Same-visit hepatitis C testing and treatment to accelerate cure among people who inject drugs (the QuickStart Study): a cluster randomised cross-over trial protocol.

INTRODUCTION: Despite universal access to government-funded direct-acting antivirals (DAAs) in 2016, the rate of hepatitis C treatment uptake in Australia has declined substantially. Most hepatitis C is related to injecting drug use; reducing the hepatitis C burden among people who inject drugs (PWID) is, therefore, paramount to reach hepatitis C elimination targets. Increasing DAA uptake by PWID is important for interrupting transmission and reducing incidence, as well as reducing morbidity and mortality and improving quality of life of PWID and meeting Australia's hepatitis C elimination targets. METHODS AND ANALYSIS: A cluster randomised cross-over trial will be conducted with three intervention arms and a control arm. Arm A will receive rapid hepatitis C virus (HCV) antibody testing; arm B will receive rapid HCV antibody and rapid RNA testing; arm C will receive rapid HCV antibody testing and same-day treatment initiation for HCV antibody-positive participants; the control arm will receive standard of care. The primary outcomes will be (a) the proportion of participants with HCV commencing treatment and (b) the proportion of participants with HCV achieving cure. Analyses will be conducted on an intention-to-treat basis with mixed-effects logistic regression models. ETHICS AND DISSEMINATION: The study has been approved by the Alfred Ethics Committee (number HREC/64731/Alfred-2020-217547). Each participant will provide written informed consent. Reportable adverse events will be reported to the reviewing ethics committee. The findings will be presented at scientific conferences and published in peer-reviewed journals. TRIAL REGISTRATION NUMBER: NCT05016609. TRIAL PROGRESSION: The study commenced recruitment on 9 March 2022 and is expected to complete recruitment in December 2024.

Viral hepatitis testing and treatment in community pharmacies: a systematic review and meta-analysis.

Background: The World Health Organization seeks to eliminate viral hepatitis as a public health threat by 2030. This review and meta-analysis aims to evaluate the effectiveness of programs for hepatitis B and C testing and treatment in community pharmacies. Methods: Medline, Embase, Cochrane CENTRAL, and Global Health were searched from database inception until 12 November 2023. Comparative and single arm intervention studies were eligible for inclusion if they assessed delivery of any of the following interventions for hepatitis B or C in pharmacies: (1) pre-testing risk assessment, (2) testing, (3) pre-treatment assessment or (4) treatment. Primary outcomes were proportions testing positive and reaching each stage in the cascade. Random effects meta-analysis was used to estimate pooled proportions stratified by recruitment strategy and setting where possible; other results were synthesised narratively. This study was pre-registered (PROSPERO: CRD42022324218). Findings: Twenty-seven studies (4 comparative, 23 single arm) were included, of which 26 reported hepatitis C outcomes and four reported hepatitis B outcomes. History of injecting drug use was the most identified risk factor from pre-testing risk assessments. The pooled proportion hepatitis C antibody positive from of 19 studies testing 5096 participants was 16.6% (95% CI 11.0%-23.0%; heterogeneity I2 = 96.6%). The pooled proportion antibody positive was significantly higher when testing targeted people with specified risk factors (32.5%, 95% CI 24.8%-40.6%; heterogeneity I2 = 82.4%) compared with non-targeted or other recruitment methods 4.0% (95% CI 2.1%-6.5%; heterogeneity I2 = 83.5%). Meta-analysis of 14 studies with 813 participants eligible for pre-treatment assessment showed pooled attendance rates were significantly higher in pharmacies (92.7%, 95% CI 79.1%-99.9%; heterogeneity I2 = 72.4%) compared with referral to non-pharmacy settings (53.5%, 95% CI 36.5%-70.1%; heterogeneity I2 = 92.3%). The pooled proportion initiating treatment was 85.6% (95% CI 74.8%-94.3%; heterogeneity I2 = 75.1%). This did not differ significantly between pharmacy and non-pharmacy settings. Interpretation: These findings add pharmacies to the growing evidence supporting community-based testing and treatment for hepatitis C. Few comparative studies and high degrees of statistical heterogeneity were important limitations. Hepatitis B care in pharmacies presents an opportunity for future research. Funding: None.

