|Day treatment versus enhanced standard methadone services for opioid-dependent patients: a comparison of clinical efficacy and cost
|Avants S K, Margolin A, Sindelar J L, Rounsaville B J, Schottenfeld R, Stine S, Cooney N L, Rosenheck R A, Li S H, Kosten T R
This is a critical abstract of an economic evaluation that meets the criteria for inclusion on NHS EED. Each abstract contains a brief summary of the methods, the results and conclusions followed by a detailed critical assessment on the reliability of the study and the conclusions drawn.
An intensive day treatment programme for unemployed, inner-city methadone patients. The day treatment programme was a 5 hours per day, 5 days per week, manual-guided programme. It was facilitated by the same master's-level therapists who provided the comparator programme and which provided groups in five general areas: substance abuse treatment, physical and emotional health, community development, development of alternative reinforcers, and basic daily living skills.
Economic study type
Unemployed, inner-city methadone patients. Study participants were recruited from a community-based methadone maintenance programme.
Primary care and community. The economic analysis was carried out in the USA.
Dates to which data relate
Effectiveness and resource use data appear to correspond to the 3-year treatment phase (between 1994 and 1996). The price year was 1995.
Source of effectiveness data
The evidence for the final outcomes was based on a single study.
Link between effectiveness and cost data
Costing was conducted retrospectively (based on attendance records and patient charts) on the same patient sample as that used in the effectiveness analysis.
Power calculations do not appear to have been used prospectively to determine the sample size. However, a retrospective power analysis showed that the study had 90% power to detect a clinically meaningful difference (20%) relative to the objective outcome measure of drug use. Of the 308 patients who met the inclusion criteria, 291 (with a mean age of 36.8 years (+/- 6.9)) began treatment. 145 followed the day treatment programme and 146 received enhanced standard care. 237 people completed treatment : 82% of those assigned to the day treatment programme and 81% of those receiving enhanced standard care. 17 randomly assigned patients were lost before treatment began.
This was a randomised, controlled trial carried out in a single centre. The duration of the follow-up was 6 months. 25% of the group assigned to the day treatment programme were lost to follow-up and 27% of the enhanced standard care group were lost to follow-up. Urn randomisation was performed. Both interventions were 12 weeks in duration, manual-guided, and provided by master's-level clinicians.
Analysis of effectiveness
The principle used in the analysis of effectiveness appears to have been treatment completers only. The objective outcome measure of the study was drug use based on an objective test: urine toxicology screens were administered twice weekly for patients in both treatment intensities. The other outcome measures were severity of addiction-related problems, and prevalence of HIV risk behaviours. The assessment battery, administered before treatment, at the end of 12 weeks of treatment, and 6 months after completion of treatment, included the Addiction Severity Index and the HIV Risk Assessment Battery. An attempt was made to determine whether it was possible to identify subgroups of patients in methadone maintenance programmes who differentially benefited from the two treatment intensities. Patient satisfaction ratings after treatment were also evaluated. The effects of covariates on the study outcome measures were assessed. The Kaplan-Meier method and log rank test were used to compare the survival time to dropout. It was reported that those who completed treatment did not differ from the treatment dropouts in terms of baseline demographic and clinical characteristics.
The mean (SD) survival time to dropout for those who completed the study period was 10.9 (2.7) weeks for the day treatment programme and 10.7 (2.9) weeks for the enhanced standard care, (p=0.68). There were no differences between the groups in rates of opiate- and cocaine-free urine screens during treatment or at follow-up. Over the course of treatment, drug use, drug-related problems, and HIV risk behaviours decreased significantly for patients assigned to both treatment intensities. Improvements were maintained at follow-up. Patients in the day treatment programme were significantly more satisfied with two of the eight programme dimensions: employment counselling, (p=0.005) and leisure time activities, (p=0.01). The two groups were not different in terms of the other six dimensions. Patients with no prior history of methadone maintenance were more likely to be abstinent at follow-up if they had received the lower-intensity intervention.
The study found that an intensive day treatment programme yielded no greater benefit with respect to drug abstinence initiation and maintenance, resolution of drug-related problems, or reduction of HIV risk behaviours than a lower-intensity intervention. Although patient satisfaction ratings after treatment tended to be higher for the day treatment programme than for enhanced standard care, there was no evidence from the post hoc matching analysis that assignment to treatment intensity on the basis of patient preference at entry into treatment would have changed the clinical outcome. The study data provide some evidence for the interpretation that more treatment may even be counter-therapeutic for certain of subgroups of patients.
Measure of benefits used in the economic analysis
No summary benefit measure was identified in the economic analysis, and only individual clinical outcomes were reported. Based on the overall equivalence of the two alternatives in terms of the clinical outcome measures, the economic study appears to have proceeded on the basis of cost-minimisation analysis.
Costs were not discounted due to the short time frame of the cost analysis (less than 2 years). Resource use profiles were reported separately from the costs. Cost breakdown was reported separately. The cost analysis covered the programme costs (including methadone, urine screens, medical care, counselling, group therapy, and other related expenses), and secondary costs (including off-site health care, criminal justice, vocational and legal services, and the administrative cost of transfer payments). The perspective adopted in the cost analysis appears to have been that of society. The costs were calculated in terms of treatment completers only. The unit costs of programme services included salaries, fringe benefits, and overheads. Programme costs and secondary costs were grouped separately because primary cost and utilisation data were based on internal accounting documents and attendance records, whereas the secondary cost data were derived from national cost averages and patients' self-reports. The price year was 1995.
