Healthcare costs and use before and after opioid overdose in Veterans Health Administration patients with opioid use disorder

AIMS

To compare healthcare costs and use between United States (US) Veterans Health Administration (VHA) patients with opioid use disorder (OUD) who experienced an opioid overdose (OD cohort) and patients with OUD who did not experience an opioid overdose (non-OD cohort).

DESIGN

This is a retrospective cohort study of administrative and clinical data.

SETTING

The largest integrated national health-care system is the US Veterans Health Administration's healthcare systems.

PARTICIPANTS

We included VHA patients diagnosed with OUD from October 1, 2017 through September 30, 2018. We identified the index date of overdose for patients who had an overdose. Our control group, which included patients with OUD who did not have an overdose, was randomly assigned an index date. A total of 66 513 patients with OUD were included for analysis (OD cohort: n = 1413; non-OD cohort: n = 65 100).

MEASUREMENTS

Monthly adjusted healthcare-related costs and use in the year before and after the index date. We used generalized estimating equation models to compare patients with an opioid overdose and controls in a difference-in-differences framework.

FINDINGS

Compared with the non-OD cohort, an opioid overdose was associated with an increase of $16 890 [95% confidence interval (CI) = $15 611-18 169; P < 0.001] in healthcare costs for an estimated $23.9 million in direct costs to VHA (95% CI = $22.1 million, $25.7 million) within the 30 days following overdose after adjusting for baseline characteristics. Inpatient costs ($13 515; 95% CI = $12 378-14 652; P < 0.001) reflected most of this increase. Inpatient days (+6.15 days; 95% CI, = 5.33-6.97; P < 0.001), inpatient admissions (+1.01 admissions; 95% CI = 0.93-1.10; P < 0.001) and outpatient visits (+1.59 visits; 95% CI = 1.34-1.84; P < 0.001) also increased in the month after opioid overdose. Within the overdose cohort, healthcare costs and use remained higher in the year after overdose compared with pre-overdose trends.

CONCLUSIONS

The US Veterans Health Administration patients with opioid use disorder (OUD) who have experienced an opioid overdose have increased healthcare costs and use that remain significantly higher in the month and continuing through the year after overdose than OUD patients who have not experienced an overdose.

Cost-effectiveness of Treatments for Opioid Use Disorder

IMPORTANCE

Opioid use disorder (OUD) is a significant cause of morbidity and mortality in the US, yet many individuals with OUD do not receive treatment.

OBJECTIVE

To assess the cost-effectiveness of OUD treatments and association of these treatments with outcomes in the US.

DESIGN AND SETTING

This model-based cost-effectiveness analysis included a US population with OUD.

INTERVENTIONS

Medication-assisted treatment (MAT) with buprenorphine, methadone, or injectable extended-release naltrexone; psychotherapy (beyond standard counseling); overdose education and naloxone distribution (OEND); and contingency management (CM).

MAIN OUTCOMES AND MEASURES

Fatal and nonfatal overdoses and deaths throughout 5 years, discounted lifetime quality-adjusted life-years (QALYs), and costs.

RESULTS

In the base case, in the absence of treatment, 42 717 overdoses (4132 fatal, 38 585 nonfatal) and 12 660 deaths were estimated to occur in a cohort of 100 000 patients over 5 years, and 11.58 discounted lifetime QALYs were estimated to be experienced per person. An estimated reduction in overdoses was associated with MAT with methadone (10.7%), MAT with buprenorphine or naltrexone (22.0%), and when combined with CM and psychotherapy (range, 21.0%-31.4%). Estimated deceased deaths were associated with MAT with methadone (6%), MAT with buprenorphine or naltrexone (13.9%), and when combined with CM, OEND, and psychotherapy (16.9%). MAT yielded discounted gains of 1.02 to 1.07 QALYs per person. Including only health care sector costs, methadone cost $16 000/QALY gained compared with no treatment, followed by methadone with OEND ($22 000/QALY gained), then by buprenorphine with OEND and CM ($42 000/QALY gained), and then by buprenorphine with OEND, CM, and psychotherapy ($250 000/QALY gained). MAT with naltrexone was dominated by other treatment alternatives. When criminal justice costs were included, all forms of MAT (with buprenorphine, methadone, and naltrexone) were associated with cost savings compared with no treatment, yielding savings of $25 000 to $105 000 in lifetime costs per person. The largest cost savings were associated with methadone plus CM. Results were qualitatively unchanged over a wide range of sensitivity analyses. An analysis using demographic and cost data for Veterans Health Administration patients yielded similar findings.

