What's the agreement between self-reported and biochemical verification of drug use? A look at permanent supportive housing residents

Differentiating people who use cannabis heavily through latent class analysis

BACKGROUND

People who use cannabis daily or near-daily vary considerably in their daily dosage and use frequency, impacting both experienced effects and adverse consequences. This study identified heavy cannabis user groups according to consumption patterns and factors associated with class membership.

METHODS

We conducted a cross-sectional study of 380 Spanish residents (61.8% male; average age = 30.3 years) who had used cannabis ≥ 3 days/week throughout the past year. Participants were recruited through chain referral and cannabis social clubs. We applied latent class analysis (LCA) to cluster participants according to use intensity. LCA indicators included frequency of weekly cannabis use, joints smoked each day, cannabis dosage, and if cannabis was consumed throughout the day or only at specific times. Associations between class membership and socio-demographics, use patterns, motives, supply sources, adverse outcomes, and use of other substances were measured using ANOVA and chi-squared tests. Multinomial regression identified the factors associated with latent class membership.

RESULTS

Three latent classes (moderately heavy: 21.8%, heavy: 68.2%, very heavy: 10%) had average weekly cannabis intakes of 2.4, 5.5, and 18.3 g, respectively. Very heavy users were older ([Formula: see text]=17.77, p < 0.01), less educated [Formula: see text]=36.80, p < 0.001), and had used cannabis for longer (F = 4.62, p = 0.01). CAST scores (F = 26.51, p < 0.001) increased across the classes. The prevalence of past-month alcohol use was lower among the heaviest users ([Formula: see text]=5.95, p = 0.05). Cannabis was usually obtained from a club by very heavy users ([Formula: see text]=20.95, p < 0.001).

CONCLUSIONS

People who use cannabis heavily present three groups according to frequency and quantity of cannabis consumption. Use intensity is associated with increased cannabis-related problems. Differences among heavy users must be considered in harm reduction interventions in cannabis clubs and indicated prevention.

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.

College students' knowledge about opioids and implications for the opioid crisis

OBJECTIVE

This study assessed undergraduate unhealthy substance use, levels of knowledge about opioid pharmacology, unhealthy use and safety, and students' perceptions about their level of knowledge.

PARTICIPANTS

Participants were undergraduate students at a large, private university in the Northeast.

METHODS

This study employed a cross-sectional study design using an online survey. A convenience sample of undergraduate students (N = 317) described their actual and perceived levels of opioid knowledge and their self-reported substance use.

RESULTS

Objective answers to quiz-style questions about opioids showed knowledge deficits. Participants rated themselves as slightly less knowledgeable than the "average student." Ten percent of students surveyed had used opioids unhealthily at some point in their lifetime. Those reporting unhealthy opioid use had higher subjective and objective opioid knowledge scores.

CONCLUSIONS

University students' subjective and objective knowledge of opioids warrants more effective and engaging substance use education on college campuses.

Correlates of high phosphatidylethanol (PEth) levels and their concordance with self-reported heavy alcohol consumption among men who have sex with men who binge drink alcohol

BACKGROUND

Heavy alcohol use, including binge drinking, is associated with high morbidity and mortality among men who have sex with men (MSM). Self-reported alcohol measures may lead to inaccurate estimates due to recall and social desirability biases. Objective alcohol biomarkers like phosphatidylethanol (PEth) can be used to corroborate self-report and could help to inform treatment approaches and research strategies for alcohol using MSM.

METHODS

From 2015 to 2020, alcohol using MSM ≥18 years were enrolled in a randomized controlled trial evaluating the efficacy of naltrexone in reducing binge drinking. Using this trial's baseline data, we applied multivariable logistic regression to identify the correlates of high PEth levels (i.e., ≥87 ng/ml) and concordance between PEth levels and self-reported heavy drinking.

RESULTS

Of 118 MSM, 64% had PEth levels ≥87 ng/ml and 72% had PEth levels that were concordant with self-reported heavy alcohol use. Factors significantly associated in separate models with elevated PEth levels were income ≥$60,000 (adjusted odds ratio [aOR] = 4.09; 95% CI = 1.13 to 14.82), being employed (aOR = 4.04; 95% CI = 1.45 to 11.32), episodic cannabis use (aOR = 4.63; 95% CI = 1.27 to 16.92), and any alcohol/substance use prior to or during anal intercourse (aOR = 2.52; 95% CI = 1.08 to 5.90). Living with HIV was associated with significantly lower odds of elevated PEth levels (aOR = 0.23; 95% CI = 0.09 to 0.61). Factors associated with significantly higher concordance between PEth levels and self-reported heavy alcohol use included at least weekly use of poppers (aOR = 6.41; 95% CI = 1.27 to 32.28) and polysubstance use (aOR = 2.53; 95% CI = 1.02 to 6.27). Living with HIV was associated with lower odds of concordance (aOR = 0.36; 95% CI = 0.14 to 0.97).

