Table 2. Interrupted Time-Series Analysis of Monthly Fall-Related Injury Among MA and Commercially Insured Enrollees (Comparison Group) From 2010 to 2015.

Group by agea	Before coverage (2010–2012)			After coverage (2013–2015)			Before vs after coverage
	Fall-related injury per 10 000 person-days (95% CI)b	Rate (95% CI)c	P valuec	Fall-related injury per 10 000 person-days (95% CI)b	Rate (95% CI)c	P valuec	Rate change (95% CI)	P value	P value for MA vs commercial rate change
65-69 y
MA (n = 3 547 378)	1.34 (1.31 to 1.37)	0.00 (−0.01 to 0.02)	.76	1.38 (1.33 to 1.42)	0.06 (0.03 to 0.09)	.001	0.05 (0.02 to 0.09)	.002	.06
Comparison (n = 815 567)	1.44 (1.41 to 1.48)	−0.02 (−0.04 to 0.00)	.05	1.40 (1.34 to 1.45)	−0.02 (−0.05 to 0.02)	.33	0.01 (−0.03 to 0.04)	.76
70-74 y
MA (n = 1 668 561)	1.50 (1.47 to 1.54)	0.02 (0.00 to 0.04)	.10	1.56 (1.52 to 1.59)	0.05 (0.02 to 0.07)	<.001	0.03 (0.00 to 0.06)	.08	.76
Comparison (n = 211 269)	1.62 (1.58 to 1.67)	0.00 (−0.02 to 0.03)	.91	1.57 (1.50 to 1.64)	0.04 (0.00 to 0.08)	.09	0.04 (−0.01 to 0.09)	.13
75-79 y
MA (n = 1 211 833)	1.84 (1.80 to 1.89)	0.03 (0.00 to 0.05)	.07	1.95 (1.90 to 1.99)	0.06 (0.03 to 0.09)	.001	0.03 (−0.01 to 0.07)	.13	.92
Comparison (n = 107 596)	1.98 (1.91 to 2.06)	−0.03 (−0.07 to 0.02)	.24	2.02 (1.90 to 2.13)	0.00 (−0.07 to 0.07)	.99	0.03 (−0.06 to 0.11)	.51
≥80 y
MA (n = 1 439 617)	3.20 (3.15 to 3.24)	0.04 (0.01 to 0.06)	.006	3.30 (3.23 to 3.37)	0.16 (0.11 to 0.20)	<.001	0.12 (0.07 to 0.17)	<.001	.04
Comparison (n = 118 640)	3.12 (2.99 to 3.25)	0.04 (−0.04 to 0.11)	.36	3.51 (3.39 to 3.63)	0.03 (−0.05 to 0.11)	.47	−0.01 (−0.11 to 0.10)	.91

Abbreviation: MA, Medicare Advantage.

^aSample size reflects total number from 2010 to 2015.

^bData from the first month of the period.

^cAll rate, rate changes, and P values reported were obtained from regression models that included fixed effects for month. The rate presents the change per month in the injury rate.