Predictors of COVID-19 vaccine uptake among people who use substances: a case study in Tehran.

BACKGROUND: Vaccination is one of the most effective ways to manage infectious disease epidemics such as Covid-19. However, the low rates of vaccination in populations at risk including people using illicit substances, hinders the effectiveness of preventive vaccines in reducing transmission. The aim of this study was to investigate the rate of Covid-19 vaccination and its related factors among people who use substances in Tehran, Iran. METHODS: Between July and December 2022, 386 people who use substances aged ≥ 18 years old were recruited by convenience street-based sampling in Tehran. The outcome variable in this study was self-reported completion of at least two doses of the Covid-19 vaccine. Logistic regression was used to investigate the factors related to Covid-19 vaccination. Data were analyzed using SPSS software version 20 at the 0.05 level of significance. As a measure of risk, 95% Confidence interval (CI) was used. The level of significance was considered at 0.05. RESULTS: Almost three-quarters (n = 286) of the participants reported receiving at least two doses of the Covid-19 vaccine (95% CI, 70.2-79.3). Those participants with high school diplomas were 1.17 times more likely than less educated participants to report having had 2 vaccinations (OR of 1.17, CI 95%: 1.03-1.81). Participants with a higher mean score of having a positive attitude towards Covid-19 vaccination were more likely to have received a vaccination (OR of 1.12, CI 95%: 1.08-1.17). Ethnicity was also an influential variable, people with non-Fars ethnicity were less likely to be vaccinated than those of Fars ethnicity (OR of 0.33, CI 95%: 0.13-0.81). People with higher-than-average monthly income were more likely to report vaccination than those with low monthly incomes (OR of 1.27, CI 95%: 1.09-1.8). Also, participants reporting less access to vaccination centers had a lower chance of reporting having been vaccinated than those who reported high access to vaccination centers (OR of .17, CI 95%: .08-.36). CONCLUSIONS: Covid-19 vaccine uptake was found to be relatively high among people using illicit substances in this study. Higher levels of education, Fars ethnicity, higher income levels, having a positive attitude towards vaccination and access to vaccination centers were the most important predictors of Covid-19 vaccination in this study.

Barriers and Enablers of Diabetes Self-Management Strategies Among Arabic-Speaking Immigrants Living with Type 2 Diabetes in High-Income Western countries- A Systematic Review.

The aim of this review is to investigate barriers and enablers of diabetes self-management strategies among migrant Arabic-speaking background [ASB] individuals living with type 2 diabetes in high-income Western countries. Despite living in high-income Western countries, individuals from ASB are perceived to have difficulties adopting self-management strategies and this necessitates gaining an understanding of factors that may impact the uptake of these strategies. Ten studies are included in this review: five quantitative and five qualitative. Quality assessment was conducted using the Joanna Briggs Institute Critical Appraisal and Hawker tools. The findings of the quantitative studies were descriptively analysed, while thematic analysis was performed for the qualitative studies. The results indicate that individuals from ASB are perceived to have low levels of adherence to diabetes self-management. It is also suggested that participants who did not complete high school have poorer glycaemic control compared to those with a high school qualification (30 vs. 16%). Regular exercise was reported to be less likely to be adopted by ASBs homemakers, and those who were unemployed, by 82% and 70%, respectively, compared to those employed (homemakers: OR = 0.187, P = 0.006; 95% CI = 056-0.620), (unemployed OR = 0.30, P = 0.046; 95% CI = 0.093-0.980). Cultural, social, religious beliefs, lack of knowledge and language barriers are some of the factors identified that impact self-management among ASB individuals. It is suggested that diabetes self-management education program (DSME) tailored to ASB immigrants culture may be an effective way to encourage them to uptake self-management strategies.

