Cannabis and cocaine use, drinking outcomes, and quality of life in general hospital inpatients with alcohol use disorder.

While associations between cannabis and cocaine use, and heavy drinking and quality of life (QOL), are well-established in the general population, it is unclear whether they are present in hospital inpatients with alcohol use disorder (AUD). The aim of the study was to assess associations between cannabis and cocaine use and two outcomes [heavy drinking days (HDDs) and QOL] among hospital inpatients with AUD. Hospitalized patients with AUD and at least one past-month HDD participated in this cross-sectional study. Cannabis and cocaine use were assessed using the Alcohol, Smoking, and Substance Involvement Screening Test. HDDs were assessed using the Timeline Followback. QOL was assessed by the WHOQOL-BREF instrument. Multivariable regression models assessed associations. Of 248 participants, 225 (91%) had severe AUD. There were no statistically significant associations between: recent cannabis use and HDDs [Incidence Rate Ratio (IRR) = 0.95; 95% Confidence Interval (95% CI): 0.80, 1.14], cocaine use and HDDs [IRR = 0.88; 95% CI: 0.66, 1.18], or both cannabis and cocaine use and HDDs [IRR = 0.87; 95%CI: 0.70, 1.09], as compared to use of neither cannabis nor cocaine. Use of cannabis, cocaine, and both, were not associated with QOL [(odds ratio (OR) = 0.98; 95% CI:0.55, 1.74), (OR = 0.76; 95% CI:0.30, 1.93), (OR = 1.00; 95%CI: 0.49, 2.03), respectively]. Among hospital inpatients with AUD, there were no significant associations between cannabis and cocaine use, heavy drinking, or QOL. Our findings raise questions regarding how drug use affects AUD and whether similar results would be found among those with milder AUD and in prospective studies.