Determinants of the Availability of Hepatitis C Testing Services in Opioid Treatment Programs: Results From a National Study

Abstract

We examined trends and organizational-level correlates of the availability of HCV testing in opioid treatment programs. We used generalized ordered logit models to examine associations between organizational characteristics of 383 opioid treatment programs from the 2005 and 2011 National Drug Abuse Treatment System Survey and HCV testing availability. Between 2005 and 2011, the proportion of opioid treatment programs offering HCV testing increased but largely because of increases in off-site referrals rather than on-site testing. HCV testing availability was higher in opioid treatment programs affiliated with a hospital and those receiving federal funds. Opioid treatment programs providing both methadone and buprenorphine were more likely to offer any HCV testing, whereas opioid treatment programs providing only buprenorphine treatment were less likely to offer on-site testing. HCV testing availability was associated with more favorable staff-to-client ratios. The increasing use of off-site referrals for HCV testing in opioid treatment programs likely limits opportunities for case finding, prevention, and treatment. Declines in federal funding for opioid treatment programs may be a key determinant of the availability of HCV testing in opioid treatment programs.

Headnote

Objectives. We examined trends and organizational-level correlates of the availability of HCV testing in opioid treatment programs.

Methods. We used generalized ordered logit models to examine associations between organizational characteristics of 383 opioid treatment programs from the 2005 and 2011 National Drug Abuse Treatment System Survey and HCV testing availability.

Results. Between 2005 and 2011, the proportion of opioid treatment programs offering HCV testing increased but largely because of increases in off-site referrals rather than on-site testing. HCV testing availability was higher in opioid treatment programs affiliated with a hospital and those receiving federal funds. Opioid treatment programs providing both methadone and buprenorphine were more likely to offer any HCV testing, whereas opioid treatment programs providing only buprenorphine treatment were less likely to offer on-site testing. HCV testing availability was associated with more favorable staff-to-client ratios.

Conclusions. The increasing use of off-site referrals for HCV testing in opioid treatment programs likely limits opportunities for case finding, prevention, and treatment. Declines in federal funding for opioid treatment programs may be a key determinant of the availability of HCV testing in opioid treatment programs. (Am J Public Health. 2014;104:e75-e82. doi:10.2105/AJPH.2013.301827)

HCV is the most common blood-borne infection in the United States. An estimated 3.2 million people in the United States are chronically infectedwithHCV,1makingit3 to5timesmore frequent than HIV.2 Results from a recent study showed that HCV has surpassed HIV as a cause of death in the United States.3 New HCV treatment regimens that are more effective and have fewer side effects have recently become available.4 Unfortunately, fewer than half of the patients living with HCV are aware of their infection.5 This is because infected persons tend to be asymptomatic: in some cases, signs of the disease do not manifest for decades.6 It is thus important to encourage and offer extensive opportunities for HCV testing, especially to the most at-risk populations.6

Advancements in testing technologies (HCV rapid testing)7 and recommendations for the identification of HCV in the general population (i.e., individuals born between 1945 and 1965) present opportunities for increasing the avail- ability of HCV testing.8 Testing could foster increased case finding, as well as earlier linkages to HCV care and treatment services. Ensuring access to HCV testing and increasing awareness of HCV status also could help promote the adoption of preventive behav- iors: for example, engaging in safer injection practices or other protective behaviors. Ulti- mately, this may also have a positive influence on compliance with substance abuse treat- ment and abstinence.9

The Centers for Disease Control and Pre- vention (CDC) recommends routine HCV an- tibody (anti-HCV) testing for injection drug users (IDUs).3,10 IDUs are particularly at risk for HCV infection as a result of sharing and reusing of needles or other injection paraphernalia.6 The estimated anti-HCV prevalence among IDUs ranges from 35% to 65%, depending on factors such as geography and rate of injection drug use.11 Unfortunately, despite the CDC recommendation, IDUs have very low rates of uptake for HCV testing and treatment.12