Epidemiology of acute infections in people who inject drugs in Australia.

ISSUES: People who inject drugs are at risk of acute infections, such as skin and soft tissue infections, infective endocarditis, bone and joint infections and bloodstream infections. There has been an increase in these infections in people who inject drugs internationally over the past 10 years. However, the local data regarding acute infections in Australia has not been well described. APPROACH: We review the epidemiology of acute infections and associated morbidity and mortality amongst people who inject drugs in Australia. We summarise risk factors for these infections, including the concurrent social and psychological determinants of health. KEY FINDINGS: The proportion of people who report having injected drugs in the prior 12 months in Australia has decreased over the past 18 years. However, there has been an increase in the burden of acute infections in this population. This increase is driven largely by skin and soft tissue infections. People who inject drugs often have multiple conflicting priorities that can delay engagement in care. IMPLICATIONS: Acute infections in people who inject drugs are associated with significant morbidity and mortality. Acute infections contribute to significant bed days, surgical requirements and health-care costs in Australia. The increase in these infections is likely due to a complex interplay of microbiological, individual, social and environmental factors. CONCLUSION: Acute infections in people who inject drugs in Australia represent a significant burden to both patients and health-care systems. Flexible health-care models, such as low-threshold wound clinics, would help directly target, and address early interventions, for these infections.

Distribution of rapid HCV antibody self-test kits via needle/syringe dispensing machines: Implementation and evaluation of the Vend-C pilot study in Melbourne, Australia.

Recent guidance from the World Health Organization strongly recommended hepatitis C virus (HCV) self-testing. We implemented the Vend-C pilot study to explore the effectiveness and feasibility of distributing rapid HCV antibody self-test kits to people who inject drugs via needle/syringe dispensing machines (SDMs). Over a 51-day study period between August and September 2022, we distributed HCV antibody self-test kits via two SDMs. During the study period, 63 self-test kits were dispensed, averaging 1.2 self-test kits per day. Our access methods for evaluation questionnaires failed to attract participants (n = 4). We implemented the Vend-C pilot study in direct response to recent WHO recommendations. While self-test kits were effectively distributed from the two SDMs, our evaluation methodology failed. Consequently, we cannot determine the success of linkage to care. Even so, with HCV treatment numbers dropping in Australia, innovative engagement solutions are needed, and considering the number of self-test kits provided in our pilot, the model could have an important future place in HCV elimination efforts.

Prevalence and incidence of emergency department presentations and hospital separations with injecting-related infections in a longitudinal cohort of people who inject drugs.

People who inject drugs are at risk of acute bacterial and fungal injecting-related infections. There is evidence that incidence of hospitalizations for injecting-related infections are increasing in several countries, but little is known at an individual level. We aimed to examine injecting-related infections in a linked longitudinal cohort of people who inject drugs in Melbourne, Australia. A retrospective descriptive analysis was conducted to estimate the prevalence and incidence of injecting-related infections using administrative emergency department and hospital separation datasets linked to the SuperMIX cohort, from 2008 to 2018. Over the study period, 33% (95%CI: 31-36%) of participants presented to emergency department with any injecting-related infections and 27% (95%CI: 25-30%) were admitted to hospital. Of 1,044 emergency department presentations and 740 hospital separations, skin and soft tissue infections were most common, 88% and 76%, respectively. From 2008 to 2018, there was a substantial increase in emergency department presentations and hospital separations with any injecting-related infections, 48 to 135 per 1,000 person-years, and 18 to 102 per 1,000 person-years, respectively. The results emphasize that injecting-related infections are increasing, and that new models of care are needed to help prevent and facilitate early detection of superficial infection to avoid potentially life-threatening severe infections.

Life-time HIV testing among people who inject drugs in Iran: results from the National Rapid Assessment and Response survey.

