Table 2

Interrupted time series model estimates for monthly rates of cannabis use disorders (Indicator 1) and poisoning/adverse effects of psychodysleptics (Indicator 2) per 1000 visits across the ICD-9-CM to ICD-10-CM transition

Indicator 1: Cannabis use disorders†Indicator 2: Poisoning and adverse effects of psychodysleptics‡
EDHospitalisationsEDHospitalisations
Intercept5.8142*12.5588*0.2204*0.2387*
Time (slope)0.03820.0698*−0.00230.0031
Adult use cannabis legal slope change (Nov 2012)0.2525*0.3673*0.0198*0.0008
Adult use cannabis sales slope change (pre-transition) (Jan 2014)−0.4559*0.1385*−0.021*0.0005
Level change at transition (Oct 2015)1.9228*1.759*−0.01060.0777
Post-transition slope change0.2385*−0.5424*0.0125*−0.0021
  • Data source: Colorado Hospital Association, 1 January 2011 to 31 December 2018.

  • *p<0.05.

  • †Indicator 1: Cannabis use disorders included ICD-9-CM codes 304.3X and 305.2X and all ICD-10-CM F12 codes.

  • ‡Indicator 2: Poisoning and adverse effects of psychodysleptics included ICD-9-CM codes 969.6, E854.1 and E939.6, and ICD-10-CM codes T40.7X1A-T40.7X5A, T40.8X1A-T40.8X4A, T40.901A-T40.905A and T40.991A-T40.995A.

  • ED, emergency department; ICD-9-CM, International Classification of Diseases, 9th Revision, Clinical Modification; ICD-10-CM, International Classification of Diseases, 10th Revision, Clinical Modification.