Expanding treatment capacity for opioid dependence with office-based treatment with buprenorphine: National surveys of physicians

Journal of Substance Abuse Treatment 39 (2010) 96 – 104

Regular article

Expanding treatment capacity for opioid dependence with office-based treatment with buprenorphine: National surveys of physicians Cynthia L. Arfken, (Ph.D.) a,⁎, Chris-Ellyn Johanson, (Ph.D.) a,b , Salvatore di Menza, (M.S.) b , Charles Roberts Schuster, (Ph.D.) a,b a

Department of Psychiatry and Behavioral Neurosciences, Wayne State University, Detroit, MI 48207, USA b CRS Associates, LLC, Chicago, IL 60616, USA Received 13 January 2010; received in revised form 19 April 2010; accepted 5 May 2010

Abstract Office-based treatment of opioid dependence with buprenorphine has the potential to expand treatment capacity in the United States. However, nationally, little is known about the number, characteristics, and experiences of physicians certified to prescribe buprenorphine. Moreover, little is known about the impact of easing federal regulations on the number of patients a physician is allowed to treat concurrently. To address these questions, surveys of national samples of physicians certified to prescribe buprenorphine (2004–2008) were analyzed (N = 6,892). There has been a continual increase in the number of physicians certified to prescribe buprenorphine, increase in the mean number of patients treated by physicians, and decrease in patients turned away, coinciding temporally with easing of federal regulations. In addition, most physicians prescribed buprenorphine outside of traditional treatment settings. The U.S. experiment in expanding Schedule III-V medications for opioid dependence to physicians outside of formal substance abuse treatment facilities appears to have resulted in expanded capacity. © 2010 Elsevier Inc. All rights reserved. Keywords: Buprenorphine; Suboxone; Subutex; Physicians; Survey

1. Introduction Opioid dependence is a major public health problem in the United States, both due to the use of heroin (SAMHSA, 2007) and to an increasing number of individuals developing dependence on prescription opioids (SAMHSA, 2006). Expanding treatment services to meet their needs is a challenge. Until 2002, medications for opioid dependence were limited to the two opioid agonists, methadone and LAAM (withdrawn from market in 2003), or the antagonist naltrexone. Prescribing methadone is restricted to hospitals and federal- and state-approved opioid replacement sub⁎ Corresponding author. Department of Psychiatry and Behavioral Neurosciences, Wayne State University, Detroit, MI 48207, USA. Tel.: +1 313 993 3490; fax: +1 313 577 5062. E-mail address: [email protected] (C.L. Arfken). 0740-5472/$ – see front matter © 2010 Elsevier Inc. All rights reserved. doi:10.1016/j.jsat.2010.05.004

stance abuse treatment programs (i.e., methadone maintenance programs). Physicians can prescribe naltrexone, but patients must be opioid-free for several days prior to initiating its use. Thus, for physicians confronted with patients with opioid dependence, the options prior to 2002 were the antagonist naltrexone or the agonist medication methadone provided under strict regulations and within limited facilities. To expand treatment options for opioid dependence and other substance use disorders, the National Institute on Drug Abuse (NIDA) initiated and continues to maintain a medication development program. As part of that program, NIDA collaborated with Reckitt Benckiser Pharmaceutical, Inc., to support safety and efficacy studies of sublingually administered buprenorphine, a partial mu-opioid receptor agonist. Evidence from laboratory-based preclinical and clinical studies suggests that buprenorphine has a better safety profile and lower abuse liability than methadone

