Table 4.

Interaction of Age at Menarche and Menstrual Characteristics with Physical Activity on Adult Onset Asthma

		Adult onset asthma		Stratified model		Joint model
Characteristics		Yes (N=257)	No (N=3151)	Adj. RR	95% (CI)	Adj. RR	95% (CI)
Physically active and age at menarche
Yes, >11 years		199 (78.97)	2576 (85.98)	Referent	Referent	Referent	Referent
Yes, ≤11 years		53 (21.03)	420 (14.02)	1.6	(1.19,2.15)	1.58	(1.18,2.13)
No, >11 years		7 (77.78)	173 (84.80)	Referent	Referent	0.56	(0.26,1.18)
No, ≤11 years		2 (22.22)	31 (15.20)	2.21	(0.51,9.59)	0.95	(0.24,3.65)
P-value for interaction							0.943
Physically active and menstrual regularity
Yes, regular menses		212 (86.18)	2556 (85.31)	Referent	Referent	Referent	Referent
Yes, irregular menses		34 (13.82)	440 (14.69)	Referent	(0.65, 1.32)	0.93	(0.65, 1.32)
No, regular menses		2 (22.22)	28 (13.73)	Referent	Referent	0.52	(0.25,1.10)
No, irregular menses		7 (77.78)	176 (86.27)	1.11	(0.22,5.67)	0.89	(0.23,3.41)
P-value for interaction							0.668
Physically active and usual cycle length
Yes,<36 days		7 (77.78)	186 (91.63)	Referent	Referent	Referent	Referent
Yes,≥36days		2 (22.2)	17 (8.37)	2.51	(0.58, 10.77)	2.83	(0.63,12.68)
No, <36days		224 (91.06)	2758 (92.55)	Referent	Referent	2.80	(0.95, 4.18)
No, ≥36 days		22 (8.94)	222 (7.45)	1.16	(0.76,1.78)	2.33	(1.01,5.36)
P-value for interaction							0.262

Adjusted for age, race/ethnicity, BMI at age 18, educational status, smoking, parity, history of diabetes and history of hypertension, * physical activity for teen years (13– 17) years