The prevalence and characteristics of moderate- to high-risk regulated and unregulated substance use among patients admitted to four public hospitals in Tshwane, South Africa.

Background: Alcohol, tobacco and unregulated substance use contributes to the global burden of disease. Admission to hospital provides an opportunity to screen patients for substance use and offer interventions.

Objectives: To determine the prevalence and nature of substance use and treatment as well as interest in harm reduction among inpatients from four hospitals in the City of Tshwane, South Africa.

Methods: In a cross-sectional study, sociodemographic and substance use data were collected from 401 patients using the World Health Organization's Alcohol, Smoking and Substance Involvement Screening Test. Demographic characteristics were analysed using descriptive statistics. Bivariate and multivariate analyses of moderate- to high-risk tobacco and unregulated substance use in relation to demographic characteristics were also done.

Results: Most patients were South African (88%) and black African (79%), over half were female (57%), and they were relatively young (median age 38 years). Most (82%) lived in formal housing. Over half (56%) had completed high school, and 33% were formally employed. Bivariate analysis found substance use-related admission to be higher where scores for tobacco and unregulated substance use were moderate to high (13% v. 0.3%, p<0.05). A notably higher (p<0.1) proportion of participants with no/low tobacco and unregulated substance use had completed high school, were employed and were cohabiting/married compared with those with moderate to high scores. Across the hospitals, 32% (129/401) of the participants had moderate- to high-risk use of at least one substance: tobacco (28%, 111/401), alcohol (10%, 40/401), cannabis (7%, 28/401), opioids (2%, 9/401) and sedatives (2%, 9/401). Of these 129 participants, 10% had accessed professional help, many (67%, 78/129) wanted to learn more about harm reduction, and most (84%, 108/129) said that they were willing to participate in a community-based harm reduction programme. Multivariate analysis found moderate- to high-risk tobacco and unregulated substance use to be positively associated with male sex (adjusted odds ratio (aOR) 7.9, 95% confidence interval (CI) 2.9 - 21.5), age <38 years (aOR 3.3, 95% CI 1.2 - 8.9), moderate- to high-risk alcohol use (aOR 3.1, 95% CI 1.1 - 8.4; p=0.027) and being admitted to Tshwane District Hospital (aOR 3.6, 95% CI 1.1 - 12.2). It was negatively associated with employment (aOR 0.2, 95% CI 0.1 - 0.6).

Conclusions: Moderate- to high-risk substance use is an undetected, unattended comorbidity in the hospital setting in Tshwane, particularly among young, single, unemployed men. Clinicians should identify and respond to this need. Further research is required on the implementation of in-hospital substance use screening and treatment interventions.