Pharmaco-economics of community maintenance for opiate dependence: a review of evidence and methodology

Sharing the costs of structural interventions: What can models tell us?

BACKGROUND

The global HIV response needs to both integrate with the broader health system and tackle the structural drivers of HIV. Cross-sectoral financing arrangements in which different sectors agree to co-finance structural interventions - have been put forward as promising frameworks to address these concerns. However, co-financing arrangements remain rare for HIV, and there is no consensus on how to distribute costs.

METHODS

We use case studies to investigate how structural interventions can be incorporated within three quantitative decision-making frameworks. First, we consider cost-benefit analyses (CBA) using an opioid substitution therapy (OST) program in Armenia; second, we construct a theoretical example to illustrate the lessons game theory can shed on the co-financing arrangements implied by CBA; and third we consider allocative efficiency analyses using needle-syringe programs (NSPs) in Belarus.

RESULTS

A cross-sectoral cost-benefit analysis of OST in Armenia demonstrates that the share of that should be funded by the HIV sector depends on the willingness to pay (WTP) to avert an HIV-related DALY, the long-term cost-benefit ratio, and the HIV risk reduction from OST. For reasonable parameter values, the HIV sector's share ranges between 0-48%. However, the Shapley value--a game-theoretic solution to cost attribution that ensures each sector gains as much or more as they would from acting independently--implies that the HIV sector's share may be higher. In Belarus, we find that the HIV sector should be willing to co-finance structural interventions that would increase the maximal attainable coverage of NSPs, with the contribution again depending on the WTP to avert an HIV-related DALY.

CONCLUSION

Many interventions known to have cross-sectoral benefits have historically been funded from HIV budgets, but this may change in the future. The question of how to distribute the costs of structural interventions is critical, and frameworks that decision-makers use to inform resource allocations will need to take this into account.

Office-Based Buprenorphine Versus Clinic-Based Methadone: A Cost-Effectiveness Analysis

The objective of this analysis was to compare the cost-effectiveness of clinic-based methadone maintenance therapy (MMT) and office-based buprenorphine maintenance therapy (BMT) from the perspective of third-party payers in the United States. The authors used a Markov cost-effectiveness model. A hypothetical cohort of 1000 adult, opioid-dependent patients was modeled over a 1-year time horizon. Patients were allowed to transition between the health states of in opioid dependence treatment and either abusing or not abusing opioids, or to have dropped out of treatment. Probabilities were derived from randomized clinical trials comparing methadone and buprenorphine. Costs included drug and administration, clinic visits, and therapy sessions. Effectiveness outcomes examined were (1) retention in the treatment program and (2) opioid abuse-free weeks. For retention in treatment at 1 year, MMT was more costly ($4,613 vs. $4,155) and more effective (20.3% vs. 15.9%) than BMT, resulting in an incremental cost-effectiveness ratio (ICER) of $10,437 per additional patient retained in treatment. MMT was also more effective than BMT in terms of opioid abuse-free weeks (9.2 vs. 9.1 weeks), resulting in an ICER of $8,515 per opioid abuse-free week gained. One-way sensitivity analyses found costs per week of MMT to have the largest impact on the retention-in-treatment outcome, whereas the probability of dropping out with MMT had the greatest impact on opioid abuse-free weeks. The authors conclude that MMT is cost-effective compared with BMT for the treatment of patients with opioid dependence. However, the treatment of substance abuse is complex, and decision makers should also consider individual patient characteristics when making coverage decisions.

Assessing Differences in the Availability of Opioid Addiction Therapy Options: Rural Versus Urban and American Indian Reservation Versus Nonreservation

BACKGROUND

Opioid misuse is a large public health problem in the United States. Residents of rural areas and American Indian (AI) reservation/trust lands represent traditionally underserved populations with regard to substance-use disorder therapy.

PURPOSE

Assess differences in the number of opioid agonist therapy (OAT) facilities and physicians with Drug Addiction Treatment Act (DATA) waivers for rural versus urban, and AI reservation/trust land versus non-AI reservation/trust land areas in Washington State.

METHODS

The unit of analysis was the ZIP code. The dependent variables were the number of OAT facilities and DATA-waivered physicians in a region per 10,000 residents aged 18-64 in a ZIP code. A region was defined as a ZIP code and its contiguous ZIP codes. The independent variables were binary measures of whether a ZIP code was classified as rural versus urban, or AI reservation/trust land versus non-AI reservation/trust land. Zero-inflated negative binomial regressions with robust standard errors were estimated.

RESULTS

The number of OAT clinics in a region per 10,000 ZIP-code residents was significantly lower in rural versus urban areas (P = .002). This did not differ significantly between AI reservation/trust land and non-AI reservation/trust land areas (P = .79). DATA-waivered physicians in a region per 10,000 ZIP-code residents was not significantly different between rural and urban (P = .08), or AI reservation/trust land versus non-AI reservation/trust land areas (P = .21).