CONCLUSIONS AND RELEVANCE

In this cost-effectiveness analysis, expanded access to MAT, combined with OEND and CM, was associated with cost-saving reductions in morbidity and mortality from OUD. Lack of widespread MAT availability limits access to a cost-saving medical intervention that reduces morbidity and mortality from OUD. Opioid overdoses in the US likely reached a record high in 2020 because of COVID-19 increasing substance use, exacerbating stress and social isolation, and interfering with opioid treatment. It is essential to understand the cost-effectiveness of alternative forms of MAT to treat OUD.

Differences in body mass index based on self-reported versus measured data from women veterans

OBJECTIVE

The objective was to compare differences in body mass index (BMI) calculated with self-reported versus clinically measured pre-conception data from women veterans in California.

METHODS

Veterans Health Administration (VHA) and California state birth certificate data were used to develop a cohort of women who gave birth from 2007-2012 and had VHA data available to calculate BMI (N = 1,326 mothers, 1,473 births). Weighted Kappa statistics assessed concordance between self-reported and measured BMI. A linear mixed-effects model with maximum likelihood estimation, adjusted for mother as a random effect, assessed correlates of differences in BMI.

RESULTS

Mean BMI was in the overweight range based on self-reported (26.2 kg/m2, SD: 5.2) and measured (26.8 kg/m2, SD: 5.2) data. Weighted Kappa statistics indicated good agreement between self-reported and measured BMI (0.73, 95% CI: 0.70, 0.76). Compared to the normal weight group, groups with overweight or obesity were significantly more likely to have lower BMIs when calculated using self-reported versus measured heights and weights, in unadjusted and adjusted models. The finding was pronounced for class 3 obesity, which was associated with a BMI underestimation of 6.4 kg/m2.

CONCLUSIONS

Epidemiologic research that guides the clinical care of pregnant women should account for potential under-estimation of BMI in heavier women, and perform direct measurement where feasible.

Missing data strategies for time-varying confounders in comparative effectiveness studies of non-missing time-varying exposures and right-censored outcomes

The treatment of missing data in comparative effectiveness studies with right-censored outcomes and time-varying covariates is challenging because of the multilevel structure of the data. In particular, the performance of an accessible method like multiple imputation (MI) under an imputation model that ignores the multilevel structure is unknown and has not been compared to complete-case (CC) and single imputation methods that are most commonly applied in this context. Through an extensive simulation study, we compared statistical properties among CC analysis, last value carried forward, mean imputation, the use of missing indicators, and MI-based approaches with and without auxiliary variables under an extended Cox model when the interest lies in characterizing relationships between non-missing time-varying exposures and right-censored outcomes. MI demonstrated favorable properties under a moderate missing-at-random condition (absolute bias <0.1) and outperformed CC and single imputation methods, even when the MI method did not account for correlated observations in the imputation model. The performance of MI decreased with increasing complexity such as when the missing data mechanism involved the exposure of interest, but was still preferred over other methods considered and performed well in the presence of strong auxiliary variables. We recommend considering MI that ignores the multilevel structure in the imputation model when data are missing in a time-varying confounder, incorporating variables associated with missingness in the MI models as well as conducting sensitivity analyses across plausible assumptions.

Quality Of End-Of-Life Care Is Higher In The VA Compared To Care Paid For By Traditional Medicare

Congressional and Veterans Affairs (VA) leaders have recommended the VA become more of a purchaser than a provider of health care. Fee-for-service Medicare provides an example of how purchased care differs from the VA's directly provided care. Using established indicators of overly intensive end-of-life care, we compared the quality of care provided through the two systems to veterans dying of cancer in fiscal years 2010-14. The Medicare-reliant veterans were significantly more likely to receive high-intensity care, in the form of chemotherapy, hospital stays, admission to the intensive care unit, more days spent in the hospital, and death in the hospital. However, they were significantly less likely than VA-reliant patients to have multiple emergency department visits. Higher-intensity end-of-life care may be driven by financial incentives present in fee-for-service Medicare but not in the VA's integrated system. To avoid putting VA-reliant veterans at risk of receiving lower-quality care, VA care-purchasing programs should develop coordination and quality monitoring programs to guard against overly intensive end-of-life care.

