Literature Review - Methadone Maintenance Treatment

3. Factors that Influence the Effectiveness of MMT

Despite the lack of consensus about how treatment should be delivered, there is a significant amount of information about individual and program factors that influence the effectiveness of methadone maintenance treatment programs -primarily in terms of client/patient retention in treatment.

3.1 Individual Factors

Individual circumstance or status may affect treatment outcomes either positively or negatively. As Lowinson et al. (1997, 412) note, however, many people in treatment have to contend with circumstances that create significant obstacles to success in treatment: "For the majority of inner-city patients, lack of education and job skills, child care, unemployment, and poverty continue to have an adverse impact on socially productive behaviour and treatment response."

Strain (1999b, 76) cautions that predicting outcomes in treatment can be difficult: "...no single characteristic or set of characteristics can fully predict those who will do well or poorly in treatment." Strain also notes that some client/patient characteristics and some early treatment results are associated with better outcomes (and refers to McLellan), but points out that this information should not be used to allocate treatment slots.

Based on his review of the evidence, Darke (1998b, 83-84) argues that many of the problem factors that tend to be associated with poorer prognoses can actually be improved by participation in treatment programs, particularly through "careful clinical management". For example, he cites the work of Caplehorn et al. and Grönbladh et al. which has shown that methadone maintenance treatment can significantly reduce the risk of morbidity and mortality related to injection drug use, and notes that psychiatric distress and drug use (including cocaine use) may also be reduced by participation in treatment. Furthermore, Darke concludes that the risk of diversion can be addressed by "cautious clinical judgement" in prescribing take-home doses.

According to evidence reviewed by Ward, Mattick and Hall (1998b, 331), programs should use information about problem characteristics among clients/patients to enhance their efforts to retain those people in treatment. In their view, "patients should not be encouraged to leave methadone maintenance before they show....signs of rehabilitation (i.e., employment, stable social adjustment, no illicit drug use, etc.)."

Table 3 provides some information about individual characteristics that have been linked to treatment outcomes.

Table 3: Individual Factors

Individual characteristic/factor	Associated Outcomes
Age	Older age is the characteristic most consistently associated with better outcomes (McLellan and Farley et al., as cited in Strain, 1999b, 76).
Relationship-related factors	Being married is associated with better outcomes (McLellan and Farley, et al., as cited in Strain, 1999b, 76). Intact social support network is associated with success in methadone maintenance treatment (McLellan, Simpson and Sells, Ball and Ross and Anglin and Hser, as cited in National Institute on Drug Abuse, 1995, 1-45). The evidence reviewed by Ward et al. (1998b, 330-331) suggests that clients/patients who have "reasonable social support" have a higher likelihood of success if they complete methadone maintenance treatment. Not living with a family or partner is one of the characteristics that makes a client/patient likely to relapse to drug use and/or criminal activity if they leave treatment.
Employment	Poor employment history is associated with poor treatment retention (McLellan and Farley et al. as cited in Strain, 1999b, 76; National Institute on Drug Abuse, 1995). Evidence reviewed by Ward et al.(1998b, 330) indicates those clients/patients who do not find employment before, during or after methadone maintenance are most likely to relapse to drug use and/or criminal activity if they leave treatment. Becoming employed is one of the factors associated with a better chance of success for clients/patients who complete treatment.
Mental health status	Evidence reviewed by Darke (1998b, 82) indicates that psychological distress is common and may impede outcomes, but methadone maintenance treatment may "contribute to an amelioration of patients' symptoms of depression and anxiety." Psychological problems are associated with poor treatment retention (McLellan and Farley et al., as cited in Strain, 1999b, 76). Evidence reviewed by Darke (as cited by Ward, Mattick and Hall, 1998f, 434) suggests that it is the "overall severity" of clients'/patients' psychiatric problems that is related to poorer treatment outcomes, rather than specific diagnoses.
Criminal history	Those with minimal criminal involvement are likely to have better treatment outcomes (McLellan; Simpson & Sells; Ball & Ross; Anglin & Hser, as cited in National Institute on Drug Abuse, 1995, 1-45). Evidence reviewed by Ward et al. (1998b, 331) indicates that one of the success factors for clients/patients who complete MMT is having "little history of criminal activity." Those clients/patients with a " longer and more extensive criminal history" are most likely to return to using drugs and/or criminal activity if they leave treatment. A history of criminal activity is associated with poor treatment retention (McLellan and Farley et al., as cited in Strain, 1999b, 76).
Drug use	Evidence reviewed by Ward et al. (1998b, 331) indicates that clients/patients with a "longer and heavier history of opioid use" are most likely to return to using drugs and/or engaging in criminal activity if they leave treatment. According to evidence reviewed by Darke (1998b, 76) drug use other than heroin (e.g., benzodiazepine, cocaine) is associated with riskier behaviours and poorer psychological functioning and may indicate a poorer prognosis. Amount of illicit opioid use during first two weeks of treatment is predictive of subsequent rates of opioid use (as measured by urine samples) (Strain et al, as cited in Strain, 1999b, 76). Amount of cocaine use during first two weeks of treatment is predictive of subsequent rates of cocaine use (as measured by urine samples) (Strain et al., in Strain, 1999b, 76).
Behaviour	According to evidence reviewed by Ward et al. (1998b, 331) clients/patients who leave treatment "against staff advice" or who exhibit "little behaviour change during treatment" are most likely to return to using drugs and/or engaging in criminal activity if they leave treatment.
Treatment readiness/ motivation	Treatment readiness, "measured with items from the CMRS [circumstance, motivation, readiness and suitability] (De Leon & Jainchill, 1986; Joe, Simpson and Broome, 1998) was found to be significantly related to therapeutic involvement" (Fletcher & Battjes, 1999, 83). Motivation at intake is a strong determinant of therapeutic involvement (Joe, Simpson and Broome, 1999, Abstract) Patients expressing greater confidence and commitment after three months of treatment generally began with higher motivation at intake (Broome et al., 1999, Abstract).
Therapeutic involvement	Therapeutic involvement - when "measured in terms of rapport with counsellor, confidence in treatment, and commitment to treatment" - was a significant predictor of retention (Fletcher & Battjes, 1999, 83). Therapeutic involvement is strongly determined by motivation at intake (Joe et al., 1999, Abstract).