One factor that may account for such low testing rates is that IDUs less frequently use preventive health care services than do other population groups.13 Outpatient substance abuse treatment programs are one exception: the number of IDUs entering treatment pro- grams has increased in recent years.14 Because injection drug use is strongly associated with opioid use (e.g., heroin), opioid treatment pro- grams are an especially important setting for HCV testing, counseling, prevention, and links to medical care. In the case of HIV testing and case management, on-site services in substance abuse treatment programs have been associ- ated with high-quality prevention, increased service use, earlier initiation of treatment, de- clines in disease transmission, improved treat- ment outcomes for substance use disorders, and links to ancillary services.15-17 Hence integrating HCV testing with substance abuse treatment services, particularly in opioid treat- ment programs, may have similar beneficial effects and is crucial for addressing the HCV epidemic in the United States.18

Unfortunately, trends in the availability of HCV testing services in opioid treatment pro- grams across the nation are not well under- stood.19,20 Large gaps exist in the availability of on-site HCV testing in opioid treatment pro- grams,21-24 with programs that have the largest proportion of IDUs among their clients being less likely to offer on-site HCV testing, even when phlebotomists were on staff.24 Opioid treatment programs often prefer to refer their clients to off-site facilities for HCV testing. Yet off-site referrals for testing and treatment of HCV are associated with significant reductions in the uptake of these services.25

There is also an urgent need to examine the organizational-level characteristics of treatment programs that may serve as facilitators or barriers to the availability of HCV testing services, either on-site or off-site, in the nation's opioid treatment programs.26 HCV testing services may not be offered in opioid treatment programs in the United States for several potential reasons. First, opioid treat- ment programs may lack the required financial resources, including reimbursement and fund- ing, to implement testing services.23,27-29 Sec- ond, treatment programs may not have the human resource capacity (e.g., low staff-to-client ratio) to effectively offer both substance abuse treatment services and ancillary services. Simi- larly, the ownership and affiliations of opioid treatment programs may influence the extent to which they can offer HCV testing services. For example, publicly owned opioid treatment pro- grams might be more likely to have a prevention- driven mission, whereas hospital-affiliated opioid treatment programs may have access to networks that enable them to provide HCV testing services. Organizational-level predictors for HIV testing services in drug abuse treatment programs have been examined extensively, but similar national studies for the provision of HCV testing services are scarce.19 ,3 0 -3 2

We first describe trends in HCV testing availability in the nation's opioid treatment programs between 2005 and 2011. We then examine the role of organizational factors in promoting the availability of HCV testing ser- vices among opioid treatment programs.

METHODS

We defined an opioid treatment program as a physical facility with resources dedicated specifically to treating opiate dependence with methadone or buprenorphine (excluding pri- mary care or physician offices). In 2007, the Substance Abuse and Mental Health Services Administration reported that there were 1108 licensed opioid treatment programs in the United States.33 By 2011, the number of opioid treatment programs increased to 1459, with about 304 000 opioid-dependent indi- viduals receiving services on any given day.14 This study used 2 nationally representative surveys of opioid treatment programs. The first survey included data from opioid treatment programs collected as part of the 2005 Na- tional Drug Abuse Treatment System Survey (NDATSS), a telephone survey, with an 88% response rate.34 For the second survey (2011), we contacted opioid treatment programs that participated in 2005, and to ensure that the 2011 sample was nationally representative and had adequate statistical power, we contacted additional randomly selected opioid treatment programs from the Substance Abuse and Mental Health Services Administration's2011 list. Of all the 2005 and newly selected opioid treatment programs contacted in 2011, 200 completed surveys, for a response rate of 86.6%. The analysis included 187 and 196 opioid treatment programs from 2005 and 2011, respectively, for a total of 383 opioid treatment programs.

