COVID-19(15) disorder(14) Treatment(12) Opioid use disorder(11) medication(10) participant(9) conducted(9) Care(8) Community(8) COVID-19 pandemic(8) Result(8) Intervention(8) Substance use(8) Support(7) IMPROVE(7) risk(7) Patient(7) mental health(6) approach(6) harm reduction(5) measure(5) receiving(5) Self-efficacy(5) pilot study(5) approach(5) outcome(5) pandemic(5) reduction(5) supplementary material(5) majority(5)