Primary Care–Mental Health Integration in the VA Health System: Associations Between Provider Staffing and Quality of Depression Care

Data were obtained from the VA Corporate Data Warehouse (CDW) for the 349 VAMCs (N=166) or large CBOCs (N=183) falling under the policy requirement to implement PCMHI. The CDW contains patient demographic, diagnosis, procedure, clinical encounter, clinic type, and pharmacy data for all VA patients. Depression treatment measures were calculated for each facility from a cohort of 279,199 patients across these facilities who had a new episode of depression, defined by an index diagnosis of depression (ICD-9-CM codes 293.83, 296.2, 296.3, 296.9, 298.0, 300.4, 301.12, 309, and 311) (12) at a primary care or PCMHI clinic encounter in fiscal year 2013 and who did not have a depression diagnosis or antidepressant treatment in the 12 months prior to the index diagnosis date. Patients with a bipolar disorder diagnosis (296.0, 296.1, 296.4, 296.5, 296.6, 296.7, and 296.8) were excluded because antidepressant medications are not recommended as first-line treatments for bipolar depression, and thus indicators of antidepressant treatment do not apply to this population (13). Average patient characteristics per facility were used in analyses. These included average patient age, percentage of patients at the facility with an urban address, percentage of male patients, percentage of non-Hispanic white patients, percentage with a ≥70% military service–connected disability status, and percentage with a psychiatric comorbidity of a substance use disorder, posttraumatic stress disorder (PTSD), or other anxiety disorder. Facility characteristics used in analyses included the number of unique patients in primary care and facility type (VAMC or CBOC).

Across all 349 sites, 65% of the primary care patients with a new episode of depression received any antidepressant medication and 45% received adequate antidepressant medication. Twenty-seven percent of cohort patients received any psychotherapy in the three months following their depression diagnosis, and 11% engaged in psychotherapy (defined as attending three or more psychotherapy sessions (Table 1). Table 1 also presents facility characteristics and average patient characteristics for primary care patients with a new episode of depression. On average, facilities reported 2.3 clinical PCMHI FTEs per 10,000 primary care patients.

This study investigated the relationship between PCMHI staffing characteristics and the quality-of-care processes among VA patients given a diagnosis of depression by PCPs or PCMHI providers. Overall, higher levels of PCMHI clinical provider FTEs per 10,000 patients were associated with higher rates of psychotherapy receipt but were not associated with antidepressant medication receipt. The positive association between quality of psychotherapy for depression and total PCMHI provider staffing is particularly notable considering that PCMHI is provided in addition to the VA health system’s comprehensive specialty mental health services that are often located in the same facility as primary care. Higher PCMHI proportions of social workers were associated with higher receipt of adequate antidepressant medication, and higher proportions of nurses in PCMHI were associated with less psychotherapy engagement. These results suggest that PCMHI staffing may influence the extent to which improvements in the quality of care for depression are realized.

The finding that total PCMHI FTEs were not associated with higher rates of medication use may be related to the fact that the proportion of staff who were psychiatric prescribers (for example, psychiatrists and nurse practitioners) was not significantly related to receipt of or adherence to antidepressant medication. These findings were surprising and not consistent with initial hypotheses. One explanation may be that the function of psychiatric prescribers may overlap with functions of primary care providers, who often prescribe antidepressant medications without specialty prescriber input (17,18). It is also possible that the addition of a psychiatric prescriber to PCMHI does not provide a marginal benefit relative to the availability of psychiatric prescribers in VA specialty mental health settings. Psychiatric medication prescribers also often have a supervisory or consultative role in collaborative care models, which may limit their ability to directly affect patient adherence compared with the other disciplines. This finding is consistent with a prior VA study, which found that a psychiatric resident consultation service was not as effective as a care management model in improving depression care (6). This finding, however, is in contrast to a meta-regression analysis of collaborative care trials, which found that care management that included supervision by a psychiatrist was associated with better outcomes (5). Further investigation is needed to determine the role of psychiatric prescribers in VA PCMHI services and the extent to which they operate in a traditional referral-based consultant model or serve as supervisors of care managers, who care for a larger number of patients.