We followed established methods that max- imize reliability and validity in telephone sur- veys.35 These methods include pretesting the survey with a random sample of programs and performing extensive computer reliability checks to signal interviewers of inconsistent or infeasible responses (e.g., percentage of clients with various demographic characteristics should sum to 100%). Interviewers then worked with respondents to resolve inconsis- tencies. Results were further scrutinized for reliability and validity. Reliability checks in- cluded comparisons of reported totals (e.g., total revenue) with the sum of reported detail (e.g., revenues by source); comparison of responses to related questions; comparison of responses be- tween director and supervisor; and, for panel programs, comparison of responses over time. Results from several analyses provided support for NDATSS data reliability and validity.32,34

Study Variables

Availability of HCV testing services. The out- come measure of interest was whether an opioid treatment program offered HCV testing (availability of HCV testing services in opioid treatment programs). We asked opioid treat- ment program directors whether their staff routinely provide on-site or off-site HCV testing services to clients. We used responses to these 2 questions (yes or no) to categorize programs as providing on-site HCV testing (i.e., they responded "yes" to providing on-site HCV test- ing), off-site HCV testing (i.e., they responded "no" to the question about on-site testing but responded "yes" to the off-site testing question), or no testing (i.e., they did not respond "yes" to either question).

Independent variables. An opioid treatment program manager reported sociodemographic characteristics of clients, including the propor- tion of clients from the most recent complete fiscal year who were African American, non- Hispanic White, or Hispanic. The manager also reported the percentage of clients in the most recent complete fiscal year whose use of drugs involved injection with needles. We used this information to create a categorical variable describing the prevalence of injection drug use among opioid treatment program clients (< 25%, 25%-74%, or [double dagger] 75%). We created 2 dummy variables identifying opioid treatment programs with fewer than 10% Hispanic or African American clients.

We examined several variables describing resource availability in opioid treatment pro- grams. This included an assessment of human resources available to conduct or support testing. We combined 2 data components: (1) the number of full-time-equivalent staff (i.e., individuals employed by the program who worked 35 hours per week or more in the most recent complete fiscal year) and (2) the number of clients served by the program during the same period. We created a staff-to-client ratio by dividing the number of full-time-equivalent staff by the number of clients. We also mea- sured sources of revenue for each opioid treatment program by using (1) the percentage of total revenue received by the unit directly from the federal government, including Medi- care and block grants but excluding courts and prisons; and (2) the percentage of total revenue received by the unit from private insurance companies, including health maintenance or- ganizations and preferred provider organiza- tions. We created a dummy variable for each measure (0-1) set to 1 if the program received at least some of its revenue from either source.

Measures of opioid treatment program characteristics also included program owner- ship (private for-profit, private not-for-profit, or public) and affiliation. Program directors were asked if their unit had an affiliation with a hospital. We used a dummy variable coded as 1 for " yes " and 0 otherwise. We used data provided by opioid treatment program direc- tors to measure whether the treatment pro- gram currently held accreditation from CARF International (formerly known as the Commis- sion on the Accreditation of Rehabilitation Facilities). Finally, we examined the influence of pharmacological method of treatment. We included an indicator for whether the treat- ment program provided methadone treatment only, buprenorphine prescription only, or both methadone and buprenorphine prescription.

Analysis

The current analysis included 187 opioid treatment programs in 2005 and 196 in 2011. We first measured changes in organizational characteristics of opioid treatment programs between 2005 and 2011. We used the Pear- son v2 test for categorical variables and the t test for continuous variables to test for differences in the organizational characteristics of opioid treatment programs between 2005 and 2011.

We then estimated ordered logit models of the availability of HCV testing services in opioid treatment programs. Specifically, the dependent variable was coded as follows: 1 = no testing services, 2 = off-site testing, 3 = on-site testing. Ordered logit models estimate 1 equation for each pair of levels of the dependent variable with the assumption that the effect of each covariate is the same across all categories of the dependent variable.36,37 This means, for example, that the odds ratio (OR) associated with hospital affiliation is the same when we compare opioid treatment pro- grams with no testing services with opioid treatment programs with off-site testing as when we compare opioid treatment programs with no testing with opioid treatment programs with on-site testing. This is known as the pro- portional odds assumption.

