Interrupted time series design to evaluate the effect of the ICD-9-CM to ICD-10-CM coding transition on injury hospitalization trends

Table 1 Parameter estimates for segmented regression analysis of monthly injury hospitalization rates, January 2012–December 2017, by mechanism of injury

Mechanism of Injury	Time	ICD10CM	Time-after-ICD10CM
Cut/Pierce^a	− 0.004*	0.05	0.01*
Fall	0.04*	0.40	−0.05
Fire/Burn	−0.0002	− 0.09	0.0003
Firearm	0.001	−0.001	0.008*
Machinery^a	− 0.0004	0.05	−0.002
Motor Vehicle Traffic^a	− 0.03*	0.34	0.04*
Natural/Environmental^a	− 0.004*	0.05	0.001
Pedal cyclist, other^a	− 0.001	−0.06	− 0.0002
Poisoning^a	− 0.03*	1.29*	− 0.02
Struck by, against^a	− 0.006*	0.53**	− 0.002
Suffocation	0.001	0.08*	− 0.002
Other specified and classifiable^a	− 0.004*	0.001	0.004
Other specified, not elsewhere classifiable	0.001	−0.16**	− 0.002
Transportation, other^a	− 0.005*	0.75**	− 0.02*
Unspecified mechanism	0.002	0.29*	− 0.005

Notes: Each model had a significant intercept
*p < 0.05
**p < 0.001
^aThe final model included autoregressive parameter(s) significant at the 0.05 level

ISSN: 2197-1714