Background: HIV testing is recommended for people who inject drugs (PWID). The aim of this study was to determine the prevalence of lifetime HIV testing among PWID and to better understand the predictors for HIV testing in a convenience sample across Iran. Materials and methods: This study is a secondary analysis of Iran's National Rapid Assessment and Response survey conducted between October 2016 and March 2017. Analysis includes the 999 people who reported injecting drugs across the capital cities of 21 provinces. Data were collected by using the venue-based application of the Time Location Sampling (TLS) frame. Chi-square tests were used to examine the difference between HIV testing across different quantitative variables. Logistic regression was used to determine the predictors of life-time HIV testing. Analysis was performed using STATA V.12 software with a significance level of 95%. Results: Most participants were male (n = 902, 93.50%), and over half (n = 555, 59.17%) were older than 35 years old. About one-third, (n = 326, 38%) of people interviewed were single and another one-third (n = 251, 29%) reported being divorced. Over two-thirds of participants (n = 678, 69.78%) in this study reported lifetime HIV testing. The results from a multiple variable logistic regression showed people with a university education were more likely to have been previously tested for HIV than illiterate people (OR = 18.87, 95%CI 2.85-124.6, value of p = 0.002). Those individuals who reported ever receiving methadone treatment were 2.8 times more likely to have been tested for HIV than individuals without methadone treatment experience (OR = 2.89, 95%CI 1.53-5.42, value of p < 0.001). Needle syringe sharing in last month, was negatively associated with life-time HIV testing (OR = 0.29, 95%CI 0.17-0.48, value of p < 0.001). Conclusion: Despite Iran's wide availability and access to counseling services for HIV testing in key populations, the proportion of PWID being tested for HIV could be improved. Developing effective strategies to increase people's understanding and awareness of the importance of and need for HIV prevention and familiarity with HIV testing sites is an essential step in increasing HIV testing for this population. Studies on more recent HIV testing are required to better assess and understand the frequency of HIV testing among PWID in Iran.

Injection Drug Use Frequency Before and After Take-Home Naloxone Training.

Importance: Concerns that take-home naloxone (THN) training may lead to riskier drug use (as a form of overdose risk compensation) remain a substantial barrier to training implementation. However, there was limited good-quality evidence in a systematic review of the association between THN access and subsequent risk compensation behaviors. Objective: To assess whether THN training is associated with changes in overdose risk behaviors, indexed through injecting frequency, in a cohort of people who inject drugs. Design, Setting, and Participants: This cohort study used prospectively collected self-reported behavioral data before and after THN training of participants in The Melbourne Injecting Drug User Cohort Study (SuperMIX). Annual interviews were conducted in and around Melbourne, Victoria, Australia, from 2008 to 2021. SuperMIX participants were adults who regularly injected heroin or methamphetamine in the 6 months preceding their baseline interview. The current study included only people who inject drugs who reported THN training and had participated in at least 1 interview before THN training. Exposure: In 2017, the SuperMIX baseline or follow-up survey began asking participants if and when they had received THN training. The first THN training date that was recorded was included as the exposure variable. Subsequent participant interviews were excluded from analysis. Main Outcomes and Measures: Injecting frequency was the primary outcome and was used as an indicator of overdose risk. Secondary outcomes were opioid injecting frequency, benzodiazepine use frequency, and the proportion of the time drugs were used alone. Fixed-effects generalized linear (Poisson) multilevel modeling was used to estimate the association between THN training and the primary and secondary outcomes. Time-varying covariates included housing status, income, time in study, recent opioid overdose, recent drug treatment, and needle and syringe coverage. Findings were expressed as incidence rate ratios (IRRs) with 95% CIs. Results: There were 1328 participants (mean [SD] age, 32.4 [9.0] years; 893 men [67.2%]) who completed a baseline interview in the SuperMIX cohort, and 965 participants completed either a baseline or follow-up interview in or after 2017. Of these 965 participants, 390 (40.4%) reported THN training. A total of 189 people who inject drugs had pretraining participant interviews with data on injecting frequency and were included in the final analysis (mean [SD] number of interviews over the study period, 6.2 [2.2]). In fixed-effects regression analyses adjusted for covariates, there was no change in the frequency of injecting (IRR, 0.91; 95% CI, 0.69-1.20; P = .51), opioid injecting (IRR, 0.95; 95% CI, 0.74-1.23; P = .71), benzodiazepine use (IRR, 0.96; 95% CI, 0.69-1.33; P = .80), or the proportion of reported time of using drugs alone (IRR, 1.04; 95% CI, 0.86-1.26; P = .67) before and after THN training. Conclusions and Relevance: This cohort study of people who inject drugs found no evidence of an increase in injecting frequency, along with other markers of overdose risk, after THN training and supply. The findings suggest that THN training should not be withheld because of concerns about risk compensation and that advocacy for availability and uptake of THN is required to address unprecedented opioid-associated mortality.

