Analyzing the impact of a state concussion law using an autoregressive integrated moving average intervention analysis

Table 2 Rate of concussion-related medical encounters per 10,000 member months from 2008 to 2016, autoregressive integrated moving average (ARIMA) intervention models with three breakpoints

Concussion Law Intervention Breakpoints		Change			ARIMA model and noise*
Concussion Law Intervention Breakpoints		Percentage of Change	95% CI	P	Specification	Q24a	P
Period 1	Feb,2010	3.6	−4.0 to 11.8	0.3628	(0,1,1)(2,1,0)₁₂	20.13	0.58
Period 2	July,2011	7.3	1.1 to 13.7	0.0186	(0,1,1)(2,1,0)₁₂	21.70	0.48
Period 3	July,2013	2.0	− 4.4 to 8.8	0.5449	(0,1,1)(2,1,0)₁₂	22.70	0.42

*The Ljung-Box Portmanteau (or Q-) test was used to test the randomness of residuals of the estimated models

ISSN: 1472-6963