Table 5.

Associations of Periodic limb movements and incident self-reported atrial fibrillation stratified by age

		Odds Ratio (95% Confidence Interval)
Predictor	N(%) Events	Unadjusted	Multivariable adjusted*
Periodic Limb Movement Index †
Age < 76 (n = 529)
<5 (n=172)	16 (9.30)	1.00 (reference)	1.00 (reference)
5 to <30 (n=157)	16 (10.19)	1.11 (0.53, 2.30)	0.94 (0.42, 2.10)
30+ (n=200)	18 (9.00)	0.96 (0.48, 1.96)	0.88 (0.39, 1.93)
p-trend across categories		0.91	0.74
Age ≥ 76 (n = 314)
<5 (n=86)	5 (5.81)	1.00 (reference)	1.00 (reference)
5 to <30 (n=80)	6 (7.50)	1.31 (0.39, 4.48)	1.27 (0.29, 5.52)
30+ (n=148)	24 (16.22)	3.14 (1.15, 8.55)	3.93 (1.17, 13.20)
p-trend across categories		0.01	0.01
Periodic Limb Movement Arousal Index
Age < 76 (n = 526)**
<1 (n=229)	23 (10.04)	1.00 (reference)	1.00 (reference)
1 to <5 (n=179)	16 (8.94)	0.88 (0.45, 1.72)	0.77 (0.37, 1.61)
5+ (n=118)	11 (9.32)	0.92 (0.43, 1.96)	0.70 (0.29, 1.69)
p-trend across categories		0.78	0.38
Age ≥ 76 (n = 310)
<1 (n=121)	6 (4.96)	1.00 (reference)	1.00 (reference)
1 to <5 (n=94)	17 (18.09)	4.23 (1.60, 11.21)	5.76 (1.76, 18.84)
5+ (n=95)	12 (12.63)	2.77 (1.00, 7.68)	2.46 (0.68, 8.89)
p-trend across categories		0.056	0.16

^*adjusted for clinic, age, race, body mass index, self-reported medical history (hypertension, diabetes mellitus, cardiovascular disease, stroke, and heart failure), cardiovascular medication use, pacemaker placement, alcohol use, estimated glomerular filtration rate cholesterol, and apnea-hypopnea index.

^†Interaction terms for both age as a continuous and categorical variable, p >=0.27

^**Interaction term for age as a continuous (p = 0.06) and categorical variable (p = 0.02)