Table 2.

Univariate and multivariate cox-proportional hazard models for fractures.

Physical Activity Change	Number	Event	Duration (days)	Rate*	Model 1	Model 2	Model 3
Any Fracture
No → No	19,844	960	88,261	10.88	1 (reference)	1 (reference)	1 (reference)
No → Yes	15,652	642	70,658	9.09	0.834 (0.755,0.922)	0.965 (0.873,1.067)	0.967 (0.875,1.069)
Yes → No	11,849	500	52,948	9.44	0.868 (0.779,0.967)	0.942 (0.845,1.049)	0.942 (0.845,1.049)
Yes → Yes	27,429	822	121,698	6.75	0.621 (0.566,0.682)	0.844 (0.767,0.928)	0.848 (0.771,0.932)
Vertebral Fracture
No → No	19,844	345	89,901	3.84	1 (reference)	1 (reference)	1 (reference)
No → Yes	15,652	173	71,940	2.40	0.625 (0.521, 0.750)	0.777 (0.646,0.933)	0.779 (0.648,0.936)
Yes → No	11,849	164	53,878	3.04	0.793 (0.659, 0.955)	0.892 (0.741,1.075)	0.893 (0.741,1.076)
Yes → Yes	27,429	218	123,300	1.77	0.462 (0.390, 0.547)	0.698 (0.587,0.830)	0.703 (0.591,0.836)
Hip Fracture
No → No	19,844	48	90,631	0.53	1 (reference)	1 (reference)	1 (reference)
No → Yes	15,652	24	72,327	0.33	0.623 (0.382,1.017)	0.844 (0.515,1.381)	0.861 (0.526,1.410)
Yes → No	11,849	30	54,236	0.55	1.045 (0.662,1.649)	1.230 (0.778,1.944)	1.211 (0.766,1.916)
Yes → Yes	27,429	15	123,773	0.12	0.231 (0.129,0.412)	0.393 (0.218,0.711)	0.405 (0.224,0.732)

Model 1, crude; Model 2, adjusted for age and sex; Model 3, adjusted for age, sex, diabetes, hypertension, hyperlipidemia, chronic kidney disease, low income, and type of thyroidectomy; *Rate; incidence rates per 1000 person years