3.2 Program Factors

Some researchers have emphasized the importance of the manner in which treatment is provided. For example, Magura, Nwakeze and Demsky (1998a, 57) found evidence that events during treatment are critical factors for retention in treatment: In this study, "only two out of 16 pre-treatment variables (pre-treatment variables include individual characteristics), compared with five out of six during-treatment variables had significant effects on retention...."

A number of program characteristics or factors have been associated with improved treatment outcomes - primarily improvements in client/patient retention in treatment. The emphasis on retention in treatment is key because, according to studies reviewed by Ward et al. (1998b, 312), longer lengths of time spent in treatment are related positively to treatment outcomes.

Their introduction to the text edited by Ward, Mattick and Hall (1998a, 3) notes that the characteristics that appear to affect treatment outcome are: methadone dose, duration of treatment, and ancillary services. Based on their analysis of the evidence, Hall et al. (1998b, 51-52) note that, in fact, the most effective programs are those that most closely resemble the original Dole and Nyswander model and offer: higher doses, and comprehensive treatment aimed at maintenance rather than abstinence. As they explain: "Analyses of the characteristics that predict the variations between programs in retention, drug use and criminality have generally supported the original model of Dole and Nyswander in showing that programs with higher doses, a maintenance goal and ancillary services have better outcomes than programs that use lower doses and aim to achieve abstinence."

Table 4 lists the program-related factors that have been associated with treatment outcomes (see also Part 4.0, Part 5.0 and Part 6.0) . These program factors also relate to the needs of specific groups (see also Part 7.0).