Statistical analysis of costs
Cost comparisons were based on using Student's t tests, with the alpha level set at less than 0.02 after Bonferroni correction.
Indirect costs were not discounted due to the short time frame of the cost analysis. Some information was provided regarding the employment status of the participants at treatment completion. Productivity from earnings was based on the Addiction Severity Index data as a negative cost. The perspective adopted in the cost analysis appears to have been that of the society. The price year was 1995.
No sensitivity analysis was conducted.
Estimated benefits used in the economic analysis
The mean (SD) total programme cost was $4,965 ($1,068) in the patients receiving the day treatment programme versus $1,600 ($406), (p<0.001; mean difference = $3,364; 95% CI: $3,157 - $3,572). The mean (SD) total costs for 12 weeks were $6,365 ($2,161) for day treatment and $2,339 ($2,199) for enhanced standard care, (p<0.001; mean difference = $4,026; 95% CI: $3,468 - $4,583).
Synthesis of costs and benefits
Costs and benefits were not combined since the economic study was reduced to a cost-minimisation analysis.
Providing an intensive day treatment programme to unemployed, inner-city methadone patients was not cost-effective relative to a programme of enhanced methadone maintenance services, which produced comparable outcomes at less than half the cost.
CRD COMMENTARY - Selection of comparators
A justification was given for the choice of the comparator. The enhanced standard methadone maintenance treatment programme was previously shown to be superior to standard care. It was noted that the current study compared two active, effective treatments. You, as a database user, should consider whether this is a relevant health technology in your own setting.
Validity of estimate of measure of effectiveness
The internal validity of the effectiveness results is likely to be high due to the randomised nature of the study design, the study's high (albeit, retrospectively calculated) power to detect clinically significant difference between the groups, and the use of an objective measure of drug use. The comparability of the two study groups in terms of the baseline characteristics appears not to have been addressed. It was only reported that those who completed treatment did not differ from the treatment dropouts in terms of baseline demographic and clinical characteristics. Furthermore, the effectiveness analysis appears to have been based on treatment completers only rather than on intention to treat. The study sample appears to have been representative of a broad range of patients from a community-based methadone maintenance programme.
Validity of estimate of measure of benefit
The analysis of benefits was based upon the therapeutic equivalence of treatment alternatives. The economic analysis therefore included only costs.
Validity of estimate of costs
Positive aspects of the cost analysis which are likely to have enhanced its validity, were that resource use quantities were reported separately from the costs, cost categories were reported separately and the price year was specified. Furthermore, statistical analyses were performed on resource use and cost data, the cost data appear to have been based on actual costs rather than charges and the effects of alternative procedures on indirect costs were addressed. However, the following features may have adversely affected the validity. The cost analysis was performed on a retrospective basis and was conducted on the basis of treatment completers only rather than on intention to treat. In addition, secondary and productivity cost data were not gathered systematically from the same patient sample as that used in the effectiveness analysis. Cost results may not be generalisable outside the study setting.
The authors' conclusions appear to be justified given the uncertainties in the data. The issue of generalisability to other settings or countries was partially addressed by comparing the results of this study with another Veterans Affairs-based methadone study. Further comparisons were made with relevant studies. The degree to which the study sample was representative of the study population was partially discussed in comparisons made with other studies.
Implications of the study
Whether less treatment is even more cost-effective in a community-based clinic, as was found with a Veterans Affairs (VA) sample, awaits further investigation. It may also be important to include societal costs of different levels of service in methadone programmes in future studies, as the authors attempted to do in the current study, because these may interact in complex ways with on-site methadone programme costs. Further research is needed to investigate which components (such as group or individual counselling, and on- or off-site referral resources) contribute to the effectiveness of enhanced methadone services.
Source of funding
Supported by National Institute on Drug abuse grants (DA-08754 and DA-00277 (to Dr Avants), DA-00112 (to Dr Kosten), and DA-00089 (to Dr Rounsaville).
Avants S K, Margolin A, Sindelar J L, Rounsaville B J, Schottenfeld R, Stine S, Cooney N L, Rosenheck R A, Li S H, Kosten T R. Day treatment versus enhanced standard methadone services for opioid-dependent patients: a comparison of clinical efficacy and cost. American Journal of Psychiatry 1999; 156(1): 27-33
Other publications of related interest
McLellan A T, Arndt I O, Metzger D S, Woody G E, O'Brien C P. The effects of psychosocial services in substance abuse treatment. JAMA 1993;269:1953-1959.
Subject indexing assigned by NLM
Adult; Cocaine-Related Disorders /economics /epidemiology /therapy; Cost-Benefit Analysis; Day Care, Medical /economics; Female; Follow-Up Studies; HIV Infections /epidemiology; Health Care Costs; Humans; Male; Methadone /economics /therapeutic use; Opioid-Related Disorders /economics /epidemiology /rehabilitation; Outcome Assessment (Health Care); Risk-Taking; Severity of Illness Index; Substance Abuse Detection; Substance Abuse Treatment Centers /economics; Treatment Outcome
Date bibliographic record published
Date abstract record published