnar cell lesions by intensity of lifetime physical activity, Nurses' Health Study II, 1997–2001

Type of activity	Person-years	No. of CCL	Age-adjusted RR	Multivariable- adjusted RR (95% CI)
Strenuous, h/wk
<1.0	34803	26	1.00 (referent)	1.00 (referent)
1.0–1.9	40018	26	0.90	0.90 (0.52 to 1.56)
2.0–2.9	32244	17	0.75	0.75 (0.40 to 1.39)
3.0–3.9	21928	15	1.01	1.00 (0.53 to 1.92)
≥4.0	32814	13	0.60	0.62 (0.31 to 1.22)
Ptrend					0.08
Moderate, h/wk
<1.0	18591	17	1.00 (referent)	1.00 (referent)
1.0–1.9	41154	23	0.62	0.60 (0.32 to 1.13)
2.0–2.9	36281	20	0.62	0.60 (0.31 to 1.15)
3.0–3.9	25794	14	0.60	0.59 (0.29 to 1.20)
≥4.0	39987	23	0.67	0.66 (0.35 to 1.25)
Ptrend					0.83
Walking, h/wk
<0.5	30352	14	1.00 (referent)	1.00 (referent)
0.5–0.9	32234	24	1.48	1.47 (0.76 to 2.86)
1.0–1.4	28595	23	1.60	1.61 (0.82 to 3.14)
1.5–2.4	35704	16	0.88	0.88 (0.43 to 1.82)
≥2.5	34923	20	1.14	1.19 (0.60 to 2.38)
Ptrend					0.20
Total activity, MET-h/wk
<21.0	40240	32	1.00 (referent)	1.00 (referent)
21.0–29.9	31109	21	0.90	0.89 (0.51 to 1.55)
30.0–38.9	27793	12	0.57	0.56 (0.28 to 1.09)
39.0–53.9	30649	14	0.62	0.62 (0.33 to 1.18)
≥54.0	32016	18	0.78	0.80 (0.45 to 1.45)
Ptrend					0.22