Provision of Methadone Treatment in Primary Care Medical Practices: Title and subTitle BreakReview of the Scottish Experience and Implications for US Policy

The US Department of Health and Human Services is considering significant changes in policy toward the treatment of drug abuse in the United States. On July 22, 1999, the Federal Register published proposed rule changes covering narcotic drugs in maintenance and detoxification treatment of narcotic dependence.¹ These rule changes are intended, among other things, to allow physicians in private or group practice to provide opioid agonist treatment outside the traditional setting of methadone maintenance clinics.

While the effectiveness of methadone treatment for opiate addiction has been well established,² proper direction of drug abuse programs in the United States continues to be the subject of considerable debate in both the academic literature and the popular press.^{3 - 7} A recent consensus conference⁸ emphasized the need for integration of substance abuse services with primary care; however, because of current restrictive regulations on methadone prescribing, the experience in the United States of integrating methadone maintenance treatment with primary care has been limited to a few investigational studies (eg, Novick et al⁹ ). Thus, both US physicians and policymakers may have significant concerns about the implementation of the new proposed rule. These include concerns by primary care physicians regarding assuming clinical responsibility for a difficult client population, speculation that primary care physicians would not be as effective in providing this service as specialized methadone clinics, and concerns regarding the possibility of increased deaths due to methadone overdoses because of "leakage" of methadone into the illegal drug market. In addition, concern that expansion of methadone maintenance will be perceived by the voting public as "softness" on drug abusers has dampened political enthusiasm for this approach in some jurisdictions.^{7 ,10} The absence of rigorous, large-scale evaluations of the comparative safety and efficacy of traditional methadone clinics and primary care–based opioid agonist treatment programs amplifies these concerns.

In this context, review of the Scottish experience with integration of primary medical care and substance abuse treatment is useful. Over the last decade, 2 of Scotland's largest cities—Edinburgh and Glasgow—have developed effective service systems that integrate primary care, specialty care, and methadone maintenance for heroin addicts. The primary care physician is the central provider, managing health care for this medically complex population and prescribing methadone. To better understand the history and structure of these Scottish systems, we conducted a series of site visits and semistructured interviews with senior public health officials, program managers, and primary care providers in Edinburgh and Glasgow in 1996 and again in 1998. To determine program outcomes, we reviewed published literature and program reports.

A survey conducted in 1986 found the seroprevalence of injection drug users in parts of Edinburgh to be 60%, the highest then recorded in Europe. In response to this crisis and the active advocacy of a well-respected local general practitioner, the Edinburgh Health Board created the Community Drug Problem Service (CDPS).¹¹ The explicit goal of the service was changing substance abusers' habits from injecting to oral consumption, and, if injecting, away from use of shared equipment. The fundamental strategy of the CDPS is "shared care," ie, the care of the patient is shared between the specialty drug abuse service and the general practitioner. The CDPS receives referrals for treatment, performs multidisciplinary intake assessments, assigns a caseworker to the client, and links the patient with a general practitioner if the patient does not already have a relationship with one. The general practitioners are responsible for the patients' medical management, including the option of prescribing methadone. The CDPS provides consultation service, especially for difficult to manage patients, and liaison with other psychiatric and medical services.¹²

In 1995, a program was introduced to compensate participating physicians with additional reimbursement to expand the base of physicians caring for drug abusers and to improve the standard of care that they received. To this end, a comprehensive manual, "Managing Drug Users in General Practice," was distributed to every general practice in Edinburgh in December 1995.¹³ Practices were deemed eligible to join the program if they agreed to manage drug abusers according to the guidelines laid out in the manual. Despite the nominal additional sums paid to participating physicians, the number of practices participating in the pilot program expanded rapidly and, as of 1998, stood at 75 (59% of practices), with 6000 consultations per quarter, serving more than 1600 drug abusers.^{14 - 16}

In 1996, the Edinburgh Health Board reported 44 deaths due to methadone overdose.¹⁷ In response, supervised consumption of methadone has been introduced, at onset of treatment and then 2 weeks per year thereafter for all patients. Patients dually diagnosed with serious mental disorders or others judged to be high risk for poor compliance can take their medications continuously under the supervision of a pharmacist.

