Earlier recreational sales linked to more AF, heart failure and MI admissions

ABSTRACT: To determine the association between legal recreational cannabis sales (hereafter ‘legalisation’) and cardiovascular hospitalisations. This study leverages a natural experiment wherein legalisation began earlier in the Western census region of the United States (January 2014) versus non-Western regions (November 2018). DESIGN: Using the National Inpatient Sample (NIS), we performed a difference-in-differences analysis of the association between legalisation and hospitalisation rates for six cardiovascular diagnoses, a positive control (cannabis-related diagnoses) and two negative control diagnoses (opioid-related and urinary stones). SETTING: US states before (2012–2013) and after (2014–2018) legalisation in the Western region PARTICIPANTS: Hospitalised individuals in the Western region had a median age of 51 years, 57% were female and 43% were non-white. In other regions, the median age was 55 years, 57% were female and 33% were non-white. EXPOSURE: Legal recreational cannabis sales. MAIN OUTCOMES AND MEASUREMENTS: Annual hospitalisations per capita for atrial fibrillation/flutter (AF), heart failure (HF), myocardial infarction (MI), ischaemic stroke, venous thromboembolism (VTE) and ventricular tachycardia (VT). RESULTS: In this fully adjusted analysis, each year of legalisation was associated with the following relative change in hospitalisation rates expressed as change in the incidence rate ratio (∆IRR): cannabis-related diagnoses (∆IRR 1.138, 95% CI 1.066 to 1.214, p<0.001), AF (∆IRR 1.023, 95% CI 1.010 to 1.035, p<0.001), HF (∆IRR 1.037, 95% CI 1.029 to 1.046, p<0.001), MI (∆IRR 1.031, 95% CI 1.014 to 1.048, p<0.001), ischaemic stroke (∆IRR 1.011, 95% CI 0.999 to 1.024, p=0.078), VTE (∆IRR 1.009, 95% CI 0.999 to 1.020, p=0.066) and VT (∆IRR 1.019, 95% CI 0.993 to 1.046, p=0.161). For falsification testing, there was no change in hospitalisations for urinary stones (∆IRR 1.006, 95% CI 0.986 to 1.027, p=0.535) or opioid-related diagnoses (∆IRR 0.966, 95% CI 0.927 to 1.006, p=0.091). CONCLUSIONS: Legalisation was associated with increased hospitalisations for AF, HF and MI. Global legalisation trends may result in epidemiologically and economically important increases in cardiovascular healthcare use.