Selection of Higher Risk Pregnancies into Veterans Health Administration Programs: Discoveries from Linked Department of Veterans Affairs and California Birth Data

OBJECTIVE

To describe variation in payer and outcomes in Veterans' births.

DATA/SETTING

Secondary data analyses of deliveries in California, 2000-2012.

STUDY DESIGN

We performed a retrospective, population-based study of all live births to Veterans (confirmed via U.S. Department of Veterans Affairs (VA) enrollment records), to identify payer and variations in outcomes among: (1) Veterans using VA coverage and (2) Veteran vs. all other births. We calculated odds ratios (aOR) adjusted for age, race, ethnicity, education, and obstetric demographics.

METHODS

We anonymously linked VA administrative data for all female VA enrollees with California birth records.

PRINCIPAL FINDINGS

From 2000 to 2012, we identified 17,495 births to Veterans. VA covered 8.6 percent (1,508), Medicaid 17.3 percent, and Private insurance 47.6 percent. Veterans who relied on VA health coverage had more preeclampsia (aOR 1.4, CI 1.0-1.8) and more cesarean births (aOR 1.2, CI 1.0-1.3), and, despite similar prematurity, trended toward more neonatal intensive care (NICU) admissions (aOR 1.2, CI 1.0-1.4) compared to Veterans using other (non-Medicaid) coverage. Overall, Veterans' birth outcomes (all-payer) mirrored California's birth outcomes, with the exception of excess NICU care (aOR 1.15, CI 1.1-1.2).

CONCLUSIONS

VA covers a higher risk fraction of Veterans' births, justifying maternal care coordination and attention to the maternal-fetal impacts of Veterans' comorbidities.

Effect of Interferon-Free Regimens on Disparities in Hepatitis C Treatment of US Veterans

OBJECTIVES

To determine whether implementation of interferon-free treatment for hepatitis C virus (HCV) reached groups less likely to benefit from earlier therapies, including patients with genotype 1 virus or contraindications to interferon treatment, and groups that faced treatment disparities: African Americans, patients with HIV co-infection, and those with drug use disorder.

METHODS

Electronic medical records of the US Veterans Health Administration (VHA) were used to characterize patients with chronic HCV infection and the treatments they received. Initiation of treatment in 206,544 patients with chronic HCV characterized by viral genotype, demographic characteristics, and comorbid medical and mental illness was studied using a competing events Cox regression over 6 years.

RESULTS

With the advent of interferon-free regimens, the proportion treated increased from 2.4% in 2010 to 18.1% in 2015, an absolute increase of 15.7%. Patients with genotype 1 virus, poor response to previous treatment, and liver disease had the greatest increase. Large absolute increases in the proportion treated were observed in patients with HIV co-infection (18.6%), alcohol use disorder (11.9%), and drug use disorder (12.6%) and in African American (13.7%) and Hispanic (13.5%) patients, groups that were less likely to receive interferon-containing treatment. The VHA spent $962 million on interferon-free treatments in 2015, 1.5% of its operating budget.

CONCLUSIONS

The proportion of patients with HCV treated in VHA increased sevenfold. The VHA was successful in implementing interferon treatment in previously undertreated populations, and this may become the community standard of care.