The eliminate hepatitis C (EC) experience study: baseline characteristics of a cohort of people who inject drugs in Melbourne, Australia.

OBJECTIVES: Direct-acting antivirals provide an opportunity to eliminate hepatitis C virus (HCV) as a public health threat in Australia, yet barriers to care remain. In this study, we use baseline data from a longitudinal cohort of people who inject drugs to understand differences in participant characteristics and explore experiences of stigma, health service utilisation and health literacy between three care cascade groups. DESIGN: Cross-sectional. SETTING: Community and private primary healthcare services in Melbourne, Australia. PARTICIPANTS: Participants completed baseline surveys between 19 September 2018 and 15 December 2020. We recruited 288 participants; the median age was 42 years (IQR: 37-49 years) and 198 (69%) were male. At baseline, 103 (36%) self-reported being 'not engaged in testing', 127 (44%) had HCV RNA positivity but were 'not engaged in treatment' and 58 (20%) were 'engaged in HCV treatment'. OUTCOME MEASURES: Descriptive statistics were used to present the baseline demographics, health service utilisation and experiences of stigma data. We explored differences in these scales between participant demographics using χ2 test or fisher's exact tests, and differences between health literacy scores using one-way analysis of variance tests. RESULTS: A majority were in regular contact with multiple health services, and most had previously been identified as at-risk of HCV. In the 12 months preceding baseline, 70% reported any experiences of stigma related to injecting drug use. Assessment of health literacy data identified gaps for those 'not engaged in testing' and 'not engaged in treatment' across two relevant domains: 'ability to appraise health information' and 'ability to actively engage with healthcare providers'. CONCLUSION: In eliminate hepatitis C experience, lower HCV testing and treatment may be explained by experiences of stigmatisation or gaps in health literacy. Enhanced interventions targeting people who inject drugs to promote HCV care are needed.

Using 17th century medication for modern diabetes management: Doctors' perceptions of self-medication practices - A qualitative study.

Purpose: This study was conducted to explore doctors' perceptions and understanding of the self-medication practices of people living with type 2 diabetes. Methods: A qualitative research design incorporating 20 semi-structured, face-to-face interviews were conducted with doctors treating people with type 2 diabetes in Mysuru, India, between July 2019 and January 2020. All the interviews were conducted in doctors' clinics, audio-recorded and thematically analyzed. Results: Three themes were identified from these interviews- i) Doctors' beliefs towards their patients' use of traditional medicine and environmental factors influencing prescription practices, ii) Doctors reported little faith in traditional medicines, iii) Limited strategies implemented by doctors to overcome barriers to self-medications. Doctors reported greater belief in western medications over traditional medications and expressed concern that their patients favored traditional medications over western. Multiple factors such as social media, accessibility of healthcare facilities and pill burden influenced adherence to western medications. Also, lack of knowledge about traditional medications and trust in western medications available under government schemes have influenced prescription practices among doctors. It appears that doctors implemented strategies such as educating patients on the detrimental effects of self-medication and insisting on patients to take only western medications to achieve desired blood glucose levels when managing self-medication practices among people with diabetes. Conclusion: These results suggest that doctors have limited strategies to implement to prevent self-medication practices among people with diabetes. Increasing knowledge amongst doctors about JAS medication effectiveness and thereby garnering greater trust in generic medications. In addition, efforts should be made to identify the best ways to integrate traditional and western medicine into patient-centered care delivery. Supplementary Information: The online version contains supplementary material available at 10.1007/s40200-022-01154-5.