Table 4: Program-Related Factors Associated With Treatment Outcomes

Program-Related Factors	Associated Treatment Outcomes
Emphasis on retention	Retention of clients/patients is necessary for any changes to occur. Consequently, retention is an accepted indicator of program functioning (Ward, Mattick and Hall, 1998h, 214). Retention in treatment is a key factor in achieving positive treatment outcomes (see Section 4.1). Consistent with numerous previous evaluations of MMT, the Drug Abuse Treatment Outcome Studies (DATOS) found that retention in MMT is an important predictor of treatment outcomes (Fletcher & Battjes, 1999, 82). Longer time spent in MMT increases likelihood of remaining crime-free, and reducing use of heroin (Simpson & Sells; Ball & Ross, as cited in National Institute on Drug Abuse, 1995, 4-11,4-14).
Maintenance orientation	Recent research reviewed by Ward et al. (1998b, 331) indicates that a maintenance (rather than abstinence) orientation is one of the program characteristics linked to successful retention. According to Ward et al. (1998b, 324), citing research by Caplehorn et al. and McGlothlin and Anglin, programs with a "long-term maintenance philosophy" have better retention rates than programs with a "short-term maintenance philosophy" (independent of treatment goal).
Client/patient-centred approach	Identifying and meeting individual treatment needs is associated with treatment success (Joe, Simpson & Hubbard, as cited in National Institute on Drug Abuse, 1995, 1-38) (See Section 4.2 ) There are important considerations in meeting the needs of specific groups of clients/patients (see Part 7.0)
Accessibility	Recent research reviewed by Ward et al. (1998b, 331) indicates that some of the program factors that are most likely to improve retention include accessibility, affordability and convenient hours of operation. According to the TOPS study, clinic accessibility is related to retention (Condelli & Joe et al., as cited in Ward et al, 1998b, 325). According to Maddux and colleagues (as cited in Ward et al., 1998b, 325), fee-for-service methadone has poorer retention rates than free treatment. Factors that impede accessibility, such as treatment fees, have been found to have an adverse effect on retention (Maddux, as cited in National Institute on Drug Abuse, 1995, 1-50).
Integrated, comprehensive services	Comprehensive services and the integration of medical, counselling and administrative services are associated with better treatment outcomes (Ball & Ross, as cited in National Institute on Drug Abuse, 1995, 1-38) (See Section 4.3). The most effective opiate agonist maintenance programs provide methadone as well as other medical, behavioral, and social services (Leshner, 1999).
Medical care	Given the prevalence of (often neglected) medical conditions among people who are dependent on opioids, the provision of primary and specialist medical treatment is a key aspect of MMT. Lowinson et al. (1997, 410) notes that "providing primary care to substance abusers in methadone maintenance clinics could reduce the demand placed on emergency rooms and the need for hospitalization and thereby drastically cut the overall cost of their care." See also Sections 7.4 to 7.7
Other substance use treatment	Given the prevalence of multiple substance use behaviours among people who are dependent on opioids, the provision of other substance use treatment is a key aspect of MMT (See Section 7.1).
Counselling	Based on their review of the evidence, Mattick, Ward and Hall (1998, 296) conclude that "there is reasonable evidence to suggest that counselling does add to the effectiveness of methadone maintenance treatment for some patients." Greater amounts of counselling services are associated with better outcomes (McLellan; Strain et al., as cited in Strain, 1999b, 76). There is evidence that comprehensive counselling services provided by experienced counsellors is a factor in treatment success (Ball & Ross, as cited in National Institute on Drug Abuse, 1995, 1-38). There is a strong relationship between session attributes and therapeutic involvement. Session attributes were the number of individual counselling sessions, the number of times drugs/addiction or related health topics were discussed, and the number of times other topics were discussed in the first month of treatment (Joe et al., 1999, 117, 122). "...patients expressing greater confidence and commitment after [three] months of treatment generally began with higher motivation at intake, had formed better rapport with counselors, and attended counseling sessions more frequently" (Broome et al., 1999, Abstract). See Section 4.3.1
Mental health services	Given the prevalence of mental health problems among people who are dependent on opioids, the provision of mental health services is a key aspect of MMT (See Section 7.7).
Health promotion, disease prevention and education	Given the prevalence of risk behaviours for HIV, HCV and other blood-borne pathogens among people who are dependent on opioids, the inclusion of health promotion and disease prevention and education strategies is a key aspect of MMT (See Sections 7.5 and 7.6).
Ancillary services (in general)8	Newman and Peyser (as cited in Mattick, 1998, 269) have suggested that there is a widespread belief that ancillary services are the most important components of effective methadone maintenance treatment programs, despite the fact that there is relatively little research evidence to support this idea. Joe et al. (as cited in Ward et al.,1998b, 324) analyzed data from the TOPS study and found that increased retention was associated with providing clients/patients with access to medical, psychological and financial services during treatment. Condelli (as cited in Ward et al., 1998b,324) also analyzed TOPS data and found that increases in retention were associated with higher ratings of the quality of services by clients/patients. Research by Maddux et al. (as cited in Ward et al.,1998b, 325) indicates that services need to be tailored to the clients'/patients' needs, and programs should take into account the extent to which clients'/patients' are interested in using such services. A study by McLellan et al. (as cited in Bell, 1998a, 169) found that the greater the level of services provided, the better the treatment outcomes. " those programs with higher average involvement by patients used more social and public health services, maintained more consistent attendance at counselling sessions, and served patients who collectively has more similar kinds of needs (Broome et al., 1999, Abstract)  " patient confidence was higher when referred services were more readily accessible...even patients without unmet needs have higher confidence in programs that maintain higher levels of service utilization. Thus, the therapeutic environment appears to be more positive when a broad array of patient needs are being addressed" (Broome et al., 1999, 133). Based on their review of the evidence, Hall et al. (1998b, 51) conclude that intensity of ancillary services is a probable factor in treatment outcomes. See Section 4.3.2.
