The period 1988–2005 marked a sharp reduction in methadone “under-dosing” practices among methadone-treatment units. Nonetheless, in 2005 only 44 percent of methadone patients in surveyed treatment units received doses of at least 80 mg/day—the threshold identified as recommended practice in recent work. Further, the NDATSS survey data show that between 2000 and 2005 the proportion of patients who received below 40 mg/day actually increased, though not significantly, from 13.5 to 17.1 percent.
We find other noteworthy differences from earlier results. JCAHO accreditation—an important variable in our prior analyses of 1988–2000 data—was much less important in the year 2005 data. Perhaps JCAHO accreditation is less important as a predictor of high methadone doses in 2005 because, as noted above, accreditation became mandated after 2000. As a result, methadone-treatment units that sought JCAHO accreditation before 2000 may differ substantially from units that only more recently were required to have either JCAHO or CARF accreditation. Specifically, it is possible that, compared with other units, the earlier wave of JCAHO-accredited units were more motivated to improve quality of care and were relatively resource-rich (e.g., in funds, staff, and training). These factors, either singly or in combination, may have enabled JCAHO-accredited units to be technology leaders that responded earlier to research documenting the benefits of high methadone doses.
The continuing strong tie between the proportion of a unit's patients who are from racial minority groups and methadone dose remains a concern. Units that treat a high percentage of African American patients are much more likely than units that treat a higher percentage of non-Hispanic whites to provide doses below recommended levels. Controlling for other factors in our most recent wave, each percentage-point increase in the proportion of African American clients was correlated with a 0.33 percentage-point increase in the proportion of patients receiving <60 mg/day, and with an even larger increase in the proportion of patients receiving <80 mg/day. This effect was large and statistically significant, and showed little decline from the results documented in earlier NDATSS survey waves.
Our differing point estimates in fixed-effect and random-effect specifications provides some evidence that nonwhite clients sort (or are sorted) into low-dosage units. We know of no clinical studies that demonstrate that nonwhite methadone patients systematically prefer or achieve better outcomes on low-dose treatment. Rather, it is more likely that common underlying weaknesses in treatment units are at work in our results. Units that provide low doses may lack human and financial resources (well-trained, well-paid, and stable work forces) or management systems (information systems; quality of care indicators and systematic checks of these) that contribute to their inability to meet care standards.
Examining this explanation should be a priority, especially in studies that are not limited—as ours is—by a lack of patient-level data. As noted, investigators have validated NDATSS data in several ways to ensure that our unit-level data are consistent with surveys of individual patient-level data. We cannot explore within-unit variation in service delivery or outcomes that may be correlated with patient-level variables. We also lack direct, patient-level measures of treatment outcomes.
We also find that managed care stringency is associated with lower methadone doses. Unit staff may be reluctant to provide high methadone doses to patients covered by managed care contracts simply because such a higher-dose course of treatment requires more time, and managed care shortens treatment duration. Indeed, there is evidence to support the link between higher methadone doses and longer treatment duration (e.g., Hubbard et al. 1989
) and between managed care and shorter treatment duration (Lemak and Alexander 2001
Finally, we are struck by the connection between managerial attitudes and methadone dose levels. Especially in our pooled sample, managers who support an abstinence orientation, who do not participate in HIV-prevention efforts, or who oppose syringe exchange are more likely to be in units that also provide low doses. After three decades of experience, basic differences and ambivalence about the proper goals of treatment continue to influence clinical practice, underscoring the contested role of methadone treatment for opiate disorders.