Mapping MOS-HIV to HUI3 and EQ-5D-3L in Patients With HIV

Objectives: The Medical Outcomes Study HIV Health Survey (MOS-HIV) is frequently used in HIV clinical trials; however, scores generated from the MOS-HIV are not suited for cost-effectiveness analyses as they do not assign utility values to health states. Our objective was to estimate and externally validate several mapping algorithms to predict Health Utilities Index Mark 3 (HUI3) and EQ-5D-3L utility values from the MOS-HIV. Methods: We developed and validated mapping algorithms using data from two HIV clinical trials. Data from the first trial (n = 367) formed the estimation data set for the HUI3 (4,610 observations) and EQ-5D-3L (4,662 observations) mapping algorithms; data from the second trial (n = 168) formed the HUI3 (1,135 observations) and EQ-5D-3L (1,152 observations) external validation data set. We compared ordinary least squares (OLS) models of increasing complexity with the more flexible two-part, beta regression, and finite mixture models. We assessed model performance using mean absolute error (MAE) and mean squared error (MSE). Results: The OLS model that used MOS-HIV dimension scores along with squared terms gave the best HUI3 predictions (mean observed 0.84; mean predicted 0.80; MAE 0.0961); the finite mixture model gave the best EQ-5D-3L predictions (mean observed 0.90; mean predicted 0.88; MAE 0.0567). All models produced higher prediction errors at the lower end of the HUI3 and EQ-5D-3L score ranges (<0.40). Conclusions: The proposed mapping algorithms can be used to predict HUI3 and EQ-5D-3L utility values from the MOS-HIV, although greater error may pose a problem in samples where a substantial proportion of patients are in poor health. These algorithms may be useful for estimating utility values from the MOS-HIV for cost-effectiveness studies when HUI3 or EQ-5D-3L data are not available.

Cost-Effectiveness of Treatments for Genotype 1 Hepatitis C Virus Infection in non-VA and VA Populations

Background: Chronic hepatitis C viral (HCV) infection affects millions of Americans. Health care systems face complex choices between highly efficacious, costly treatments. This study assessed the cost-effectiveness of treatments for chronic, genotype 1 HCV monoinfected, treatment-naïve individuals in the Department of Veterans Affairs (VA) and general US health care systems. Methods: The study used a decision-analytic Markov model, employing appropriate payer perspectives and time horizons, and discounting benefits and costs at 3% annually. Interventions included the following: sofosbuvir/ledipasvir (SOF-LDV); ombitasvir/paritaprevir/ritonavir/dasabuvir (3D); sofosbuvir/simeprevir (SOF-SMV); sofosbuvir/pegylated interferon/ribavirin (SOF-RBV-PEG); boceprevir/pegylated interferon/ribavirin (BOC-RBV-PEG); and pegylated interferon/ribavirin (PEG-RBV). Outcomes were sustained virologic response (SVR), advanced liver disease, costs, quality adjusted life years (QALYs), and incremental cost-effectiveness. Results: SOF-LDV and 3D achieve high SVR rates, reducing advanced liver disease (>20% relative to no treatment), and increasing QALYs by >2 years per person. For the non-VA population, at current prices ($5040 per week for SOF-LDV; $4796 per week for 3D), SOF-LDV’s lifetime cost ($293,370) is $18,000 lower than 3D’s because of its shorter duration in subgroups. SOF-LDV costs $17,100 per QALY gained relative to no treatment. 3D costs $208,000 per QALY gained relative to SOF-LDV. Both dominate other treatments and are even more cost-effective for the VA, though VA aggregate treatment costs still exceed $4 billion at SOF-LDV prices of $3308 per week. Drug prices strongly determine relative cost-effectiveness for SOF-LDV and 3D; with price reductions of 20% to 30% depending on health system, 3D could be cost-effective relative to SOF-LDV. We currently lack head-to-head regimen effectiveness trials. Conclusions: New HCV treatments are cost-effective in multiple health care systems if trial-estimated efficacy is achieved in practice, though, at current prices, total expenditures could present substantial challenges.

Effect of management strategies and clinical status on costs of care for advanced HIV

OBJECTIVES

To determine the association between preexisting characteristics and current health and the cost of different types of advanced human immunodeficiency virus (HIV) care.

METHODS

Treatment-experienced patients failing highly active antiretroviral treatment (ART) in the United States, Canada, and the United Kingdom were factorial randomized to an antiretroviral-free period and ART intensification. Cost was estimated by multiplying patient-reported utilization by a unit cost.