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(Mello & Mendelson, 1985; Walsh & Eissenberg, 2003). Importantly, clinical trials indicated that buprenorphine was efficacious and effective for the treatment of opioid dependence (Fiellin et al., 2006; Fudula et al., 2003; Johnson, Jaffe, & Fudala, 1992; Ling et al., 1998). In response to early reports of nonmedical use of buprenorphine in other countries (e.g., Harper, 1983; Lavelle, Hammersley, Forsyth, & Bain, 1991; O'Connor, Maloney, Travers, & Campbell, 1988; Singh, Mattoo, Malhotra, & Varma, 1992), a sublingual formulation of buprenorphine and the opioid antagonist naloxone, designed to discourage parenteral abuse, was developed. The Food and Drug Administration (FDA) approved the buprenorphine/naloxone ormulation (Suboxone) as well as a mono preparation (Subutex) of buprenorphine for the treatment of opioid dependence in 2002 and placed both formulations in Schedule III under the Controlled Substances Act of 1970 (CSA). Although the introduction of buprenorphine expanded the availability of medications for the treatment of opioid dependence, there also needed to be an expansion of treatment resources beyond the existing substance abuse treatment programs. The U.S. Drug Addiction Treatment Act of 2000 (DATA) accomplished this expansion by allowing medications in Schedules III, IV, or V that were approved by the FDA for the treatment of opioid dependence to be prescribed by physicians in office-based settings. Thus, when FDA approved the monoformulation of buprenorphine and buprenorphine/naloxone for the treatment of opioid dependence and placed both formulations in Schedule III, it became possible for physicians to prescribe these medications in their offices for detoxification or long-term maintenance (McNicholas, 2004). These new prescribing privileges were contingent on physicians obtaining certification from the U.S. government. To obtain this certification, physicians had to verify that they were already certified addiction specialists, had participated as principal investigators in clinical trials with buprenorphine for the treatment of opioid dependence, or had received 8 hours of approved training on the appropriate use of buprenorphine for the treatment of opioid dependence. Along with restrictions on acceptable training, there were restrictions on the number of patients that could be treated with a Schedule III, IV, or V opioid (i.e., buprenorphine) concurrently. Initially, individual physicians and group practices were not allowed to concurrently treat more than 30 patients. The restriction on group practices was then replaced in 2006 with the limitation of 30 patients per physician, regardless of the type of practice. A survey of physicians certified to prescribe buprenorphine in 2005 confirmed that addiction specialists were more likely to be certified and to prescribe the medication compared to nonaddiction psychiatrists (Thomas et al., 2008). As documented by Mark et al. (2009), the volume and physician specialty distribution have expanded greatly since early introduction, suggesting expanded capacity.

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The regulations were again modified in January 2007 to allow up to 100 patients per physician after the physician had a year of experience prescribing buprenorphine under the 30-patient limit and registered intent to treat more than 30 patients. This policy change may have increased the number of patients receiving treatment, but to date, no research to our knowledge has examined it. All physicians who were certified to prescribe buprenorphine are identified on a computerized list maintained by the federal Drug Enforcement Administration (DEA). In addition, the DEA, which could audit physician records unannounced, maintains oversight of certified physicians under established regulatory authority of the CSA. Physicians also had the option of having their names and contact information listed on a publicly available physician locator Web site (http://buprenorphine.samhsa.gov/bwns_locator/ aboutphysician.htm) maintained by the federal Center for Substance Abuse Treatment (CSAT). By policy, this physician locator Web site was designed to allow potential patients free access to quickly search for physicians certified to prescribe buprenorphine. In contrast, the DEA list is available only for a fee. As a result, there may be differences in the characteristics and practices of physicians on the CSAT Locator List compared to those not on the list, which may in turn impact the patient seeking treatment. However, no one to our knowledge has ever compared the characteristics or practices of physicians on the CSAT Locator List to those not on the list. The pharmacological treatment of opioid dependence in an office setting represents a new practice paradigm for U.S. physicians (Fiellin & O'Connor, 2002). However, physicians may be reluctant to treat opioid-dependent patients in their offices for a variety of reasons, such as concerns about the impact of their presence on other patients, potential diversion/abuse of the medication, or concerns about the medication's safety. These concerns might be more prominent in physicians who chose not to be on the Public Locator List. In addition, certified physicians who prescribe and those who do not may differ in their perspective on these barriers. In fact, several studies have documented substantial barriers to prescribing buprenorphine as perceived by physicians (Barry et al., 2008; Gunderson et al., 2006; Netherland et al., 2009; Thomas et al., 2008; Walley, Alperen, Cheng, Botticelli, et al., 2008), but none of these studies have been based upon a national sample. Continuing education beyond the initial training through conferences, articles, or formal mentoring is a strategy to reduce any perceived concerns and promote good practices (Thomas et al., 2008). However, it is unclear if physicians continue to utilize these resources after initial training. Furthermore, continued education concerning the use of buprenorphine for the treatment of opioid dependence may differ between physicians on the CSAT Locator List and those not on the list. The objective of this report is to describe the abovementioned policies' impact on the growth in the number of

