This study utilizes a novel approach to analyzing the many components of the HIV MDCT on ART adherence. We determined that several MDCT combinations had a positive influence on adherence, compared to the HIV/ID specialist alone. Although we did not see a consistent improvement in odds BLQ or new AIDS events among the groups found significantly associated with improved adherence compared to the HIV specialist only, we did see with the clinical pharmacist plus non-HIV specialized primary care a significant increase in CD4+ counts through 360 days of follow-up.
Our finding that team members other than the HIV specialist would have a significant impact on ART adherence is supported by prior studies indicating that doctors do not necessarily emphasize adherence in their patient interactions, including HIV providers.37
Clinical pharmacists are trained to help patients manage and adhere to complex medication regimens.38, 39
In an earlier study, we showed that clinical pharmacists improved adherence and decreased outpatient office visits among both antiretroviral naïve and experienced patients.32, 40
Our earlier research with HIV clinical pharmacists also indicated that there was an interaction with provider experience, prompting us to initiate this study.
The potential MDCT combinations shown here associated with improved adherence are consistent with the literature. Earlier studies indicate that nurses improve patient adherence knowledge.41
The nurse case manager and social worker have different scopes of practice, but each help address patient unmet needs, which should improve the likelihood of being adherent to medications. The same reasoning would apply to the clinical pharmacist plus the social worker or plus the non-nurse care coordinator. The HIV specialist and mental health worker could address different significant impacts on the patient’s ability to adhere to treatment plans and regimens. Of course, another primary outcome (like care retention) may derive different results.
We did not specifically designate a case manager among our MDCT components of interest, as many different personnel in KP function in that role, including the nurse, non-nurse care coordinator, social worker, clinical pharmacist, or others, depending on the clinic’s structure. The ability of many different personnel to have the case manager role has made prior research in this area problematic.13, 42–44
However, the activities of case management in a medical system, including improving access to and retention in care, treatment plan adherence, and meeting unmet patient needs, 13, 45
are likely represented by the personnel found to be associated with improved adherence in this study—obviating the need for a specifically designated case manager in all clinics.
There is a lack of prior research on health educators, dieticians, and social work in the area of HIV MDCT and improved outcomes.13, 14, 18, 19
We found improved adherence with the social worker when combined with both the nurse and the clinical pharmacist, demonstrating a likely synergy of roles. Given the many tasks that social workers provide (including arranging housing, transportation, insurance benefits and medication availability), our results are not surprising. We were disappointed to find that neither dieticians nor health educators were specifically associated with improved adherence, but it is possible that their services could be associated with improving other HIV-related outcomes.
We acknowledge a few limitations to our study. A small percent of patients (< 5%) do not receive their medications through our pharmacies. It is possible that their adherence results could be quite different, but this is unlikely. It also is possible that some patients use outside case management services and the impact of those services are not considered adequately, but this likelihood is quite low with our total integrated care system. As with all observational studies, there could be residual confounding, but we have accounted for the most significant factors in ART adherence and even account for provider and system level factors, the contributions and interactions of which are rarely considered. Also, some patients could have self-selected which clinic to attend based on the MDCT composition, but most patients in KP select their clinic based on geography.
We likely see some confounding by indication in our results. This is especially true for mental health, as patients with mental health issues were likely referred to the mental health specialist (and medical centers where they were located); patients with mental health issues have previously been shown to have lower adherence.46
There are parts of the CART analysis where mental health was associated with reduced adherence, although it is unlikely that mental health providers would have such a negative impact n adherence. In fact, our prior research has shown that HIV+ patients with depression but on anti-depression (SSRI) medication had ART adherence similar to HIV+ patients without a depression diagnosis.46
This will require further study, but should not take away from the key findings of the study.
We employed a retrospective observational cohort design. We believe that this is justified as patient-MDCT component interaction is likely more than just assigned visit times (phone calls, “curbside” interactions as examples of unrecorded “visits”). Further, it is likely (and probably desirable) that there is ongoing “inter-component” education, leading to improved practices by all team members, and not just that single component; this would not be captured if only designated visits were used in our analysis. Ideally, a prospective clinic-based trial, comparing the different MDCT found significantly associated with improved adherence, should be the next step.
We accounted for common patient-level and medication-level factors associated with ART adherence, including age, gender, HIV risk, race/ethnicity, regimen class, and temporal trend.4
We have previously shown that more recent ART regimens may have a greater impact on adherence than provider experience.47, 48
However, it is clear that these factors do not account for all of the impact on ART adherence. Our work demonstrates that there is a significant and measurable impact of ecologic (system of care) factors on patient-level HIV-related outcomes. There is little research in HIV or other chronic conditions in this area. Our results demonstrate that there is great opportunity for care and health outcome improvement with such exploration. With United States healthcare reform, improving patient outcomes is a necessity, and often that starts with improved treatment adherence. Further, healthcare reform places a strong emphasis on the patient centered medical home.49
Optimized MDCT is a key element of the medical home model. We demonstrate options for such core parts of the medical home.
Our results have implications for the United States National HIV/AIDS Strategy (NHAS), released in 2010.50
A goal of NHAS is to increase the number of HIV+ Americans on ART and increase the percent with maximal viral control. While clinicians always will be the MDCT member who ultimately determines which patients should be on medications and which ART regimen to use, our results indicate that other team members have integral roles in ensuring that treatment’s success, including adherence and improved outcomes. However, in times of constrained revenues and expensive care (total HIV care costs can be over $24,000 per year),51
it is tempting to think that the solo practitioner or specialist is all that is needed. Our results would indicate otherwise. Further, some of the MDCT combinations discovered here may be less costly per year than just the specialist alone who might experience a higher rate of failed regimens due to poor ART adherence.52
CART analysis can be successfully employed to help discover potential optimal care teams for adherence-related outcomes. We believe that the methodology applied here should be investigated for other HIV-related outcomes; especially those found in NHAS and improved healthcare quality. For example, NHAS calls for increased accessing care at time of HIV diagnosis and increased retention in care. The HIV MDCT could be optimized through this methodology for such desirable outcomes.