We examined factors associated with utilization as conceptualized by the Andersen model of healthcare utilization , which proposes that utilization is determined by predisposing need and enabling factors . We hypothesized that psychiatric comorbidity would be associated with greater use of health services, and that members with higher deductibles would be less likely to initiate SUD and psychiatry treatment but would have higher emergency department and inpatient utilization than those without deductibles. As with earlier studies , which indicate that SUD diagnosis is often precipitated by a critical event such as an ED visit, we expected that post diagnosis utilization would be highest in the period immediately following diagnosis but would likely decrease over time, although trajectories would vary by type of utilization. Knowing how these factors are associated with use of healthcare can be highly informative to future healthcare reform and behavioral health services research. Kaiser Permanente Northern California is an integrated healthcare system serving approximately 4 million members . The membership is racially and socioeconomically diverse and representative of the demographic of the geographic area . SUD treatment is provided in specialty clinics within KPNC, which patients can access directly without a referral. The group based treatment model is similar to outpatient treatment programs nationwide. Treatment sessions take place daily or four times a week, depending on severity, for nine weeks . Treatment in psychiatry includes assessment,vertical growing towers individual and group psychotherapy, and medication management . KPNC is not contracted to provide SUD care or intensive psychiatry treatment for Medicaid patients and those patients are referred to county providers. The University of California, San Francisco and Kaiser Permanente Northern California Institutional Review Boards approved the study and approved a waiver of informed consent.

We identified common chronic medical conditions , many of which are known to be associated with SUDs using ICD-9/10 codes recorded within the first year after initial enrollment. Conditions included asthma, atherosclerosis, atrial fibrillation, chronic kidney disease, chronic liver disease, chronic obstructive pulmonary disease, coronary disease, diabetes mellitus, dementia, epilepsy, gastroesophageal reflux, heart failure, hyperlipidemia, hypertension, migraine, osteoarthritis, osteoporosis and osteopenia, Parkinson’s disease or syndrome, peptic ulcer, and rheumatoid arthritis. Patients with chronic medical conditions utilize more health services than patients without such conditions , which may influence their decision to choose a plan with a lower deductible if given an option , so we included this covariate to control for confounding. Deductibles are features across different benefit plans, including commercial plans, but are more common in ACA benefit plans. The individual deductible limit is the amount the individual must pay outof-pocket for health expenses before eligibility for health plan benefits. At KPNC, there are many types of benefit plans that include deductibles. Patients with deductible plans that do not include SUD as a covered benefit are responsible for bearing the cost of those services until their deductible is reached, and/or the accumulating cost of copays for multiple visits as part of the SUD care model. We did not include type of insurance as a covariate due to its collinearity with deductible limits and enrollment via the ACA exchange . We summarized utilization data into 6-month intervals, and we examined trends in health service utilization over 36 months after patients received an SUD diagnosis with Chi-squared tests using 6-month intervals. Using multi-variable logistic regression, we examined associations between deductible limits, enrollment via the California ACA Exchange, membership duration, and psychiatric comorbidity; and the likelihood of utilizing health services in the 36-month follow-up period, controlling for patient demographic characteristics and chronic medical comorbidity.

We also evaluated whether enrollment via the California ACA exchange moderated the associations between deductible limits and the likelihood of utilization by adding interaction terms to the multi-variable models. We estimated the associations with deductible limits for each enrollment mechanism by constructing hypothesis tests and confidence intervals on linear combinations of the regression coefficients from these models. To account for correlation between repeated measures, we used the generalized estimating equations methodology . We censored patients at a given 6-month interval if they were not a member of KPNC during that time. We conducted a sensitivity analysis to determine whether high utilizers leaving the health system influenced the observed pattern of decreased utilization from the 0–6 month to the 6–12 month follow-up periods. Using Chi-squared tests, we compared utilization during the 0–6 month period between patients who remained in the cohort and patients who disenrolled from KPNC at 6–12 months. We hypothesized that if the censored group had greater utilization than the noncensored group, then there would be evidence of high utilizers leaving the health system. We also conducted Chi-squared tests to determine whether censorship was associated with deductible limits and enrollment mechanisms. We conducted all analyses using SAS v9.4. We assessed significance at a p-value < .05. This study examined longitudinal patterns of healthcare utilization among SUD patients and their relationships to key aspects of ACA benefit plans, including enrollment mechanisms and deductible levels. We anticipated that the increase in coverage opportunities that the ACA provided would bring high-utilizing patients into health systems, driving up overall use of healthcare. Consistent with prior studies of SUD treatment samples that have found elevated levels of healthcare utilization either immediately before or after starting SUD treatment , results of our longitudinal analysis showed that utilization among people with SUDs was highest immediately after initial SUD diagnosis at KPNC, and declined to a stable level in subsequent years.

