Substance Use Patterns and Negative Urine Opioid Screen Among Patients on Methadone Treatment at a Referral Hospital in Nairobi, Kenya.

Abstract

Background Studies show concurrent substance use is common among patients with opioid use disorder. Despite evidence that various medications for Opioid Use Disorder are beneficial, some patients continue using opioids while in the program. We aimed to determine substance use patterns at enrolment and negative urine opioid screens among patients who were attending the Medically Assisted Therapy Clinic at a referral hospital in Nairobi.Methods This was a retrospective cohort study of 713 patients who had enrolled in the Medically Assisted Therapy clinic between December 2014 and February 2018. Data for each participant was collected over 24 months. A researcher-designed socio-demographic form and a data collection form were used to collect data. The data was analysed using Statistical Analysis for Data Science (STATA) version 18. 3.10.Results Most participants were male 85.7%, with a mean age of 34.3 years (SD 8.6). The majority had primary and below level of education 48.8%, were employed 59.5%, and were single/separated/widowed 78.4%. All the participants had used at least one other substance apart from opioids. The most common substances were; tobacco 91%, followed by cannabis 82.9% and benzodiazepines 51.5%. At 6, 12, 18, and 24 months, negative urine opioid screens were 61.3%, 76.0%, 73.5%, and 81.4%, respectively. At 24 months, 81.3% of the participants were still active in treatment.Conclusions Many of the patients attending the Medically Assisted Therapy clinic use more than one substance. There is a need to scale up the program to also offer free management for other substances. Many patients had a negative urine opioid screen at 24 months; this replicated the evidence for the efficacy of medications for Opioid Use Disorders. However, there is a need to further explore why some patients continue to use opioids while in the program.