CONCLUSIONS

It appears that the potential for Washington State residents of rural and AI reservation areas to receive OAT is similar to that of residents outside of those areas; however, difficulties in accessing therapy may remain, highlighting the importance of expanding health care insurance and providing support for DATA-waivered physicians.

Factors Associated with Relapse among Heroin Addicts: Evidence from a Two-Year Community-Based Follow-Up Study in China

Background: Many countries including China are facing a serious opiate dependence problem. Anti-drug work effectiveness was affected by the high relapse rate all over the world. This study aims to analyze the factors influencing heroin addict relapse, and to provide evidence for generating relapse prevention strategies. Methods: A community-based follow-up study was conducted in China between October 2010 and September 2012. A total of 554 heroin addicts in accordance with the inclusion criteria from 81 streets in 12 districts of Shanghai, China were divided into 4 groups: group 1—daily dosage taken orally of 60 mL of methadone or under combined with psychological counseling and social supports (n = 130); group 2—daily dosage taken orally of over 60 mL of methadone combined with psychological counseling and social supports (n = 50); group 3—JTT (Jitai tablets) combined with psychological counseling and social supports (n = 206); group 4—JTT combined with social supports (n = 168). Results: Log-rank test results showed that the cumulative relapse rate differences among four groups during the two-year follow-up period were not statistically significant (χ² = 5.889, p = 0.117). Multivariate Cox regression analysis results showed that only three independent variables were still statistically significant, including compliance with participation in psychological counseling (OR = 3.563, p = 0.000), the years of drug use (OR = 1.078, p = 0.001)and intervention model. Conclusions: Using the detoxification medications combined with appropriate psychological counseling and social support measures will help improve the effectiveness of relapse prevention, which is a kind of alternative community detoxification pattern. Appropriate and standard psychological counseling is very important for anti-drug treatment. The longer the drug addiction lasts, the longer the anti-drug treatment takes.

The estimation of utility weights in cost-utility analysis for mental disorders: a systematic review

OBJECTIVE

To systematically review approaches and instruments used to derive utility weights in cost-utility analyses (CUAs) within the field of mental disorders and to identify factors that may have influenced the choice of the approach.

METHODS

We searched the databases DARE (Database of Abstracts of Reviews of Effects), NHS EED (National Health Service Economic Evaluation Database), HTA (Health Technology Assessment), and PubMed for CUAs. Studies were included if they were full economic evaluations and reported quality-adjusted life-years as the health outcome. Study characteristics and instruments used to estimate utility weights were described and a logistic regression analysis was conducted to identify factors associated with the choice of either the direct (e.g. standard gamble) or the preference-based measure (PBM) approach (e.g. EQ-5D).

RESULTS

We identified 227 CUAs with a maximum in 2009, 2010, and 2012. Most CUAs were conducted in depression, dementia, or psychosis, and came from the US or the UK, with the EQ-5D being the most frequently used instrument. The application of the direct approach was significantly associated with depression, psychosis, and model-based studies. The PBM approach was more likely to be used in recent studies, dementia, Europe, and empirical studies. Utility weights used in model-based studies were derived from only a small number of studies.

LIMITATIONS

We only searched four databases and did not evaluate the quality of the included studies.

CONCLUSIONS

Direct instruments and PBMs are used to elicit utility weights in CUAs with different frequencies regarding study type, mental disorder, and country.

Determinants of buprenorphine treatment for opioid dependence

This study assessed the social, demographic and clinical determinants of whether an opioid-dependent patient received buprenorphine versus an alternative therapy. A retrospective cohort analysis of opioid-dependent adults enrolled in Group Health Cooperative between January 1, 2006 and December 1, 2010 was performed. Increasing the number of physicians with DATA waivers in a region and living in a relatively-populated area increased the likelihood of being treated with buprenorphine, indicating that lack of access is a potential barrier. Comorbidity also appeared to be a factor in receipt of treatment, with the effect varying by diagnosis. Finally, patients with an insurance plan allowing health services to be sought from any provider, with increased cost sharing, were significantly more likely to receive buprenorphine, implying that patient demand is a factor. Programs integrating patient education, physician training, and support from addiction specialists would be likely facilitators of increasing access to this cost-effective treatment.

Surviving oppression under the rock: the intersection of New York's drug, welfare, and educational polices in the lived experiences of low-income African Americans

Drawing on standpoint and intersectionality theories, this study explores the degree to which interactions among New York State's Rockefeller Drug Laws and educational and welfare policies have contributed to the maintenance of a culture of surveillance in which the lives of impoverished African Americans are overseen and influenced by oppressive policies and governmental institutions. Qualitative secondary analysis of longitudinal ethnographic data was conducted. Findings demonstrate multiple disadvantages that impoverished African American families struggling with substance use or sale experience. These disadvantages accumulated intergenerationally, in a snowball effect, making it difficult for participants to maintain stable lives. Findings explored the tension between participants' lived experiences and the multiple ways they either assimilated or resisted their oppression. New sensitive policies informed by standpoint, intersectionality, and Afrocentric perspectives must be developed to increase the availability of meaningful employment and strengthening impoverished African American communities.