Program policies	Clear policies and procedures are linked to longer retention (Ball & Ross, as cited in Lowinson et al., 1997, 412). Clinic policies are one of the most important factors for retention (D'Ippoliti et al., 1998, 171).
Admission Criteria	In a study by Bell et al. (as cited in Ward et al., 1998a, 193), the consequences for individuals not admitted to treatment were a 16-month delay in their entry into treatment, and their exposure in the interim to the risks of incarceration and death. Given the potential for methadone maintenance treatment to reduce the harms associated with opioid dependence - and the consequences of not providing treatment, restrictive admission criteria should be avoided (See Section 5.1).
Assessment	According to studies by Bell et al. and Woody et al. (as cited in Ward et al., 1998b, 326), programs that provide rapid vs. slow assessment have better retention. A study by Maddux et al (as cited in Ward et al., 1998b, 326) did not find a statistically significant difference, but did find that more of the clients/patients in a rapid assessment group initiated treatment, and there was a trend to increased retention among this group. "...even very early events in treatment [i.e. during first month] can have effects on patient decision to remain [one] year later" (Joe et al., 1999, 122). See Section 5.2.
Dosage	Based on the evidence reviewed, the National Institute on Drug Abuse (1995, 1-38 to 1-40) concludes that the "establishment of adequate dosing policies" is associated with treatment success and "...methadone dosage should be based on the patient's individual needs, the goals of treatment, and progress in treatment." The evidence reviewed by Strain (1999b, 76) indicates that higher dose is associated with better treatment outcomes. Dose is one of the important factors for improved retention (D'Ippoliti et al., 1998, 171) Recent research reviewed by Ward et al. (1998b, 331) found that programs with a flexible dosage policy are more likely to meet clients'/patients' needs. Studies by Grabowski et al and Pani et al. (as cited in Ward et al., 1998b, 325-326) indicate that providing take-home doses is related to retention. Flexible take home doses are an influential factor in retention (Lowinson et al., 1997, 412). See Section 5.3
Methadone maintenance treatment during pregnancy	Providing methadone maintenance treatment for pregnant women who are dependent on opioids has been shown to be effective in improving maternal and infant outcomes (See Table 1; See Section 7.3).
Duration of treatment	Length of time in treatment is the major factor in successful outcomes (Ball & Ross, as cited in Lowinson, et al., 1997, 412) Studies reviewed by Ward et al. (1998b, 312) indicate that longer length of time in treatment is associated with improved treatment outcomes after leaving treatment. See Section 5.4
Urinalysis and monitoring of drug use during treatment	Recent research reviewed by Ward et al. (1998b, 331) suggests that programs with a "non-punitive approach to illicit drug use"are more likely to meet the needs of clients/patients. According to Stitzer et al. (as cited by Ward et al., 1998b, 326), using negative consequences, eg. reduced doses of methadone, to respond to illicit drug use during treatment has been co-related, in a number of studies, with clients/patients leaving treatment. See Section 5.5.
Tapering from methadone	Given the difficulties associated with tapering from methadone, a client/patient-centred approach to making this decision and engaging in this process is a key aspect of MMT. See Section 5.6
Human resources	"According to Kreek (1991), adequate staff numbers, training, and concern for patient needs and high staff stability (low staff turnover) are associated with improved patient outcomes" (Centre for Substance Abuse Treatment, as cited in National Institute on Drug Abuse, 1995, 1-39). High staff morale is associated with better treatment outcomes (Lowinson et al., 1997, 412). See Section 6.1
Practitioner attitudes	According to recent research reviewed by Ward et al. (1998b, 331), program staff with positive attitudes to methadone treatment and to clients/patients is a factor that makes retention more likely. "...there are positive consequences of a supportive and committed recovery environment for patient engagement and eventual success" (Broome et al., 1999, 134). See Section 6.1
Quality of team-client/patient relationships	"...patients expressing greater confidence and commitment after [three] months of treatment generally began with higher motivation at intake, had formed better rapport with counselors, and attended counseling sessions more frequently" (Broome et al., 1999, Abstract). "Factors that influence longer retention are...trusting and confidential relationships between the patients and the program staff" (Lowinson et al., 1997, 412) Based on their review of the evidence, Hall et al. (1998b, 51) conclude that "other relevant factors [in programs' effectiveness in reducing drug use and criminal activity] probably include the quality of the therapeutic relationships between patients and staff." See Section 6.1
Training	Staff training is associated with better treatment outcomes (Kreek; Centre for Substance Abuse Treatment, as cited in National Institute on Drug Abuse, 1995, 1-39). See Section 6.1
Program environment	Although relatively little research has been done in this area, "the organization of treatment is almost certainly an important component of effectiveness" (Bell, 1998a, 166). See Section 6.2

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