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physicians certified to prescribe buprenorphine, as well as other indicators of growth in access to treatment, the nature of physician practices, how the medication is being used, numbers of patients treated, limitations in access to treatment, and barriers to use. The analysis builds upon a U.S. government report of the first year experience with buprenorphine (Stanton et al., 2005). 2. Methods 2.1. Sample As a requirement to FDA approval, the manufacturer agreed to a Phase IV commitment to a risk management program that included postmarketing surveillance. One aspect of the surveillance system was a quarterly mailed survey of randomly selected certified physicians. The random samples were drawn initially from the CSAT Locator List of certified physicians, starting in the last quarter of 2003. In 2006, the sample was drawn from the complete DEA list of certified physicians as well. This survey was funded by the manufacturer, but the analyses and interpretations of outcomes were conducted independently. For the surveys, nonoverlapping separate random samples were drawn from each of the two lists: the CSAT Locator List and the DEA list (Table 1). As shown in Table 1, participation rates were consistently higher for the physicians on the CSAT Locator List and stable across years until 2008. Because the samples are drawn randomly each quarter, the samples over time may include physicians who have responded in prior quarters. During 2007, a large proportion of the surveys for one quarter were lost in mailing, reducing the sample size for that year. Each quarter, surveys were mailed in a packet containing a cover letter, the survey, and a postage-paid business reply envelope. The physician was asked to return the survey by a specified date, approximately 40 days later. A reminder postcard was also sent to the physician before the deadline. Surveys returned by the specified date were electronically scanned and entered into a database. Physicians were reimbursed for their participation. The

Wayne State University Institutional Review Board approved all procedures. 2.2. Measures During the period 2004 through 2008, the survey had 25–35 questions. Most questions had a multiple-choice format to minimize time burden and facilitate scanning for data entry. This report will focus on questions assessing access to treatment, patient load, characteristics of the physicians, practice setting, prescribing history and practices, and perceived barriers to its use. Questions added to the survey in the second quarter of 2008 included number of patients receiving specific dosages and participation in educational activities. In the survey, the medications were described generically as “buprenorphine,” although for some inquiries, the trade names for the monoformulation (Subutex) and the buprenorphine/naloxone formulation (Suboxone) were used. For certification in addiction, physicians were asked separately about three different certifications: American Board of Medical Specialties (in Addiction), American Society of Addiction Medicine, and American Osteopathic Association (in Addiction). A physician with a certification from at least one of the three organizations was considered to be certified in addiction. Specialty was determined by physicians choosing one or more responses from a list of 14 medical specialties (including Addictions and Other). Because of the number of possible specialties, analysis was restricted to the five most commonly reported specialties. For barriers to prescribe buprenorphine, the physicians were given a list of 14 prespecified and one “other” limitation for which they were asked to mark the three they considered most important. To reduce the number of comparisons, the barriers were categorized a priori as medication concerns (limited effectiveness, difficult to titrate dosage, adverse events, medical complications); patient concerns (low acceptance by patients, diversion risk); procedural concerns (offering counseling, availability of pharmacies that carry buprenorphine, record-keeping requirement, DEA involvement); and financial concerns (high cost, third-party reimbursement). The barrier of federal limits on number of patients treated concurrently was treated as a separate barrier. 2.3. Data analysis

Table 1 Surveys mailed and participation rates by list and year Variables

2004

Mailed surveys Locator List 1,783 Not on list – Participation rate (%) Locator List 43 Not on list – a

2005

2006 a

2007

2008

2,778 –

2,530 1,766

1,681 2,000

2,931 4,009

44 –

40 34

37 35

29 24

In 2006, the names of physicians not on the CSAT Locator List were obtained after the first quarter mailing. In 2007, most of the surveys were lost in the mail during one quarter, so this quarter was eliminated from the analysis.

The 6,892 completed physician surveys from 2004 to 2008 were used to determine the mean number of patients treated with the monoformulation of buprenorphine and buprenorphine/naloxone and the percentage of physicians who identified the federal patient limit as a barrier over time. For analysis on characteristics of physicians and their practices, the sample was restricted to surveys completed in 2008 (n = 1,793) as the intent is to describe the current situation rather than change over time. For questions that were only added in the last three quarters of 2008, the sample size was 1,416.

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Fig. 1. Number of physicians on the CSAT Locator List (public list) and not on the public list, by year. All physicians on these lists are certified to prescribe buprenorphine in an office-based setting. The number of physicians on the DEA list but not the public list prior to 2006 is unknown.