CONCLUSIONS

PEth may enhance the detection of heavy drinking among MSM, including the identification of subpopulations that may benefit from targeted alcohol reduction interventions. However, PEth values for MSM living with HIV showed modest concordance with self-reported alcohol use and may need to be supplemented with additional biomarkers or evaluated against a different cutoff.

Use of Population-Based Surveys for Estimating the Population Size of Persons Who Inject Drugs in the United States

BACKGROUND

In the United States, injection is an increasingly common route of administration for opioids and other substances. Estimates of the number of persons who inject drugs (PWID) are needed for monitoring risk-specific infectious disease rates and health services coverage.

METHODS

We reviewed design and instruments for 4 national household surveys, 2012-2016, for their ability to produce unbiased injection drug use (IDU) prevalence estimates. We explored potential analytic adjustments for reducing biases through use of external data on (1) arrest, (2) narcotic overdose mortality, and (3) biomarker-based sensitivity of self-reported illicit drug use.

RESULTS

Estimated national past 12 months IDU prevalence ranged from 0.24% to 0.59% across surveys. All surveys excluded unstably housed and incarcerated persons, and estimates were based on <60 respondents reporting IDU behavior in 3 surveys. No surveys asked participants about nonmedical injection of prescription drugs. Analytic adjustments did not appreciably change IDU prevalence estimates due to suboptimal specificity of data points.

CONCLUSIONS

PWID population size estimates in the United States are based on small numbers and are likely biased by undercoverage of key populations and self-report. Novel methods as discussed in this article may improve our understanding of PWID population size and their health needs.

Bridging the Digital Divide Among Racial and Ethnic Minority Men Who Have Sex With Men to Reduce Substance Use and HIV Risk: Mixed Methods Feasibility Study

BACKGROUND

Ecological momentary assessment (EMA) is a promising data collection tool for mobile health interventions targeting episodic health behaviors. For substance-using men who have sex with men (SUMSM), EMA is becoming more widely utilized in efforts to characterize substance use and sexual risk factors for HIV transmission. However, recent literature demonstrates emerging concerns over compliance and lower EMA engagement and data concordance among racial and ethnic minority SUMSM.

OBJECTIVE

This study aimed to provide a qualitative evaluation of the barriers and facilitators of EMA as a data collection tool among racial and ethnic minority SUMSM.

METHODS

Between October and November 2017, 45 racial and ethnic minority SUMSM were recruited from a list of prior research participants at the San Francisco Department of Public Health to participate in daily EMA surveys on their substance use and sexual health behaviors for 1 week, followed by in-person focus groups (FGs). A total of 4 FGs explored the participants' experiences with the surveys, issues regarding privacy and confidentiality, and suggestions for improvement. Qualitative analysis was performed using content analysis. Descriptive statistics and Fisher exact tests were used to assess the associations between demographics or substance use behaviors and EMA completion.

RESULTS

Overall, 93.9% (295/314) of all delivered surveys were initiated, and of those, 98.0% (289/295) were completed. Neither participant demographics, including race (P=.65) or age (P=.43), nor substance use behaviors, including the frequency of alcohol (P=.40) or methamphetamine (P=.91) use or any cocaine (P=.28), crack (P=.99), or polysubstance use (P=.24), were found to be associated with survey completion. Overall, participants were receptive to the text message-based EMA surveys. Facilitators included survey timing, user-friendly survey design, survey-stimulated self-reflection, coding of sensitive phrases, and other privacy benefits of a mobile survey. Barriers included an inability to correct texting errors and participants' perception of judgment or stigmatization related to questions about condomless sex. To improve EMA compliance and uptake, participants suggested adding response confirmations, clarifying survey language, and continuing to diversify the study audience.

CONCLUSIONS

EMA appears to be feasible and acceptable among this sample of racial and ethnic minority SUMSM. Close attention to EMA study design and the development of nonjudgmental, contextualized questions regarding stigmatized health behaviors may be critical to further improve EMA compliance.

Comparison of timeline follow-back self-report and oral fluid testing to detect substance use in adult primary care patients

BACKGROUND

Timeline Follow-back (TLFB) interviews using self-report are often used to assess substance use. Oral fluid testing (OFT) offers an objective measure of substance use. There are limited data on the agreement between TLFB and OFT.

