A multilevel analysis of regional and individual effects on methadone maintenance treatment in Taiwan

Risk of motor vehicle collisions after methadone use: A systematic review and meta-analysis

INTRODUCTION

Methadone maintenance therapy is a leading treatment strategy for stabilizing and rehabilitating patients with opioid dependence; however, findings related to the risk of motor vehicle collisions after methadone use have been conflicting. In the present study, we compiled the available evidence on the risk of motor vehicle collisions after methadone use.

METHODS

We completed a systematic review and meta-analysis of studies identified on six databases. Two reviewers independently screened the identified epidemiological studies, extracted data, and used the Newcastle-Ottawa Scale to assess the quality of the studies. Risk ratios were retrieved for analysis, conducted using random-effects model. Sensitivity analyses, subgroup analyses, and tests for publication bias were conducted.

RESULTS

Among 1446 identified relevant studies, a total of 7 epidemiological studies enrolling 33226142 participants met the inclusion criteria. Overall, study participants with methadone use had a higher risk of motor vehicle collisions than did those without methadone use (pooled relative risk 1.92, 95% CI 1.25-2.95; number needed to harm 11.3, 95% CI 5.3-41.6); the I² statistic was 95.1%, indicating substantial heterogeneity. Subgroup analyses revealed that database type explained 95.36% of the between-study variance (p = 0.008). Egger's (p = 0.376) and Begg's (p = 0.293) tests revealed no evidence of publication bias. Sensitivity analyses indicated that the pooled results were robust.

CONCLUSION

The present review revealed that methadone use is significantly associated with a nearly doubled risk of motor vehicle collisions. Therefore, clinicians should exercise caution in implementing methadone maintenance therapy for drivers.

Risk of motor vehicle collisions after methadone use

Methadone maintenance treatment (MMT) can alleviate opioid dependence. However, MMT possibly increases the risk of motor vehicle collisions. The current study investigated preliminary estimation of motor vehicle collision incidence rates. Furthermore, in this population-based retrospective cohort study with frequency-matched controls, opiate adults receiving MMT (cases) and those not receiving MMT (controls) were identified at a 1:2 ratio by linking data from several nationwide administrative registry databases. From 2009 to 2016, the crude incidence rate of motor vehicle collisions was the lowest in the general adult population, followed by that in opiate adults, and it was the highest in adults receiving MMT. The incidence rates of motor vehicle collisions were significantly higher in opiate users receiving MMT than in those not receiving MMT. Kaplan–Meier curves of the incidence of motor vehicle collisions differed significantly between groups, with a significant increased risk during the first 90 days of follow-up. In conclusion, drivers receiving MMT have higher motor vehicle collision risk than those not receiving MMT in opiate users, and it is worthy of noticing road safety in such drivers, particularly during the first 90 days of MMT.

In 2019, 58 million people were estimated to use opioids – a group of substances that include drugs like heroin and morphine. Dependence on opioids can be managed using a prescribed dose of an opioid called methadone, which is administered through a controlled treatment plan. This so-called methadone maintenance treatment manages withdrawal symptoms in opioid-dependent individuals and can reduce the occurrences of overdose, criminal activity and transmission of diseases such as HIV.

However, methadone acts on the same brain receptors as other opioids, and individuals receiving methadone may experience impaired motoric and cognitive functioning, including reduced driving ability. It is therefore important to know whether methadone maintenance treatment may increase an individual’s risk to cause road accidents.

To assess motor vehicle collision risk associated with individuals receiving methadone maintenance treatment, Yang et al. analysed data from the Taiwan National Health Insurance Research Database and six Taiwanese administrative registries, including the ministries of health and welfare, interior and justice, and registries in substitution maintenance therapy, road accidents and the National Police Agency.

Initial analyses found that individuals receiving treatment had a higher risk to be involved in car accidents than the general adult population or those without methadone maintenance treatment. Further tests showed that individuals receiving treatment were at three times higher risk of collisions than individuals not receiving treatment, particularly in the first 90 days.

These findings may help individuals undergoing methadone maintenance treatment manage their risk of motor vehicle collisions. Further investigation is needed to reveal the underlying mechanisms of methadone-related impairment of driving ability.

Negative Impacts of Self-Stigma on the Quality of Life of Patients in Methadone Maintenance Treatment: The Mediated Roles of Psychological Distress and Social Functioning

A sample of heroin users (n = 250) in methadone maintenance treatment (MMT) was used in this cross-sectional study to clarify the mechanisms of the effects of stigma on quality of life (QoL) through psychological distress and social functioning. All the participants had their self-stigma, psychological distress, social functioning, and QoL measured. Psychological distress and social functioning were proposed to be mediators between self-stigma and QoL. Several linear models using structural equation modeling were conducted to examine the mediated effects. The negative effects of self-stigma on QoL were significantly mediated by psychological distress, as self-stigma directly and significantly influenced psychological distress, but not social functioning. This study demonstrated a linear model describing the effects of self-stigma on QoL for opioid-dependent individuals; psychological distress was also an important mediator between self-stigma and their QoL. Clinicians were able to notice the importance of reducing self-stigma for opioid-dependent individuals according to the following results: higher levels of self-stigma were associated with high psychological distress, decreased social functioning, and impaired QoL. Our mediation findings suggest that treating psychological distress is better than treating social functioning if we want to eliminate the effects of self-stigma on QoL for heroin users.