Changes over time were tested using analysis of variance with year of survey being the independent variable. Consistent with the objectives of the analysis, the focus was on describing the characteristics of physicians and their practice using descriptive statistics of means and proportions. For formal testing of differences by listing, bivariate analysis using chi-square, t tests, and analysis of variance were used. No corrections for multiple comparisons were used. For several of the analyses, as noted in the tables, only physicians who were currently treating at least one patient were included.

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phine to at least one patient in the last 90 days ranged between 80% and 87% from 2004 through 2008. In contrast, the percentage for physicians not on the Locator List who reported prescribing in the last 90 days ranged from 65% to 67% during the years 2006 to 2008. The percentage of physicians with current patients was 76% in 2004 for those on the Locator List, increasing to 86% in 2008. For the physicians not on the list, the percentage with a current patient remained relatively constant from 2006 to 2008 and in 2008 was 63%. For those physicians with at least one patient currently being treated with buprenorphine, there were statistically significant changes over time in the mean number of patients currently being treated with the buprenorphine/naloxone for both those physicians on the Locator List and those who were not (Fig. 2). However, there was no change in the mean number of patients currently being treated with the monoformulation. As shown in Fig. 2, the mean number of patients being treated with buprenorphine/naloxone in 2007 was 27.3 and 15.8, respectively, for those on the CSAT Locator List and not on the public list compared to 18.4 and 12.9, respectively, in 2006, coinciding with the increase in number of patients individual physicians were allowed to treat that began in January 2007. In 2008, the mean number of patients being treated with either product was 39 for those on the Locator List and 25.9 for those not on the list. If 86.4% of the 6,593 physicians on the Locator List treat an average of 39 patients and 62.5% of the 9,069 physicians not on the list treat an average of 25.9 patients, the total number of patients served can be estimated as 368,962 or 57% of potential capacity.

3. Results 3.1. Growth in physicians qualified to prescribe buprenorphine In 2004, the number of physicians on the CSAT Locator List was 2,518 (Fig. 1). This number increased to 6,593 by the end of 2008. When the information from the DEA became available to the investigators in 2006, the number of physicians who had chosen not to be included on the CSAT Locator List (n = 4,302) was approximately the same as the number on the CSAT Locator List (n = 4,516). However, over the next 2 years, the number of physicians certified to use buprenorphine but not wanting to be included on the CSAT Locator List increased so that by the end of 2008, it was 9,069 or 38% higher than the number of physicians on CSAT Locator List (n = 6,593). Of this combined total of 15,662 physicians, 13,095 (84%) were limited to 30 patients, whereas 2,567 were authorized to treat up to 100 patients. Thus, the total patient capacity nationwide at the end of 2008 was 649,550. 3.2. Patient loads and characteristics of physician practices The percentage of certified physicians on the CSAT Locator List who reported they had prescribed buprenor-

Fig. 2. Of the physicians who are currently prescribing buprenorphine/ naloxone (circles) or monoformulation of buprenorphine (squares), mean number of patients currently being treated across years for those physicians on the CSAT Locator List (public list; filled symbols ⁎) and those not on the list (open symbols). The arrow indicates when the federal limit was increased from 30 to 100 (see text). There were significant changes in numbers currently being treated over time for buprenorphine/ naloxone [F(4, 3471) = 13.8, p b .001, for public list and F(92, 1,362) = 9.5, p b .001, for the other list] but not for the monoformulation of buprenorphine. The first quarter of 2004 was not included in the analysis because the specific formulation was not specified in the question.

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Table 2 Characteristics of physicians certified to prescribe buprenorphine, 2008 Characteristics

Locator List (n = 859)

Not on Locator List (n = 934)

p

Certificate in addictions Specialty in addictions Specialty, can be more than one Psychiatry Family medicine Internal medicine Pain management Practice setting Solo practice Single specialty group Hospital owned practice Solo practice, shared space Multispecialty practice Staff model HMO Other type of practice No. of years prescribing buprenorphine Never b1 year 1–2 years 3–4 years N4 years Missing Buprenorphine-related educational activities, past 90 days a Any of the below specific activities Continuing Medical Education (CME) activity Conference where buprenorphine was discussed Read buprenorphine article Consulted with a mentor Other unspecified activity

38.1% 28.6%

26.7% 16.5%

b.001 b.001

40.3% 26.1% 16.2% 11.0%

41.2% 26.1% 15.5% 8.9%

.70 .99 .70 .13 b.001

41.6% 13.3% 14.0% 8.8% 7.8% 1.0% 13.4%

25.8% 19.8% 17.2% 7.7% 8.3% 1.0% 20.2%

7.2% 22.6% 27.3% 25.3% 17.6% 2.3%

24.2% 19.0% 27.6% 20.5% 8.7% 2.4%

85.2% 11.3% 23.3% 67.0% 17.0% 29.0%

76.2% 8.2% 15.8% 57.6% 12.8% 22.4%

a

b.001

b.001 .049 b.001 b.001 .025 .005

Because this question for only asked in the last three quarters of the year, the sample size for the Locator List is 681 for the Locator List and 735 for the other list.