In standard ordered logit models, the pro- portional odds assumption is strong, because it must be met for all coefficients in the model. We thus used a less restrictive extension of the ordered logit models, known as generalized ordered logit models.38 In generalized ordered logit models, we make only a "partial" pro- portional odds assumption: specific coefficients are allowed to vary across categories of the dependent variable, whereas other coefficients are constrained to be equal. To decide which coefficients to constrain, we conducted Wald tests of the proportional odds assumption for each covariate defined earlier. We estimated these models separately by year to investigate possible changes in patterns of coefficients over time. For each model, we calculated robust SEs. All analyses were performed with Stata version 12 (StataCorp LP, College Station, TX), including the GOLOGIT2 add-on.37

RESULTS

Table 1 describes changes in the character- istics of opioid treatment programs between 2005 and 2011 and shows notable differ- ences. The proportion of opioid treatment programs receiving federal funding declined significantly: in 2005, 37.9% of opioid treatment programs received at least some of their revenue from federal government fund- ing versus only 21.4% of opioid treatment programs in 2011 (P < .001). In 2005, the average staff-to-client ratio in opioid treatment programs was 4 staff members per 100 clients versus 5 staff members per 100 clients in 2011. Finally, method of treatment changed over time, with several opioid treatment pro- grams diversifying their treatment approach. The proportion of opioid treatment programs that used buprenorphine as the only method of treatment increased from 20.3% in 2005 to 29.0% in 2011. On the other hand, methadone-only treatment programs de- clined from 66.8% in 2005 to 46.9% in 2011.

HCV Testing in Opioid Treatment Programs in 2005 and 2011

Figure 1 illustrates changes in the availabil- ity of HCV testing services in opioid treatment programs. The proportion of opioid treatment programs that reported that they did not pro- vide any HCV testing services to their clients (i.e., no on-site or off-site testing) declined from 27% in 2005 to 10% in 2011. Concomitantly, however, the proportion of opioid treatment programs offering on-site HCV testing also declined from 53% in 2005 to only 34% in 2011. Instead, most opioid treatment programs in 2011 offered only off-site HCV testing options for their clients: 20% of opioid treat- ment programs had only off-site options in 2005 compared with 56% of opioid treatment programs in 2011.

Multivariate Analysis

Table 2 shows the predictors of HCV testing availability in opioid treatment programs in 2005 and 2011, respectively. After we ad- justed for other covariates in the model, the likelihood that an opioid treatment program offered any category of HCV testing was associated with several organizational charac- teristics.

In 2005 (Table 2), results from generalized ordered logit models showed that the avail- ability of HCV testing services in opioid treat- ment programs was associated with funding from the federal government and staff-to-client ratio. Opioid treatment programs that received at least some of their revenue from federal grants were significantly more likely to offer HCV testing services to their clients than were other opioid treatment programs (OR = 2.03; 95% confidence interval [CI] = 1.01, 4.07), as were opioid treatment programs with higher staff-to-client ratios (OR = 1.69; 95% CI = 1.16, 2.46). The proportional odds as- sumption was rejected for only 2 variables. Opioid treatment programs that served a high proportion of African American clients were significantly less likely to offer any HCV testing, compared with no testing (OR = 0.30; 95% CI = 0.11, 0.80). Hospital affiliation was asso- ciated with significantly higher availability of on-site HCV testing (OR = 7.71; 95% CI = 2.89, 20.53).

In 2011 (Table 2), the availability of HCV testing services remained associated with re- ceipt of funding from the federal government, although the strength of this association de- clined slightly (OR=1.88;95% CI=0.91, 3.89). On the other hand, the availability of HCV testing was no longer significantly asso- ciated with staff-to-client ratios (OR = 1.50; 95% CI = 0.86, 2.61). The proportional odds assumption was rejected for several variables, including ownership and hospital affiliation. In particular, although there were too few cases to estimate the association of hospital affiliation with the likelihood of offering only off-site testing services, hospital affiliation was signifi- cantly associated with on-site testing (OR = 3.92;95% CI=1.35, 11.38).

The method of opioid dependence treat- ment was also associated with the availability of HCV testing services. Opioid treatment programs that prescribed methadone and buprenorphine were more likely to offer HCV testing options to their clients (OR = 2.62; 95% CI = 1.26, 5.45). However, opi- oid treatment programs that offered only buprenorphine treatment were significantly less likely to offer on-site HCV testing ser- vices (but not off-site testing) than were other opioid treatment programs (OR = 0.32; 95% CI=0.11,0.90).

