Best practices to reduce COVID-19 in group homes for individuals with serious mental illness and intellectual and developmental disabilities: Protocol for a hybrid type 1 effectiveness-implementation cluster randomized trial

Background: People with serious mental illness (SMI) and intellectual disabilities and/or developmental dis-abilities (ID/DD) living in group homes (GHs) and residential staff are at higher risk for COVID-19 infection, hospitalization, and death compared with the general population.Methods: We describe a hybrid type 1 effectiveness-implementation cluster randomized trial to assess evidence-based infection prevention practices to prevent COVID-19 for residents with SMI or ID/DD and the staff in GHs. The trial will use a cluster randomized design in 400 state-funded GHs in Massachusetts for adults with SMI or ID/DD to compare effectiveness and implementation of "Tailored Best Practices" (TBP) consisting of evidence-based COVID-19 infection prevention practices adapted for residents with SMI and ID/DD and GH staff; to "General Best Practices" (GBP), consisting of required standard of care reflecting state and federal standard general guidelines for COVID-19 prevention in GHs. External (i.e., community-based research staff) and internal (i.e., GH staff leadership) personnel will facilitate implementation of TBP. The primary effectiveness outcome is incident SARS-CoV-2 infection and secondary effectiveness outcomes include COVID-19-related hospitalizations and mortality in GHs. The primary implementation outcomes are fidelity to TBP and rates of COVID-19 vacci-nation. Secondary implementation outcomes are adoption, adaptation, reach, and maintenance. Outcomes will be assessed at baseline, 3-, 6-, 9-, 12-, and 15-months post-randomization.