Table 2 summarizes characteristics of the physicians responding to the survey during 2008 (n = 1,793). Only about a third had a certification as an addiction specialist, but the percentage was significantly higher for the physicians on the CSAT Locator List compared to those not on this list (p b .001). Fewer physicians claimed to be an addiction specialist that had a certification, and again, the percentage was lower for those not on the CSAT Locator List (p b .001). Psychiatry was the most commonly selected specialty, followed by family medicine, internal medicine, and pain management with no difference in prevalence of individual specialties by list. The practice arrangement for physicians on the CSAT Locator List differed from physicians not on the list (p b .001), with a higher percentage of physicians on the CSAT Locator List in solo practice (41.6%) compared to 25.8% of the physicians not on the list. There were statistically significant differences in how long the physicians on the two lists had been prescribing buprenorphine (p b .001), with more physicians on the CSAT Locator List having prescribed for more than 3 years. Furthermore, 24% of those not on the CSAT Locator List had never prescribed buprenorphine, whereas only 7% of those on the CSAT Locator List responded that they had never treated a patient with buprenorphine. These percentages are comparable to the percentages of physicians who

responded that they had not treated a patient in the last 90 days in 2008 (13% on CSAT Locator List and 35% not on the list), suggesting that once physicians began prescribing buprenorphine, they continued to do so. The physicians on the CSAT Locator List were also more likely to participate in an education activity involving buprenorphine in the past 90 days than physicians not on the list (p b .001). However, most physicians not on the list had been actively involved in such activities (76.2%). 3.3. Treatment practices, 2008 Table 3 presents treatment practices for physicians who reported currently treating at least one patient with either formulation of buprenorphine during 2008 (n = 1,326). The physicians in both groups were more likely to prescribe buprenorphine/naloxone than the monoformulation. Overall, regardless of list, 94% of the patients were currently being prescribed buprenorphine/naloxone. Physicians who treated at least one patient with buprenorphine/naloxone (n = 727 and n = 570, respectively, for the two lists) reported currently prescribing between 2 and 16 mg to about 78% of their patients on the formulation with only a minor difference across lists. Within practices, 72% of patients were being maintained on buprenorphine, and again, there were no listrelated differences.

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Table 3 Treatment practices of physicians currently treating at least one patient with buprenorphine, 2008 Characteristics Physician has at least one patient on Buprenorphine/Naloxone Monoformulation Of those on buprenorphine/naloxone, dosage a, b b 2 mg 2–8 mg 10–16 mg 18–24 mg 26–32 mg N32 mg Percentage of patients on maintenance Hours of counseling per month for typical patient c None 1–3 hours 4–6 hours 7–9 hours 10 hours or more Missing Percentage of patients treated in Opiate Treatment Program Percentage of patients treated in other substance abuse treatment facility Percentage of patient load new to treatment d

Locator list (n = 742)

Not on public list (n = 584)

p

98.0% 37.2%

97.6% 30.3%

.64 .009

4.0% 31.6% 41.7% 17.2% 4.9% 0.7% 72.0%

3.3% 37.1% 39.0% 15.6% 4.6% 0.3% 72.7%

.44 .02 .21 .31 .68 .19 .67 .15

3.5% 50.5% 24.0% 10.6% 11.4% n = 97 26.1% 13.2% 32.7%

6.0% 48.0% 28.0% 9.0% 9.0% n = 84 20.3% 13.4% 32.6%

.004 .60 .93

a

Because this question was only asked in the last three quarters of the year and 2% and 2.4% of physicians from each of the lists did not have at least one patient on buprenorphine/naloxone and some did not answer the questions, these percentages are based on sample sizes of 554 for those on the Locator List and 418 for those not on the list. b This question was analyzed using a two-way analysis of variance, which yielded a p value of .04 for the interaction. Post hoc t tests were conducted to determine the source of the difference, the results of which are shown in the table. c Because this question was only asked in the last three quarters of the year, the sample size for the Locator List is 594 for the Locator List and 457 for the other list. d Because this question was only asked in the last three quarters of the year and several of the physicians failed to answer the question, the sample size for the Locator List is 494 for the Locator List and 385 for the other list.

