HEDIS initiation and engagement quality measures of substance use disorder care: impact of setting and health care specialty.

Many health care systems track the HEDIS measures of initiation and engagement in substance use disorder (SUD) care. However, the impact of setting of care (inpatient vs. outpatient) and health care specialty (SUD, psychiatric, other) on the likelihood of patients meeting the initiation and engagement criteria are unknown. If the vast majority of initiation and engagement occurs within SUD specialty clinics, then these quality measures could be used to discriminate among and incentivize SUD clinic managers. However, if these criteria are satisfied in different settings and specialties, then they should be considered characteristics of the entire facility, rather than just specialty SUD units. Using a Markov model, the probabilities of advancing to treatment initiation and engagement given initial setting and specialty of care were estimated for 320,238 SUD-diagnosed Veterans Health Affairs (VA) patients. Patients in SUD specialty units progressed more often (diagnosis to initiation, initiation to engagement) than patients in other specialties. Progression through the criteria differed for inpatients vs. outpatients. Approximately 25% of initiation and over 40% of engagement occurred outside of SUD specialty care. VA patients who have contact with SUD specialty treatment have higher rates of advancing to initiation, and from initiation to engagement, compared to SUD-diagnosed patients in psychiatric or other medical locations. Even so, a substantial portion of initiation and engagement occurs outside of SUD specialty units. Therefore, these quality measures should be considered measures of facility performance rather than measures of the quality of SUD specialty care. The usual combining of inpatient and outpatient performance on these measures into overall facility scores clouds measurement and interpretation.