A 6-year evaluation found that the Edinburgh program has successfully achieved its original goals. The proportion of CDPS referrals who reported ever sharing injecting equipment fell from 85% in 1988 to 51% in 1993. In addition, the human immunodeficiency virus (HIV) seropositivity rate in CDPS referrals fell from 21% in 1988 to 8% in 1993.¹⁸

In 1992, 2 Glasgow general practitioners organized a user group for physicians prescribing methadone to combat the "chaotic" prescribing practices throughout the city. In 1994, in an effort to expand and improve drug treatment services, the Glasgow Health Board entered into a comprehensive agreement with the general practitioners. The health board recognized that services to drug abusers required efforts beyond those normally contractually agreed on between general practitioners and the health board and agreed to compensate general practitioners with an extra payment for each substance abuser enrolled in their practices if the physicians attended biannual training courses in prescribing methadone and prescribed according to guidelines developed during the negotiations.¹⁹ These guidelines are updated regularly.²⁰

As in Edinburgh, the payments did not compensate the physicians fully for the extra work involved in caring for these patients.²¹ In addition, limits were placed on the number of substance abusers to be enrolled in a given practice. General practitioners were allowed to enroll between 5 and 20 drug-abusing patients into their practices, to be seen at dedicated clinic times; patients were also to receive regular drug counseling from a drug counselor or trained nurse. These latter provisions served to prevent the overloading of practices by the number of addicts and their complex social problems.

The specialist support system in the Glasgow model, known as the Glasgow Drug Problem Service (GDPS), was developed based on the experience in Edinburgh, but with significant modifications. Rather than being staffed by psychiatric consultants, GDPS is led by a former general practitioner with extensive experience in managing substance abuse patients. The teams consist of specialist nurses working in concert with general practitioners.¹⁹

The Glasgow plan requires that, at least for the first year of treatment, all methadone (except for a Sunday dose) is consumed daily under direct supervision by pharmacists. The health board provided funds in the budget to compensate pharmacies for this service. This provision largely eliminated concerns about leakage of methadone into illicit uses and methadone-related overdoses.

By 1998, the program was serving around 2900 patients per year in methadone maintenance out of an estimated 4000 to 7000 injection drug users, of whom 80% to 90% inject heroin. As of 1999, 138 general practitioners (30% of the total general practitioners in Glasgow), along with 75% of community pharmacies, are participating in the Glasgow program. The expansion of methadone treatment has been partially credited with substantial declines in property crimes in Glasgow. A survey showed that patients receiving methadone maintenance committed an average of 8 offenses per month compared with 26 offenses per month among injection drug users not receiving methadone.²²

As measures of access, we examined the proportion of drug abusers enrolled in programs. As measures of quality, we considered retention rates, methadone doses, proportion of drug abusers receiving counseling, and methadone-related deaths. In some instances we compared these outcomes with those reported in US studies to provide a context for the reader. Outcome measures of effectiveness^{23 - 24} are best evaluated within a culture and service delivery system. Comparison of outcomes between substance abuse treatment policies in the United States and abroad are fraught with difficulties. Not only do the patterns of illicit drug use vary tremendously, even between different metropolitan areas within the United States, but the structure of medical and social services systems differ as well. Thus, comparisons are based on available, rather than strictly comparable, data.

Most recent estimates place the proportion of injection drug users receiving oral substitution at 60% to 80% of the total injection drug users in Edinburgh. Estimates from 1998-1999 in Glasgow indicate that between 41% and 73% of injection drug users in the Glasgow metropolitan area receive methadone maintenance. In contrast, the United States has an estimated 810,000 heroin addicts and 115,000 (14%) individuals in methadone maintenance programs.²⁵ Lewis²⁶ points out that 85% of addicts in the United States have no access to legal methadone.

Peters and Reid²⁷ studied a 1990-1991 cohort of patients treated with methadone maintenance in Edinburgh and found a retention rate of 39% at 12 months. A 1994-1996 cohort in Glasgow demonstrated a 60% retention rate over 1 year in methadone maintenance.¹⁹ The retention rate for the Glasgow program is consistent with findings by MacGowan et al²⁸ and Novick et al⁹ who report US programs that integrate primary care and substance abuse treatment have higher retention rates than those that provide substance abuse treatment alone. Note that the average dose of methadone prescribed during 1990-1991 in Edinburgh (40 mg) was considerably lower than that used in Glasgow during 1994-1996 (54 mg) and may be responsible in part for the lower retention rate observed at this time.