About half of physicians in both groups reported that their “typical” patients received 1–3 hours of counseling each month, and another 24% to 28% of physicians said their “typical” patients received between 4 and 6 hours of counseling. More than 90% of physicians reported that their “typical” patient received at least 1 hour of counseling per month. Most patients within a physician's practice in both groups were not seen in an opioid maintenance program or other substance abuse treatment facility, that is, most patients were seen in a physician's office (see also Table 2). In addition, the percentage of their buprenorphine patients who the physicians believed were completely new to treatment was approximately 33% for both lists (Table 3). 3.4. Barriers to prescribing buprenorphine Physicians were asked to indicate from a list of 14 the 3 most serious limitations they perceived in the use of buprenorphine for treating opioid dependence. For both lists, financial concerns were selected by a greater percentage of physicians than any of the other barriers (71.8% on the CSAT Locator List and 59.3% not on the list). When analysis was restricted to those currently treating a patient, the percentages increased to 74.1% and 65.1%, respectively.

The physicians not on the CSAT Locator List endorsed more frequently than those on the CSAT Locator List that diversion was a barrier (26.3% vs. 18.7%). Fewer physicians saw barriers related to the medications themselves (17.2% of those on the CSAT Locator List vs. 21.7% not on the list). The percentage of physicians not on the CSAT Locator List who endorsed medication concerns fell to 18.2% among those currently treating a patient with buprenorphine. Important from a policy perspective, 14% of physicians on the CSAT Locator List and 10% of those not on the list thought that the federal restriction on the number of patients was a barrier in 2008. However, Fig. 3 shows the perception of this barrier has changed over time. Although a higher percentage of physicians on the CSAT Locator List compared to those not on the list have reported the federal regulation as a limitation, the percentage dropped substantially in 2007 for both groups of physicians. This drop coincided with the change in the regulation, which increased the limit on the number of current patients from 30 to 100. Despite any concern, most physicians never turned away any patients because of the federal limits from 2005 to 2008 (range = 70.2%–95.3%). Nevertheless, the percentage of physicians who had not turned away any patient increased for both lists after the change in the federal regulations (from 70.2% to 89.2% in 2007 and 86.8% in 2008 for those on the

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Fig. 3. Percentage of physicians who believed that the federal limit on number of patients was a limitation for prescribing buprenorphine for maintenance therapy across years for those physicians on the CSAT Locator List (public list) and those not on the list. The arrow indicates when the federal limit was increased from 30 to 100 (see text).

Locator List and from 86.3% to 95.% in 2007 and 92.5% in 2008 for those not on the Locator List). 4. Discussion One of the major purposes of DATA was to expand treatment capacity and access for opioid-dependent individuals by allowing the establishment of office-based treatment using Schedule III-IV medications that were approved for this indication. To date, the only medications that meet the criterion are the monoformulation buprenorphine and buprenorphine/naloxone. The results of the national surveys add to the evidence that treatment capacity has been greatly expanded (Stanton et al., 2005). First, the number of physicians who have sought permission to use the buprenorphine products to treat opioid dependence increased to 15,662 physicians by the end of 2008. Furthermore, only a small percentage of those who had certification to treat opioid-dependent individuals and responded to the survey reported never using the buprenorphine products to treat patients for opioid dependence. There are also indicators that once a physician begins treating this population, he or she continued to do so. Although many certified physicians are also certified as addiction specialists or psychiatrists, a sizeable number of the physicians are in family or internal medicine, specialties that do not normally treat the opioiddependent population. This growth in prescribing buprenorphine by different specialties reflects the findings based upon prescription data described by Marks et al. (2009). Further, most of their patients are treated in the physician's office, not in specialty substance abuse clinics, and physicians estimate that 33% of their patients are completely new to treatment. This new patient population may be individuals who have