This suggests that the initial high utilization may be temporary. Our sensitivity analysis suggested that this result was not due to high utilizers leaving the KPNC healthcare system. This overall trend in utilization is a welcome finding, and consistent with the intent of the ACA to increase access to care; however, the subsequent decrease in utilization could also signify that patients are disengaging from treatment. Although we cannot specifically attribute the initial levels of utilization to lack of prior insurance coverage, as we did not have data on prior coverage, we found that individuals with fewer than 6 months of membership before receiving an SUD diagnosis were more likely to utilize primary care and specialty SUD treatment than those who had 6–12 months of membership. This suggests that future healthcare reforms that expand insurance coverage for people with SUDs might also lead to short-term increases in utilization for a range of health services. Deductibles are a key area of health policy interest given the growing number of people enrolling in deductible plans post-ACA. As anticipated, higher deductibles had a generally negative association with utilizing healthcare in this population. We found that patients with high deductibles had lower odds of using primary care, psychiatry, inpatient, and ED services than those without deductibles. Additionally, we found the associations between high deductibles and likelihood of utilizing primary care and psychiatry were strongly negative among ACA Exchange enrollees. Although it is somewhat difficult to gauge the clinical significance of these specific results,vertical growing racks the strength of the odds ratios for primary care and psychiatry access gives some indication of the potential impact. The associations of high deductibles with primary care and psychiatry access is worrying given the extent of medical and psychiatric comorbidities among people with SUDs . Although we found more consistent associations for higher deductibles and less healthcare initiation, it is possible that even a modest deductible could deter patients from seeking treatment . From a public policy and health system perspective, the possibility that deductibles could prevent people with SUDs from accessing any needed medical care is a cause for concern. Consistent with prior findings , our results suggest that high deductibles have the potential to dissuade SUD patients from accessing needed health services, and that those who enroll via the ACA exchange may be more sensitive to them. This could be attributable to greater awareness of coverage terms due to the mandate that exchange websites offer clear, plain-language explanations to compare insurance options . In contrast, high deductibles were associated with a greater relative likelihood of SUD treatment utilization. However, this association existed only among patients who enrolled via mechanisms other than the ACA Exchange. It is possible that individuals with emerging or unrecognized substance use problems may have selected higher deductible plans at enrollment due to either not anticipating use of SUD treatment, which is often more price-sensitive relative to other medical care , or not being aware of the implications of deductibles. However, once engaged in treatment, individuals with high deductibles may have been motivated to remain there. A contributing factor could also be that such patients were required to remain in treatment either by employer or court mandates, which are common and are associated with retention . The varying associations between deductibles and different types of health service utilization by enrollment mechanisms highlight the need for future research in this area. Insurance exchanges provide access to tax credits, a broader range of coverage levels, and information to assist in healthcare planning that might be less easily accessible through other sources of coverage, e.g., through employers . In our sample, Exchange enrollment was associated with greater likelihood of remaining a member of KPNC, did not demonstrate an adverse association with routine care, and was associated with lower ED use.

However, primary care and psychiatric services use were similar across enrollment types, even within low and high deductible limits. Prior studies have found that health plans offered through the ACA Exchange are more likely to have narrow behavioral health networks compared to other non-Exchange plans and primary care networks , which raises concerns about treatment access. For this health system, that concern appears unfounded. Psychiatric comorbidity was associated with greater service use of all types. Several prior studies have also found that patients with psychiatric comorbidity use more health services than those with SUD alone . Similar to our results, a recent study based in California found that after controlling for patient-level characteristics, the strongest predictors of frequent ED use post-ACA included having a diagnosis of a psychiatric disorder or an SUD . While the ACA was not expected to alter this general pattern, the inclusion of mental health treatment as an essential benefit was intended to improve availability of care and to contribute to efforts to reduce unnecessary service utilization. Our investigation confirms the ongoing importance post-ACA of psychiatric comorbidity and suggests that future efforts in behavioral health reform must anticipate high demand for healthcare in this vulnerable clinical population. It is also worth noting that nonwhite patients were less likely to initiate SUD and psychiatry treatment. Race/ethnic disparities in access to care are a longstanding concern in the addiction field . Some expected these disparities to be mitigated postACA . Findings on race/ethnic differences are similar to what has been observed in other health systems ; although, few studies have examined associations post-ACA. One prior study among young adults with SUD and psychiatric conditions post-ACA found modest ethnic disparities in lack of coverage between whites and other ethnic groups ; although, another study of young people more broadly found larger gains in coverage among Hispanics and Blacks relative to whites . The race/ethnic disparities in SUD and psychiatry treatment initiation in this cohort, in which overall insurance coverage was not a barrier but specific mechanisms could be, highlight the importance of addressing this complicated challenge to health equity. Alcohol use disorders are a major public health problem and constitute the most prevalent forms of addiction in veterans.Cognitive impairment is well-documented in individuals with alcohol use disorders,and alcohol-related clinical outcomes are moderated by a range of cognitive impairments.Cognition plays an important role in clinical outcomes, yet recognizing and screening for cognitive impairment in addiction populations remains uncertain and difficult.A comprehensive neurocognitive evaluation may not be routinely feasible in addiction settings, as these evaluations are often time intensive and resource consuming.When managing veterans with alcohol use disorders, quicker adjunctive tools that clinicians could use to screen for those individuals at higher risk of cognitive impairment are needed. One potential tool that may fulfill this role is the alcohol use biomarker. Alcohol use biomarkers are broadly divided into indirect and direct biomarkers.The indirect biomarkers include aspartate aminotransferase , alanine aminotransferase , mean corpuscular volume , γ-glutamyltransferase , and carbohydrate-deficient transferrin .