Proportions of registered nurses in PCMHI services were also not associated with receipt of antidepressant medication. One explanation for this finding may be that in 2010 the VA began national implementation of patient-centered medical homes (19), of which nurse care management is a key component (19,20). Thus primary care nurses may provide care management functions for psychiatric medications that overlap with services provided by PCMHI nurses. However, the proportion of social workers, who also often serve as care managers, was associated with greater antidepressant treatment adequacy. Although we did not specifically test for differences between the two disciplines, the contrast in findings could indicate that nurses in PCMHI programs may need more specific training to engage patients in continued mental health treatment. Data from the Canadian Community Health Survey indicated that patient dropout (defined by leaving mental health treatment before the provider agreed to termination) over a 12-month period was most likely for those who had seen a nurse but was less likely for those who had seen a social worker or psychologist (21). In addition, in a meta-analysis of collaborative care interventions, care managers with a specific mental health background were more effective than those without (5). The degree of prior mental health experience, if different across disciplines of care managers, could influence the relationship between discipline-specific staffing and care quality.

The finding that PCMHI program staffing was associated with greater psychotherapy receipt but not with greater antidepressant treatment adequacy could be related to the fact that psychologists are the most common discipline within VA PCMHI programs. Social workers, the second most common discipline, also often provide psychotherapy. The proportion of psychologists or social workers was not associated with greater receipt of psychotherapy, suggesting that programs in which most staff were either psychologists or social workers performed similarly in terms of delivering psychotherapy. Staffing by nurses, who generally do not provide psychotherapy, was associated with less receipt of psychotherapy. Increased delivery of psychotherapy in primary care may represent a more patient-centered approach to depression treatment (22). However, although there is evidence to support the effectiveness of brief psychotherapy for depression outside a PCMHI model, meta-analysis of controlled trials has not shown psychotherapy to be an effective augmentation to antidepressant treatment provided as part of collaborative depression care (5). The incorporation of depression outcome data into quality measurement could help clarify the balance in staffing between psychotherapy providers versus medication care managers (and their supervisors) to optimally improve population-level depression outcomes.

This study had several limitations, and certain conclusions should be circumscribed. First, although we investigated psychotherapy receipt, we could not measure the type of psychotherapy received or fidelity to evidence-based protocols. We note, however, that psychotherapy in the VA is increasingly delivered according to evidence-based protocols (23,24). Second, the measure of antidepressant treatment quality assessed only the quantity of medication provided and did not assess other aspects of antidepressant medication management, such as adequate dosing, intensification, or management of side effects. Finally, the cross-sectional observational nature of the study limits the extent to which conclusions may be drawn about the causal role of PCMHI staffing in improving care. Although we adjusted for available patient and facility characteristics that may have confounded the relationship between staffing and care, it is possible that the analyses did not control for other important confounders. Future research should examine the implementation factors that account for differences in staffing and the causal effects of staffing interventions.

Integration of mental health services into primary care is an important way to improve mental health care access, engagement, and outcomes. This study found that total PCMHI staffing was associated with higher levels of psychotherapy receipt, and higher proportions of PCMHI social worker staffing were associated with better performance on measures of antidepressant treatment adequacy in VA integrated care programs. Future quality improvement efforts should examine fidelity to depression care management protocols given the lack of increase in antidepressant treatment associated with total staffing or staffing specifically by medication prescribers and nurse care managers. Findings from the VA’s extensive national implementation of PCMHI services may also inform work in other health systems.

This study was conducted as part of the VA Primary Care–Mental Health Integration National Evaluation (Dr. McCarthy, Ms. Cornwell, and Ms. Brockmann), in the VA Office of Mental Health Operations.