avoided substance abuse treatment programs because of stigma or strict regulations and find going to a private physician's office to be less restrictive and similar to treatment of other chronic medical conditions. Our findings based upon physicians' responses, however, cannot address patients' motivations. Although there are many indicators that treatment capacity has been increased, there is still the need to treat more patients. The challenge is to determine strategies that will result in more patients seeking treatment and more physicians prescribing buprenorphine, particularly given the increase in prescription opioid abuse (SAMHSA, 2006). As outlined by previous researchers (Barry et al., 2008; Gunderson et al., 2006; Netherland et al., 2009; Thomas et al., 2008; Walley, Alperen, Cheng, Botticelli, et al., 2008) and replicated by our survey, there are substantial barriers for physicians in prescribing buprenorphine. Research on diffusion theory (Rogers, 2003) clearly shows that there is a time element from a few early adopters prescribing to later when more physicians prescribe buprenophine. Part of this delay for buprenorphine may be reflected in the increasing number and percentage of physicians who choose not to be listed on the CSAT Locator List and that these physicians are less likely to prescribe the medication. If this trend of physicians not being listed on the Public Locator List continues, additional mechanisms for patients to locate prescribers may be needed. Fortunately, there is no evidence that physicians are turning away patients in any large numbers, and even the few who are turned away may be referred to other physicians. A related concern is to address wait-lists for methadone maintenance treatment programs. It is unknown if individuals awaiting treatment are unaware of office-based treatment, prefer methadone, or if there is no additional capacity to treat patients in office-based practices in a particular region. This is clearly an area that needs more research. It is probably wiser to encourage additional physicians to treat this population rather than raising the federal limit, as treating more than 100 patients concurrently for opioid dependence could result in a decrease in the quality of care. It is also quite possible that the failure to seek treatment is related to the cost of this treatment for those without access to a third-party payer. In fact, many physicians (60% on the Locator List and 48% not on the list) endorsed high cost as a barrier to treatment. One of the concerns about DATA 2000 was that physicians without specific training in the addictions would not be competent to treat opioid-dependent individuals and would perhaps be tempted to just hand out medication as a means of generating revenue (“prescription docs”). However, the results of this national survey indicate that most physicians responding to the survey are engaging in good practices, although we cannot comment on physicians who did not respond to the survey. Of the responding physicians, most patients receive several hours of counseling each month, and the dose range for buprenorphine prescribed

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is well within that recommended. Furthermore, most physicians continue to seek additional education in the appropriate use of buprenorphine, and hopefully, other aspects of good treatment practices will be learned through these educational initiatives. Despite the enormous number of physicians who have obtained certification to treat patients in their offices, these physicians do perceive barriers to prescribing buprenorphine. The primary barrier is financial, with many physicians endorsing concern about the high cost of the medications and difficulty obtaining reimbursement for services. Other problems endorsed included obtaining adequate counseling services. Although physicians reported that the average patient received counseling, the number of hours per month was relatively small and for many patients may not be sufficient for optimal outcomes. Physicians also endorsed concern about diversion risk and difficulty titrating dose. Initially there was concern about the 30-patient limit, but with the increase to 100 patients, the percentage of physicians endorsing this barrier diminished considerably. It is also interesting to note that few physicians endorsed concern about the effectiveness or safety of the medication and patient acceptance. The lack of concern about patient acceptance may bode well for outreach. It is also encouraging that few physicians perceive the potential oversight by the DEA as a major barrier to prescribing buprenorphine. Originally, the surveys were restricted to physicians that had agreed to be listed on the CSAT Locator List. The purpose of this list, which patients can access on the Internet, was to make it easy for patients to find physicians in their area who could prescribe one of the buprenorphine products in an office-based setting. When access to the entire DEA list was obtained, it seemed likely that the physicians who did not want to be listed on the CSAT Locator List might have different prescribing practices so the two lists were not combined. In analyzing the results separately for the two lists, a few important differences have emerged. For instance, the physicians on the CSAT list were more likely to respond to the survey and to have specialties in the addictions. Fewer physicians on the CSAT list had never prescribed buprenorphine, and the mean number of patients treated was higher. The differences in ongoing buprenorphine educational activities were small but in the direction of more involvement by the physicians on the CSAT list. Of those responding physicians treating at least one patient, there were almost no differences between the two lists in terms of doses used, use of buprenorphine to maintain patients rather than for detoxification, hours of counseling, and percent of patients who were new to treatment. However, those on the CSAT list were more likely to have turned away a patient. In terms of perceived barriers to prescribing, those on the CSAT list were more concerned about financial issues, perhaps reflecting their larger patient load. Other differences were minor, although it is noteworthy that fewer physicians on the CSAT list endorsed diversion as a barrier to prescribing buprenorphine.