DISCUSSION

We examined trends in the availability of HCV testing services and their organizational determinants in the nation's opioid treatment programs. An increasing number of opioid treatment programs offered HCV testing ser- vices to their clients in 2011 than in 2005, but fewer opioid treatment programs offered on- site HCV testing services. Instead, they in- creasingly offered only referrals for HCV test- ing at off-site facilities. In 2005, 53% of the nation's opioid treatment programs offered on-site HCV testing. Alarmingly, only 34% of opioid treatment programs offered on-site HCV testing to clients in 2011. Because off-site referrals are associated with lower uptake of testing and treatment services, this trend con- stitutes a significant threat to HCV control in the United States.

We found that structural changes in several organizational characteristics of opioid treat- ment programs may explain the trend toward less on-site HCV testing observed between 2005 and 2011. In particular, HCV testing availability was consistently associated with receipt of federal funding: federally funded opioid treatment programs were more likely to offer on-site testing to their clients than were other opioid treatment programs, both in 2005 and in 2011. At the same time, the proportion of federally funded opioid treatment programs among all opioid treatment programs declined sharply between 2005 and 2011. The de- clining availability of federal funding thus likely played a key role in explaining the observed adverse trends in on-site HCV testing avail- ability. The importance of funding for increas- ing on-site availability of services was already noted in a review of the role of organization and management factors in substance abuse treatment.26 Reversing the trend in the avail- ability of on-site HCV testing services in opioid treatment programs thus may require new funding for opioid treatment programs to fa- cilitate the integration and sustainability of HCV testing and treatment services.

Written policies or guidelines for HCV test- ing services as an important factor in increasing access to funds also may be required. A study reported that substance abuse treatment pro- grams do not adequately access available funds, particularly state funds.29 Although opioid treatment programs need better pro- gram funding and adequate material resources to increase on-site testing for HCV, mecha- nisms to facilitate and enhance treatment pro- grams' capacity to access available funds are also needed. The absence of coordination and underfunding of public health services have been associated with the health system being inadequately positioned to improve awareness, prevention, diagnosis, and treatment of HCV.39

Our results also show that affiliation with a hospital was associated with increased likeli- hood of on-site HCV testing. This finding is supported by previous studies that examined the effects of hospital affiliation on service delivery and quality of care in substance abuse treatment programs. For example, treatment units affiliated with hospitals have been shown to provide more physical examinations and routine primary care.40 Another study showed that hospital affiliation is associated with a greater likelihood of treatment availability and the use of medications for treating sub- stance abuse.41 Our finding thus suggests that addressing the HCV epidemic among at-risk populations will likely require the development of collaboration between substance abuse treatment programs and testing and care sites, including hospitals and other settings.

Establishing links with a broader range of sites is particularly important because there has been a decline in the proportion of opioid treatment programs affiliated with hospitals between 2005 and 2011 (Table 1). Addition- ally, considering the overall increase in HCV testing services over time (driven mostly by increases in off-site relative to on-site testing) and evidence suggesting that referrals do not necessarily translate into uptake of services, future studies should test approaches to effec- tively establish links to off-site facilities that can increase uptake of testing and access to treat- ment.

Opioid treatment programs that use bupre- norphine as the only approach to treatment were less likely to offer on-site HCV testing services relative to no testing. Other studies have compared hepatitis services offered at methadone maintenance treatment programs with other program types and showed that drug treatment programs were 4.5 times more likely to provide HCV services if they dis- pensed methadone.42 Another study found that approximately 66% of methadone pro- grams versus only 33% of drug-free programs offered HCV screening to all patients.43 The types of clients served by buprenorphine pro- grams may explain this variation in HCV testing availability by method of opioid dependence treatment. For example, buprenorphine-only programs may have fewer clients who inject drugs or a mix of clients considered to be less at risk for contracting HCV. This may influence the mission or focus of these programs and influence their likelihood to offer preventive 44 services.