Characteristics and 9-month outcomes of discharged methadone maintenance clients

This study is a secondary data analysis of a clinical trial assessing the effectiveness of outreach case management (OCM) in linking discharged methadone patients back into treatment. The original trial assessed the effectiveness of the OCM intervention compared to a passive referral among methadone clients who needed treatment postdischarge but had not reengaged. The purpose of this study was to assess the characteristics and long-term outcomes of all clients who were discharged from methadone maintenance treatment including those who had reengaged in treatment. A total of 230 methadone clients were interviewed 3 months and then again at 9 months following discharge from treatment. Compared with participants who needed treatment but had not reengaged (NoTx: 56%), those who had successfully reenrolled in treatment (Tx; 44%) were more likely to be female, not married, and unemployed; had a longer history of sedative use; reported more psychiatric hospitalizations; and were originally enrolled in a community-based rather than a Veterans Administration program. Despite having more severe problems, the Tx group had fewer opioid-positive urines and reported less IV drug use at 9 months postdischarge compared to the NoTx group. The findings highlight the importance of rapid treatment reengagement.

Methadone maintenance and the cost and utilization of health care among individuals dependent on opioids in a commercial health plan

BACKGROUND

Few health plans provide maintenance medication for opioid dependence. This study assessed the cost of treating opioid-dependent members in a commercial health plan and the impacts of methadone maintenance on costs of care.

METHODS

Individuals with diagnoses of opioid dependence (two or more diagnoses per year) and at least 9 months of health plan eligibility each year were extracted from electronic health records for the years 2000 through 2004 (1,518 individuals and 2,523 observations across the study period-some individuals were in multiple years). Analyses examined the patterns and costs of health care for three groups of patients: (1) one or more methadone visits during the year (n=1,298; 51%); (2) no methadone visits and 0 or 1 visits in the Addiction Medicine Department (n=370; 15%); (3) no methadone visits and 2 or more visits in addiction medicine (n=855; 34%).

RESULTS

Primary care (86%), emergency department (48%) and inpatient (24%) visits were common. Mean total annual costs to the health plan were $11,200 (2004 dollars) per member per year. The health plan's costs for members receiving methadone maintenance were 50% lower ($7,163) when compared to those with two or more outpatient addiction treatment visits but no methadone ($14,157) and 62% lower than those with one or zero outpatient addiction treatment visits and no methadone treatment ($18,694).

CONCLUSIONS

Use of opioid maintenance services was associated with lower total costs of care for opioid-dependent members in a commercial health plan.

Health economic assessment: a methodological primer

This review article aims to provide an introduction to the methodology of health economic assessment of a health technology. Attention is paid to defining the fundamental concepts and terms that are relevant to health economic assessments. The article describes the methodology underlying a cost study (identification, measurement and valuation of resource use, calculation of costs), an economic evaluation (type of economic evaluation, the cost-effectiveness plane, trial- and model-based economic evaluation, discounting, sensitivity analysis, incremental analysis), and a budget impact analysis. Key references are provided for those readers who wish a more advanced understanding of health economic assessments.

Cost analysis of clinic and office-based treatment of opioid dependence: results with methadone and buprenorphine in clinically stable patients

The cost of providing and receiving treatment for opioid dependence can determine its adoption. To compare the cost of clinic-based methadone (MC, n=23), office-based methadone (MO, n=21), and office-based buprenorphine (BO, n=34) we performed an analysis of treatment and patient costs over 6 months of maintenance in patients who had previously been stabilized for at least 1 year. We performed statistical comparisons using ANOVA and chi-square tests and performed a sensitivity analysis varying cost estimates and intensity of clinical contact. The cost of providing 1 month of treatment per patient was $147 (MC), $220 (MO) and $336 (BO) (p<0.001). Mean monthly medication cost was $93 (MC), $86 (MO) and $257 (BO) (p<0.001). The cost to patients was $92 (MC), $63 (MO) and $38 (BO) (p=0.102). Sensitivity analyses, varying cost estimates and clinical contact, result in total monthly costs of $117 to $183 (MC), $149 to $279 (MO), $292 to $499 (BO). Monthly patient costs were $84 to $133 (MC), $55 to $105 (MO) and $34 to $65 (BO). We conclude that providing clinic-based methadone is least expensive. The price of buprenorphine accounts for a major portion of the difference in costs. For patients, office-based treatment may be less expensive.