Perceived access to opioid agonist treatment in prison among people with a history of injection drug use: A qualitative study.

INTRODUCTION: Opioid agonist treatment (OAT) is associated with a reduced likelihood of hepatitis C incidence, nonfatal overdose, and (re)incarceration among people who inject drugs (PWID), yet factors underpinning decisions to access OAT in prison and postrelease are not well understood. The aim of the qualitative study was to explore the perspectives of OAT access while in prison among PWID recently released from prison in Australia. METHODS: Eligible participants enrolled in the SuperMix cohort (n = 1303) were invited to take part in a semi-structured interview in Victoria, Australia. Inclusion criteria were informed consent, aged ≥18 years, history of injection drug use, incarcerated for ≥3 months, and released from custody <12 months. The study team analysed data via a candidacy framework to account for macro-structural influences. RESULTS: Among 48 participants (33 male; ten Aboriginal), most injected drugs in the prior month (n = 41) with heroin the most frequently injected (n = 33) and nearly half (n = 23) were currently on OAT (primarily methadone). Most participants described the navigation and permeability of OAT services in prison as convoluted. If not on OAT pre-entry, prison policies often restricted access, leaving participants to withdraw in cells. In turn, some participants commenced OAT postrelease to ensure OAT continuity of care if reincarcerated. Other participants who experienced delayed access to OAT in prison stated no need to initiate while in prison or postrelease as they were now "clean". Last, implementation of OAT delivery in prison (e.g., lack of confidentiality) frequently led to changes in OAT type to avoid peer violence (pressure to divert OAT). CONCLUSION: Findings draw attention to simplistic notions of OAT accessibility in prisons, illuminating how structural determinants influence choice in PWID decision-making. Suboptimal access and acceptability of OAT delivery in prisons will continue to place PWID at risk of harm postrelease (e.g., overdose).

Epidemiology and Management of invasive infections among people who Use drugs (EMU): protocol for a prospective, multicentre cohort study.

INTRODUCTION: People who inject drugs (PWID) are at risk of invasive infections such as bloodstream infections, endocarditis, osteomyelitis and septic arthritis. Such infections require prolonged antibiotic therapy, but there is limited evidence about the optimal care model to deliver to this population. The Epidemiology and Management of invasive infections among people who Use drugs (EMU) study aims to (1) describe the current burden, clinical spectrum, management and outcomes of invasive infections in PWID; (2) determine the impact of currently available models of care on completion of planned antimicrobials for PWID admitted to hospital with invasive infections and (3) determine postdischarge outcomes of PWID admitted with invasive infections at 30 and 90 days. METHODS AND ANALYSIS: EMU is a prospective multicentre cohort study of Australian public hospitals who provide care to PWIDs with invasive infections. All patients who have injected drugs in the previous six months and are admitted to a participating site for management of an invasive infection are eligible. EMU has two components: (1) EMU-Audit will collect information from medical records, including demographics, clinical presentation, management and outcomes; (2) EMU-Cohort will augment this with interviews at baseline, 30 and 90 days post-discharge, and data linkage examining readmission rates and mortality. The primary exposure is antimicrobial treatment modality, categorised as inpatient intravenous antimicrobials, outpatient antimicrobial therapy, early oral antibiotics or lipoglycopeptide. The primary outcome is confirmed completion of planned antimicrobials. We aim to recruit 146 participants over a 2-year period. ETHICS AND DISSEMINATION: EMU has been approved by the Alfred Hospital Human Research Ethics Committee (Project number 78815.) EMU-Audit will collect non-identifiable data with a waiver of consent. EMU-Cohort will collect identifiable data with informed consent. Findings will be presented at scientific conferences and disseminated by peer-review publications. TRIAL REGISTRATION NUMBER: ACTRN12622001173785; Pre-results.