Adequate methadone dose levels are increasingly recognized as key to the effectiveness of this treatment modality.^{29 - 30} By 1998, the Scottish programs were administering methadone at effective dose levels. As mentioned above, the average dose of methadone used in the early years of the CDPS program in Edinburgh was 40 mg, less than the dose usually considered therapeutic.³¹ Since the publication of a manual for general practitioners and the institution of a support team to provide ongoing education to them, the average dose of methadone has increased to 61 mg in 1998.^{15 - 16}

Another concern with regard to primary care physicians treating substance abusers in private offices is that referral to counseling services will diminish. Available evidence suggests that counseling services are advocated for substance abusers by experts in both the United States and Scotland, but that provision of such services is inconsistent in both countries. Frequency of patient visits to drug counselors in Edinburgh varies widely from weekly to 3 times per month, without fixed policies.²⁷ Counseling support to patients receiving methadone maintenance in Glasgow is provided by 15 community drug projects. Some practices provide additional support through weekly drug clinics or practice nurses. The content, format, and intensity of counseling vary widely between practices.¹⁹ In her review of factors related to retention and treatment outcomes in methadone maintenance programs in the United States, Etheridge³² noted that the counseling services available to patients in the 1990s have dropped dramatically from those available in the 1970s.

The risk that methadone will enter the illicit drug market, contributing to an increase in methadone deaths, has been a major concern for the Scottish programs as well as in the United States. To address the issue of safety, we examined the electronic databases tabulating drug abuse deaths in the United States for 1996 and Scotland for 1997 and reviewed data supplied by the Glasgow Health Board for 1998. The geographic distribution of methadone deaths in Scotland suggests that supervised consumption of methadone can restrict leakage of methadone into the streets. Glasgow, with a much larger addict population, had a comparatively lower number of methadone-related deaths than Edinburgh where methadone consumption was not as extensively supervised. The General Register Office for Scotland³³ reported 263 drug-related deaths for 1997. Glasgow accounted for 69 of drug-related deaths, while Edinburgh had 46. Methadone was detected in 79 (30%) of drug-related deaths in Scotland. However, the distribution of deaths in which methadone and heroin were detected varied strikingly. In Glasgow, 17 individuals died with methadone detected and 44 died with opiates detected (note that multiple drugs were detected in some individuals). However, in Edinburgh, 30 individuals died with methadone (and benzodiazepines) detected but only 3 with heroin. The difference between the proportions of deaths related to methadone in Glasgow and Edinburgh is significant at the P<.0001 level (z = 4.14, test for 2 proportions). Table 1 displays drug deaths from Glasgow and Edinburgh for 1997 and 1998. At particular risk for death due to methadone overdose were individuals recently released from prison,³⁴ presumably due to decreased opiate tolerance.

Concern regarding methadone-related deaths has often been cited by proponents of a restrictive policy toward methadone in the United States. Although the Scottish experience indicates that methadone can be abused, methadone is less likely to be abused than other opiates because it does not produce significant euphoria and actually blocks the euphoric effect of injected opiates.³⁵ The risk of death to heroin addicts from heroin is considerably greater than the risk of death from a methadone overdose. The Drug Abuse Warning Network reported 3979 deaths in selected US metropolitan areas for 1996 caused by heroin or morphine, as opposed to 552 caused by methadone.³⁶ Of the 552 methadone deaths, only 19 (3%) were cases in which methadone was the only drug substance directly responsible for death. Desmond and Maddux³⁷ compared the mortality rates of patients receiving methadone with those of patients discharged from methadone maintenance. Results of the 7 studies included in their review demonstrate that the relative mortality risk for patients after discharge from methadone maintenance is 2.3 to 4.2 times higher than their risk while receiving methadone maintenance.

In a previous article on Medicaid use in Maryland,³⁸ we demonstrated that substance abuse was a frequent comorbid condition for adult patients, not in long-term care, whose annual Medicaid expenditures fell into the top 10% for all Medicaid enrollees. As both the US^{9 ,26 ,39} and Scottish experiences indicate, advantages of providing methadone maintenance in primary care physicians' offices include: (1) distributed geographic access, (2) the avoidance of the stigma associated with attending methadone clinics, and (3) an increased ability to treat comorbidity in this high-risk population. Current US primary care guidelines emphasize referral of patients to methadone clinics,⁴⁰ and only a few methadone clinics offer primary care services on-site. Primary care physicians can adequately provide methadone maintenance⁹ and detoxification⁴¹ in ambulatory settings. There is general agreement that a larger role for primary care physicians in the treatment of substance abuse would be desirable.⁴² What policies would be necessary to motivate a significant number of primary care physicians to play a larger role in drug treatment?