Psychological Distress is Correlated with Erectile Dysfunction Among Patients Receiving Methadone Maintenance in Taiwan

OBJECTIVE

Although erectile dysfunction (ED) is prevalent in patients receiving long-term methadone maintenance, studies in Chinese culture exploring the relationship between psychological distress and ED are scarce.

METHODS

One hundred eighty-seven male patients in methadone maintenance treatment were assessed in this cross-sectional study. Instruments included the Opiate Treatment Index (OTI) to evaluate the health-related consequences of methadone treatment and the Chinese Health Questionnaire-12 (CHQ-12) for the assessment of psychological distress, respectively. ED was defined by the International Index of Erectile Function 15. Quality of life was measured using the European Quality of Life-5 Dimensions. We constructed a multiple linear regression model to examine the associations between the determinants and ED.

RESULTS

The CHQ-12 score had a significant relationship with the severity of ED after controlling for all important variables. The social functioning domain of the OTI and methadone dose was also significantly correlated with ED.

CONCLUSIONS

The strong relationship between psychological distress and ED emphasized the importance of both diagnosis and management of ED among methadone patients receiving long-term maintenance treatment. The etiological relationship between methadone dose and ED require further investigation.

The reductions in monetary cost and gains in productivity with methadone maintenance treatment: one year follow-up

While methadone maintenance treatment (MMT) is beneficial for heroin dependence, there is little information regarding the reductions in monetary cost and gains in productivity following MMT. The aim of this study was to evaluate the changes in the monetary cost of heroin addiction and productivity after one year of MMT. Twenty-nine participants from an MMT clinic were included. The monetary cost, productivity, quality of life (QOL) and mental health status were assessed at both baseline and one year follow-up. The average annual total cost was approximately US$26,485 (1.43 GDP per capita in 2010) at baseline, and decreased by 59.3% to US$10,784 (0.58 GDP) at follow-up. The mean number of months of unemployment dropped from 6.03 to 2.79, the mean income increased to exceed the basic salary, but only reached 45.3% of the national average monthly earnings. The participants׳ mental health improved, but their QOL scores did not increase significantly. After one year of MMT, the monetary cost of heroin addiction fell, both the productivity and mental health of the participants׳ improved, but limited gains were seen with regard to their QOL.

Changes in quality of life (WHOQOL-BREF) and addiction severity index (ASI) among participants in opioid substitution treatment (OST) in low and middle income countries: an international systematic review

BACKGROUND

Opioid substitution treatment (OST) can increase quality of life (WHOQOL-BREF) and reduce addiction severity index (ASI) scores among participants over time. OST program participants have noted that improvement in quality of life is one of the most important variables to their reduction in drug use. However, there is little systematic understanding of WHOQOL-BREF and ASI domain changes among OST participants in low and middle-income countries (LMIC).

METHODS

Utilizing PRISMA guidelines we conducted a systematic literature search to identify OST program studies documenting changes in WHOQOL-BREF or ASI domains for participants in buprenorphine or methadone programs in LMIC. Standardized mean differences for baseline and follow-up domain scores were compared along with relationships between domain scores, OST dosage, and length of follow-up.

RESULTS

There were 13 OST program studies with 1801 participants from five countries eligible for inclusion in the review. Overall, statistically significant changes were noted in all four WHOQOL-BREF domain and four of the seven ASI domain scores (drug, psychological, legal, and family) documented in studies. Dosage of pharmacologic medication and length of follow-up did not affect changes in domain scores.

CONCLUSION

WHOQOL-BREF and ASI domain scoring is a useful tool in measuring overall quality of life and levels of addiction among OST participants. Coupled with measurements of blood-borne infection, drug use, relapse, and overdose, WHOQOL-BREF and ASI represent equally important tools for evaluating the effects of OST over time and should be further developed as integrated tools in the evaluation of participants in LMIC.

Retention of participants in medication-assisted programs in low- and middle-income countries: an international systematic review

BACKGROUND AND AIMS

Medication-assisted treatment (MAT) is a key component in overdose prevention, reducing illicit opiate use and risk of blood-borne virus infection. By retaining participants in MAT programs for longer periods of time, more noticeable and permanent changes in drug use, risk behavior and quality of life can be achieved. Many studies have documented retention in MAT programs in high-income countries, using a 50% average 12-month follow-up retention rate as a marker for a successful MAT program. This study contributes to a systematic understanding of how successful programs have been in retaining participants in low- and middle-income countries (LMIC) over time.

METHODS

Using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we conducted a systematic literature search to identify MAT program studies that documented changes in retention over time for participants in buprenorphine and methadone programs in LMIC. Retention was measured for participants by length of follow-up, type of MAT and treatment dosage.

RESULTS

There were 58 MAT program studies, with 27 047 participants eligible for inclusion in the review. Overall average retention after 12 months was 54.3% [95% confidence interval (CI) = 46.2, 63.7%]. Overall average retention was moderately good for both buprenorphine (48.3%, 95% CI = 22.1, 74.6%) and methadone (56.6%, 95% CI = 45.9%, 67.3%) after 12 months of treatment. Among programs using methadone there was no statistically significant difference in average retention by dosage level, and the 10 highest and lowest dosage programs obtained similar average retention levels after 12 months.

CONCLUSION

Medication-assisted treatment programs in low- and middle-income countries achieve an average 50% retention rate after 12 months, with wide variation across programs but little difference between those using buprenorphine versus methadone.