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Although these national surveys are the first to document the expansion of treatment and prescribing practices of the physicians who are using buprenorphine products largely in an office-based setting beyond the first year (Stanton et al., 2005), there are several limitations that should lead to caution in interpreting the findings. A major limitation is that the return rate of surveys is low and may be differential, in that physicians who are more engaged in the treatment of opioid-dependent individuals might respond to the survey. Response rates for physicians to mailed surveys, unfortunately, are lower than that for other populations (Asch, Jedrziewski, & Christakis, 1997). Because the surveys are ongoing, several efforts were made at the beginning of 2009 to improve the participation rate. These efforts included increasing the participation reimbursement and sending an initial postcard to notify physicians and their office staff that the survey would soon be sent to them. The survey envelope had information printed on it that this was an important document and participation would be compensated. Following these efforts, participation rates increased to 36% across the first three quarters of 2009, higher than that for 2008 but no greater than rates achieved in earlier years. The percentage of physicians having at least one patient was relatively high, higher than the company reports (Rolley E. Johnson, personal communication) so it is likely that physicians who prescribed were most likely to respond to the survey. This probably results in an estimate of total patients that is much higher than the actual number in treatment, but it does mean that findings generalize to the group of importance, namely, those that are presently prescribing. Related to this limitation, there has been an inconsistent criterion for how many surveys are sent each quarter. Originally, it was a percentage of certified prescribers, but as that number increased, it became impossible to handle the increased number. Another limitation is that physicians needed to recall information over the last 90 days for some of the questions. Although this is a relatively a short period, physicians may not report accurately certain types of information (e.g., exact number of patients). Because the samples were drawn randomly, some physicians may have been surveyed more than once. Between surveys, physicians could have elected to be removed or added to the CSAT Locator List, so that firm conclusions about the true differences between the two sets of physicians require caution. In summary, the findings from these national surveys of physicians certified to prescribe buprenorphine for the treatment of opioid dependence show an expansion in treatment capacity through a continual increase in the number of physicians qualified to prescribe buprenorphine. The findings also suggest an increase in the mean number of patients treated by physicians and a corresponding decrease in patients turned away, which coincide with changes in federal regulations on the number of patients allowed to be treated concurrently. Although the survey is limited by the

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participation rate, it appears that there are few differences between physicians on the CSAT Locator List and those not on the list. Physicians, who were instructed to select from among a list of barriers, were most likely to endorse costs and reimbursement concerns. Thus, the U.S. experiment in expanding medical treatment of opioid dependence to physicians outside of formal substance abuse treatment facilities appears to have resulted in expanded capacity (Kresina, Litwin, Marion, Lubran, & Clark, 2009). Acknowledgments This work was supported by a contract from the manufacturer, Reckitt Benckiser Pharmaceuticals Inc. The contract was initially awarded to Wayne State University (Charles R. Schuster, Principal Investigator). In October 2006, the contract was awarded to CRS Associates, LLC (Charles R. Schuster, Principal Investigator). References Asch, D. A., Jedrziewski, M. K., & Christakis, N. A. (1997). Response rates to mail surveys published in medical journals. Journal of Clinical Epidemiology, 50, 1129−1136. Barry, D. T., Irwin, K. S., Jones, E. S., Becker, W. C., et al. (2008). Integrating buprenorphine treatment into office-based practice: A qualitative study. Journal of General Medicine, 24, 218−225. Fiellin, D. A., & O'Connor, P. G. (2002). Clinical practice. Office-based treatment of opioid-dependent patients. New England Journal of Medicine, 347, 817−823. Fiellin, D. A., Pantalon, M. V., Chawarski, M. C., Moore, B. A., et al. (2006). Counseling plus buprenophine–naloxone maintenance therapy for opioid dependence. New England Journal of Medicine, 355, 365−374. Fudula, P. J., Bridge, T. P., Herber, S., Williford, W. O., et al. (2003). Office-based treatment of opiate addiction with a sublingual-table of buprenorphine and naloxone. New England Journal of Medicine, 349, 949−958. Gunderson, E. W., Fiellin, D. A., Levin, F. R., Sullivan, L. E., et al. (2006). Evaluation of a combined online and in person training in the use of buprenorphine. Substance Abuse, 27, 39−45. Harper, I. (1983). Temgesic abuse. New Zealand Medical Journal, 96, 777.

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