Several conclusions can be drawn from the Scottish experience. First, in both Edinburgh and Glasgow, the leadership for expansion of methadone services into the primary care physicians' offices was led by physicians responding to the medical needs they perceived in their communities. Second, while financial incentives were perceived as helpful by the Scottish general practitioners, they were not their sole concern. Although some observers may view physicians in the United States as more financially motivated than their counterparts in the United Kingdom, recent work on primary care physician behavior in response to financial incentives⁴³ suggests that other factors need to be considered in addition to compensation to explain physicians' practice behaviors.⁴⁴ Third, professional as well as financial support for primary care physicians engaging in the care of substance abusers is crucial. The Edinburgh CDPS and the Glasgow GDPS work closely with their general practitioners to address provider concerns and improve patient care.

Even in the United Kingdom, general practitioners' attitudes toward drug abusers have remained overwhelmingly negative, with comparatively few practitioners evincing an interest in undertaking their care.^{45 - 46} The drug problem services in Edinburgh and Glasgow undertook significant outreach and educational efforts toward the primary care physicians. Using a "shared care" model, both central drug problem services provided consultation for difficult patients; facilitator teams that meet with primary care physicians in their offices to review practices and consult on problems; and drug counselors or visiting public health nurses to assist the general practitioners. Thus, physicians practicing in the community have substantial support available to assist them in the care of patients receiving methadone maintenance, and this support has fostered physician participation. As a result, in contrast to the negative attitudes expressed by general practitioners throughout the United Kingdom as a whole, the number of practices in these cities providing methadone treatment has been continually growing. A survey in Edinburgh^{15 - 16} demonstrated that 60% of general practitioners participating in methadone maintenance feel that their practice has improved as a result of the educational and outreach activities of the CDPS specialist services.

The methadone programs in Edinburgh and Glasgow are widely regarded as models for the National Health Service, and the British government has issued a series of white papers and program guidelines^{47 - 49} instructing local health authorities to establish shared care for problem drug users. However, as of 1998, only 30 of 120 health authorities had made an initial assessment of their drug problem, and only 26 had instituted a shared care model.⁵⁰ In most areas of the country, general practitioners feel that their support for treating drug abusers is inadequate.⁵¹

Our review highlights the importance of physician leadership in Scotland in gaining public acceptance of methadone maintenance and in developing the specialist services necessary to assist primary care physicians in prescribing methadone and caring for the patients receiving it. Without physician leadership, public officials are unlikely to maintain the public support required for such programs. One senior official in Scotland, speaking in confidence, noted that maintaining public support for effective prevention and treatment policies for substance abuse was the most difficult challenge of his career. A particular difficulty facing public officials is the need to coordinate services across traditional agency boundaries to provide effective care.⁵² In both Edinburgh and Glasgow, officials report that neither the CDPS nor the GDPS would have been possible without the active leadership of 1 or 2 well-respected general practitioners who had the support of key public health officials. Physician leadership on this issue is equally vital in the United States. A recent review of state Medicaid programs finds that in 25 states Medicaid does not cover methadone treatment.⁵³ Blendon and Young⁵⁴ report that, based on an analysis of 47 national surveys, weak support exists for increasing funding for drug treatment, and that needle exchange programs are supported by a bare majority of Americans, but only when they are told that the American Medical Association supports these programs.

Despite cultural differences (including health system culture), we can draw important lessons from the Scottish experience. The positive outcomes in Edinburgh and Glasgow provide useful guidance for implementation of the federal government's proposed changes, most notably:

1. Prescription of methadone by primary care physicians can safely increase the availability of an important treatment modality, and at the same time improve health care for this difficult-to-reach population. Expansion of access to methadone treatment has important public health consequences, eg, decreased HIV seroprevalence and drug-related crime.

2. Physician education and financial incentives improve prescribing practice.

3. Supervised consumption of methadone reduces the risk of methadone-related deaths.

4. Physician support is a critical ingredient in the development and maintenance of effective drug treatment policies.