Other aspects of treatment programs, par- ticularly characteristics of providers, may offer some insight into this phenomenon. Several studies showed that deficits in providers' knowledge of HCV infection prevalence, available tests, testing procedures, and treat- ment of HCV may be a barrier to the availability of HCV testing services in substance abuse treatment.45-47 Further study of these dynam- ics in opioid treatment programs, especially buprenorphine-only programs, is critical: the proportion of buprenorphine-only programs in the nation has increased significantly since 2005.48 Although buprenorphine is an effective approach to addiction treatment,49 it may have unanticipated and adverse effects on the de- livery of more comprehensive health services, especially for individuals at high risk for con- tracting and transmitting HCV, that must be investigated. Finally, we found that staff-to-client ratio was associated with an increased likelihood of the availability of HCV testing (although not significantly in 2011). The availability of human resources may support new practices. Particu- larly, increases in staff may motivate greater focus on activities and practices related to ancillary services, including HCV testing.

Study Limitations

This study had several limitations. First, the NDATSS focused on organizational-level mea- sures and had limited questions about clients of opioid treatment programs. We thus could not measure uptake of HCV testing among clients of opioid treatment programs that offered HCV testing. We also could not identify the set of opioid treatment programs where it would be particularly urgent to develop on-site HCV testing opportunities (e.g., because clients had limited HCV testing history or because they were more likely to be infected with HCV, thus suggesting a high yield of HCV testing). Our data also did not provide a comprehensive as- sessment of the availability of other HCV-related services in opioid treatment programs, including counseling, care, and treatment services, nor did they assess opportunities for links to care after HCV testing among opioid treatment program clients.

Second, the NDATSS data did not permit assessing whether the relation between key covariates and HCV testing availability was causal. For example, the observed association between HCV testing and receipt of federal funds could be a result of reverse causality: opioid treatment programs that offer HCV testing on-site may be more likely to receive federal funds because managers of these opioid treatment programs have more experience with applications for federal funding. The causal effects of federal funding (and other covariates) cannot be isolated because only a limited number of opioid treatment programs are followed longitudinally. Measuring the causal effects of these key organizational char- acteristics will require panel data in conjunc- tion with sophisticated econometric techniques. Finally, the sample size available in each wave of the NDATSS may occasionally be limited. It was thus not possible to investigate possible interactions between organizational factors or between client characteristics and organiza- tional factors. Despite these limitations, the study addressed an important health services delivery problem with considerable implica- tions for substance-abusing patients and pop- ulation health. Results from this study suggest that investments, treatment practices, and pol- icies are needed to facilitate organizational change and promote offering of on-site HCV testing services in opioid treatment programs.

Conclusions

In an era of advancements in testing tech- nologies (introduction of rapid HCV antibody testing) and the advent of more effective treatments for HCV, early diagnosis, facilitated by increased availability of on-site HCV testing in the nation's opioid treatment programs, is critical. This is particularly important because providing health services on-site is more effective in reaching patients compared with providing referrals to an outside site.16 Inter- ventions that address organizational-level barriers (i.e., availability of funding and the capacity of treatment programs to effectively access the available funds) are essential to increasing the availability of on-site testing. Recent efforts to increase awareness of HCV infection status and address the HCV burden in the nation (i.e., the recent release of recom- mendations for the identification of HCV among individuals born during 1945-1965) also may present opportunities (increased funding, political will) for increasing the avail- ability of HCV testing in opioid treatment programs. Notably, initiatives that promote the adoption of rapid HCV testing in opioid treat- ment programs also may have an important role in accelerating the ability of opioid treat- ment programs to offer on-site HCV testing. Given the high prevalence of HCV infection among persons with drug use disorders, particularly IDUs, and increasing mortality from HCV, the importance of on-site HCV testing services, early detection, and treatment, as well as reductions in transmission, cannot be overstated. Future research should examine barriers to the adoption of HCV testing ser- vices, with a focus on strategies for enabling the implementation and sustainability of rapid HCV testing. These efforts also must consider organizational and patient-level factors that may influence uptake of testing services. j

References

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