RESULTS

A total of 367 participants were followed for a mean of 15.3 quarters (range 1-26). Medication accounted for most (61.8%) of the $26,832 annual cost. Cost averaged $4147 per quarter for ART, $1981 for inpatient care, $580 for outpatient care, and $346 for other medications. Cost for inpatient stays, outpatient visits, and other medications was 171% higher (P <.01) and cost of ART was 32% lower (P <.01) when cluster of differentiation 4 (CD4) count was <50 cells/μL compared with periods when CD4 count was >200 cells/μL. Some baseline characteristics, including low CD4 count, high viral load, and HIV from injection drug use with hepatitis C coinfection, had a sustained effect on cost.

CONCLUSIONS

The association between health status and cost depended on the type of care. Indicators of poor health were associated with higher inpatient and concomitant medication costs and lower cost for ART medication. Although ART has supplanted hospitalization as the most important cost in HIV care, some patients continue to incur high hospitalization costs in periods when they are using less ART. The cost of interventions to improve the use of ART might be offset by the reduction of other costs.

Health-related quality of life as a predictor of mortality among survivors of AKI

BACKGROUND AND OBJECTIVES

This study examined the relationship between health-related quality of life and subsequent mortality among AKI survivors treated with renal replacement therapy.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Multivariable Cox regression models were used to assess the associations between Health Utilities Index Mark 3 (HUI3) and ambulation, emotion, cognition, and pain scores at 60 days and all-cause mortality at 1 year in 60-day AKI survivors (n=439 with evaluable HUI3 assessments) from a randomized multicenter study comparing less- with more-intensive renal replacement therapies.

RESULTS

The median 60-day HUI3 index score was 0.32. Patients with evaluable HUI3 data who died between 60 days and 1 year (n=99) were more likely to have lower 60-day median HUI3 scores, higher comorbidity scores, and longer initial hospital stays, and they were more likely to be dialysis-dependent. A 0.1 higher HUI3 index score was associated with a 17% decrease (hazard ratio, 0.83; 95% confidence interval 0.77-0.89) in all-cause mortality after controlling for clinical risk factors. Similar associations were observed for HUI3 ambulation, emotion, cognition, and pain attribute scores.

CONCLUSIONS

Health-related quality of life measured by HUI3 is an independent predictor of mortality among survivors of AKI after adjusting for clinical risk variables. Poor ambulation and other health-related quality of life attributes are also associated with increased risk of death. Health-related quality of life may provide clinicians with additional information to help identify patients at high risk of mortality after AKI that required renal replacement therapy.

Effect of Treatment Interruption and Intensification of Antiretroviral Therapy on Health-Related Quality of Life in Patients with Advanced HIV

Background. The effect of antiretroviral therapy (ART) interruption or intensification on health-related quality of life (HRQoL) in advanced HIV patients is unknown. Objective. To assess the impact of temporary treatment interruption and intensification of ART on HRQoL. Design. A 2 x 2 factorial open label randomized controlled trial. Setting. Hospitals in the United States, Canada, and the United Kingdom. Patients. Multidrug resistant (MDR) HIV patients. Intervention. Patients were randomized to receive a 12-wk interruption or not, and ART intensification or standard ART. Measurements. The Health Utilities Index (HUI3), EQ-5D, standard gamble (SG), time tradeoff (TTO), visual analog scale (VAS), and the Medical Outcomes Study HIV Health Survey (MOS-HIV). Results. There were no significant differences in HRQoL among the four groups during follow-up; however, there was a temporary significant decline in HRQoL on some measures within the interruption group during interruption (HUI3 −0.05, P = 0.03; VAS −5.9, P = 0.002; physical health summary −2.9, P = 0.001; mental health summary −1.9, P = 0.02). Scores declined slightly overall during follow-up. Multivariate analysis showed significantly lower HRQoL associated with some clinical events. Limitations. The results may not apply to HIV patients who have not experienced multiple treatment failures or who have not developed MDR HIV. Conclusions. Temporary ART interruption and ART intensification provided neither superior nor inferior HRQoL compared with no interruption and standard ART. Among surviving patients, HRQoL scores declined only slightly over years of follow-up in this advanced HIV cohort; however, approximately one-third of patients died during the trial follow up. Lower HRQoL was associated with adverse clinical events.