Stigma Associated with Alcohol and Other Drug Use Among People from Migrant and Ethnic Minority Groups: Results from a Systematic Review of Qualitative Studies.

Stigma reduces access to alcohol and other drug (AOD) support. This systematic review explored perceptions and experiences of stigma associated with AOD use among migrant and ethnic minority groups. Qualitative studies published in English were identified using six databases. Two reviewers screened and critically appraised articles using the Joanna Briggs Institute Critical Appraisal Checklist for qualitative studies. Data were synthesised using best fit framework synthesis. Twenty-three studies were included. Stigma drivers and facilitators included stereotypes, socio-cultural norms, legal responses and precarious lived experiences. Stigma intersected with gender, citizenship, race and ethnicity and manifested though shame, exclusion, secondary stigma and discrimination in treatment. Outcomes and impacts included avoidance of services, emotional distress, isolation and loneliness. This review identified similar stigma experiences to other populations, however outcomes were complicated by precarious lived experiences and multiple stigmatised identities. Multi-level interventions are required to reduce AOD-related stigma for migrant and ethnic minority groups.

Diagnostic accuracy for self-reported methamphetamine use versus oral fluid test as the reference standard in a methamphetamine-dependent intervention trial population.

AIMS: Treatment of methamphetamine dependence requires monitoring of recent use or abstinence. Self-report is commonly used for routine monitoring, but the accuracy of self-report is not established. For the treating clinician, the key accuracy statistic is the negative predictive value (NPV). The study aim was to estimate the NPV of self-reported non-use of methamphetamine compared with an oral fluid reference standard. DESIGN, SETTING AND PARTICIPANTS: This study was a secondary (subgroup) analysis from a randomized controlled pharmacotherapy trial. Three Australian outpatient addiction services took part. Particpants were 139 people dependent on methamphetamine. MEASUREMENTS: Weekly oral fluid samples over 12 weeks to determine methamphetamine (and amphetamine) concentrations were used as the reference standard. Self-report of any methamphetamine use in the previous 7 days by the time-line follow-back method was the index test. Standard diagnostic accuracy statistics were calculated for all available paired episodes (n = 1134). Three NPV values were calculated: unadjusted NPV and NPV adjusted for clustering of observations through logistic regression and generalized estimating equation (GEE). We also calculated the NPVs for a range of prevalence rates of methamphetamine use, for the calculated levels of sensitivity and specificity. FINDINGS: Sensitivity was 96.4% [95% confidence interval (CI) = 95-97.5], specificity was 63.7% (95% CI = 57.3-69.8) and positive predictive value (PPV) was 90.8% (95% CI = 88.8-92.6). The unadjusted NPV was 82.7% (95% CI = 76.5-87.9), adjusted NPV by logistic regression 82.7% (95% CI = 73.9-91.5) and GEE 76.8% (95% CI = 66.8-86.8). At a methamphetamine use prevalence of 5%, the estimated NPV would be 99.7% (95% CI = 99.6-99.9) and at 95% prevalence, 48.2% (95% CI = 39.6-57.0). CONCLUSIONS: Self-report of no recent methamphetamine use appears to be sufficiently accurate to be clinically useful at the expected prevalence rates of methamphetamine use in clinical treatment settings. If generalizable to clinical settings, where these tests are routinely conducted, this may permit a reduction in the frequency and cost of oral fluid assays.