Office-based maintenance treatment of opioid dependence: how does it compare with traditional approaches?

The increasing global public health burden of heroin dependence and prescription opioid dependence warrants further expansion of treatment models. The most effective intervention for opioid dependence remains maintenance with methadone, a full mu-opioid receptor agonist, or buprenorphine, a partial mu-opioid receptor agonist.A growing body of evidence supports the use of opioid receptor agonist maintenance in office-based settings. Office-based opioid treatment (OBOT) can expand treatment access in a less stigmatized environment, which enables integrated care of co-morbid conditions. The current review primarily examines OBOT in the US, although a comparison with the British and French models is provided, given that the public health impact and implementation of OBOT will likely vary between countries because of policy and logistical differences. The comparative effectiveness of maintenance treatment in office-based and traditional programme-based models of care requires further study. Clinical and practical considerations when providing treatment for opioid dependence in traditional versus office-based settings include patient selection and monitoring, health economics, management of co-morbid conditions, and access to ancillary psychosocial treatment. OBOT is not a replacement for more structured, traditional models of care, but provides an additional opportunity to help address the tremendous public health impact of opioid dependence.

A survey of Zanzibari heroin users

This paper reports on a questionnaire survey of 300 heroin users in Zanzibar town, in Tanzania. It was found that about 13% of respondents were current injectors of heroin, but that 38% of respondents reported have ‘ever injected’ heroin. Many injectors reported hiding their needles and syringes and almost half of them had shared their equipment during the past four weeks. Most of the respondents reported that they had not had sexual intercourse during the past four weeks. Of those who were sexually active most reported not having used a condom the last time they had intercourse. These findings highlight the need for a wider recognition of the extent of heroin use in East Africa as well as the urgent need to provide harm reduction and treatment services.

Economic evaluation of interventions to treat opiate dependence : a review of the evidence

Opiate dependence imposes a significant economic burden on society in terms of treatment-related costs and prevention services, other healthcare costs, the work absenteeism of patients, productivity loss arising from premature death of patients, costs associated with crime, and social welfare expenditure. The objective of this research is to review the literature on economic evaluation of treatment of opiate dependence (including detoxification, maintenance and psychosocial support).A literature review was performed on several electronic databases, including MEDLINE (Ovid), Cochrane Database of Systematic Reviews, NHS Economic Evaluation Library Database (via Cochrane Library), Web of Science, Social Science Citations Index, EMBASE and PsycINFO. A sensitive approach was used in order to maximize the number of articles retrieved; no language or publication year limitations were applied to the searches. A combination of subject heading term searches and natural word searches were used. The Drummond checklist was applied to assess the quality of economic evaluations.A total of 259 articles were considered relevant, with eight review studies identified. The treatment spectrum ranged from detoxification to maintenance treatments involving the use of agonist and/or antagonist treatments. The evidence suggests that, although the quality of economic evaluations is reasonably good, there is a dearth of knowledge about the cost effectiveness of treatments for opiate dependence. The majority of the literature reporting the results of cost-effectiveness analyses used surrogate outcome measures and adopted a narrow treatment provider perspective. Studies that have conducted cost-benefit analyses, in spite of methodological divergences, generally adopted a societal perspective and consistently demonstrated positive economic returns from opiate treatment. A paucity of research examined the extent to which psychosocial or behavioural interventions support or replace conventional pharmacological approaches. Economic evaluation provides a useful framework to assist policy makers in allocating resources across competing needs. Opiate dependence is a considerable burden on society's resources, and treatment provides a cost-beneficial solution to address these consequences. However, to better inform the decision-making process, researchers must continue to produce high-quality, methodological, comparable and scientifically credible economic evaluations.

Predictors of methadone maintenance treatment utilization in a multisite cohort of illicit opioid users (OPICAN)

Although methadone maintenance treatment (MMT) has been a primary treatment response to illicit opioid use in Canada for decades, analytical treatment data are scarce. Using data from the multisite OPICAN cohort of illicit opioid and other drug users repeatedly assessed between 2002 (baseline) and 2005 (last follow-up [FU]), we (1) longitudinally examined characteristics associated with MMT uptake between baseline and FU and (2) cross-sectionally compared drug use patterns between cohort participants in MMT (n = 133) and those not in MMT (n = 400) at the last FU through bivariate and multivariate analyses (stepwise logistic regression). Significant baseline predictors of MMT uptake emerging in the logistic regression model included injection drug, heroin, as well as alcohol use, housing status, and Quebec City as a site. Furthermore, lower prevalence levels of opioid (e.g., morphine and OxyContin) and nonopioid (e.g., cocaine and crack) drug use as well as lower frequency of heroin use days were observed among MMT users. This study highlights potential factors relevant for improved MMT uptake and illustrates possible reductions of drug use related to MMT.