METHODS

In this secondary analysis from a multisite study in five primary care sites, self-reported TLFB and OFT data collected under confidential conditions were compared to assess concordance (N=1799). OFT samples were analyzed for marijuana, heroin, cocaine, and non-medical use of prescription opioids. Demographic differences in discordance relative to TLFB and OFT concordant results for marijuana, the only substance with an adequate sample size in this analysis, were examined using multinomial logistic regression.

RESULTS

Overall concordance rates between TLFB and OFT were 94.9 % or higher for each substance, driven by large subgroups with no use. Among participants with discordant use, marijuana was the only substance with lower detection on OFT than self-report (27.6 % OFT-positive only vs 32.2 % TLFB-positive only), whereas cocaine (65.6 % vs 8.6 %), prescription opioids (90.4 % vs 6.0 %), and heroin (40.7 % vs 26.0 %) all had higher detection via OFT than TLFB. Participants who reported marijuana use but had a negative OFT were more likely to be younger, Hispanic, and White compared to those with TLFB and OFT concordant positive results.

CONCLUSIONS

TLFB and OFT show disparate detection of different substances. Researchers should consider the implications of using either self-report or oral fluid testing in isolation, depending on the substance and collection setting. Triangulating multiple sources of information may improve detection of drug use.

Assessing an Epidemic: Utility of the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition Level 2 Substance Use Screener in Adult Psychiatric Inpatients

BACKGROUND

Inpatient psychiatric hospitals provide an important point of care for assessing and stabilizing substance use and for facilitating linkage to appropriate treatment. Toxicology screening provides a key measure of substance use yet may miss many cases of substance use because of variable windows of detection and the limited scope of substances assessed. This study assesses the utility of the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) Level 2 Substance Use screener as a supplemental tool for identifying substance use by self-report within an inpatient psychiatric hospital setting.

METHODS

From a larger sample of 97 adult psychiatric inpatients, 60 who underwent drug toxicology testing and completed the DSM-5 screener were assessed. We examined the sensitivity and specificity of the self-report screener in comparison with drug toxicology test results collected by chart review.

RESULTS

Sensitivity of the DSM-5 screener varied across substances assessed: The self-report measure identified 100% of individuals who tested positive for opioid use, 83% who tested positive for cannabis use, 50% who tested positive for cocaine use, and 37% who tested positive for benzodiazepine use. The self-report measure also identified 27 instances among 60 participants in which substance use identified by self-report was not detected by toxicology testing.

CONCLUSION

The brief and easily administered DSM-5 Level 2 Substance Use screener shows promise for improving identification of substance use in an inpatient psychiatric hospital setting. This measure may also provide psychiatric inpatient nursing staff with a means of working collaboratively with patients to assess substance use and coordinate appropriate treatment plans.

Community Screening, Identification, and Referral to Primary Care, for Hepatitis C, B, and HIV Among Homeless Persons in Los Angeles

People experiencing homelessness are disproportionally affected by drug and alcohol use and by their serious health consequences. In this study, 137 adults from the "UCLA/ARG/RAND Homeless Hepatitis Study" who were sampled from shelters and meal programs in the Skid Row of Los Angeles and screened for HIV or HCV or HBV infection. Those who tested positive for these infections were counseled about their infections and referred to primary care. They were followed-up at 1 month with interviews to identify rates, and predictors, of seeking primary care. Participants were 87.5% male, mean age of 48.6 years (SD: 8.2); most were Black (77.4%) and were chronically homeless (> 12 months). A majority (70%) had a regular source of care; 78% were lifetime marijuana users, 56% were lifetime cocaine users and 51% had injected intravenously during the past year. Among this sample, 118 participants (86.1%) tested seropositive for HCV infection, 79 (57.7%) HBV infection and 18 (13.1%) HIV infection. At 1-month follow-up, 102 participants (74.5%) attended the clinic they were referred to. The only variable associated with attending the clinic was having slept in a shelter during the previous night versus other sleeping conditions [Odds ratio (95% CI): 3 .0 (1.07-8.42), p = 0.03]. This model offers a simple and efficacious approach to seeking, testing, counseling, and referral to treatment of community-based adults experiencing homelessness with HIV, HCV and/or HBV infection and linking them to primary care. Being sheltered may be the key facilitator for homeless seeking primary care.

What happens to agreement over time? A longitudinal study of self-reported substance use compared to saliva toxicological testing among subsidized housing residents

The agreement between self-reported and toxicologically verified substance use provides important information about the validity of self-reported use. While some studies report aggregate agreement across follow-up points, only a few have examined the agreement at each time point separately. An overall rate of agreement across time may miss changes that occur as people progress through a research study. In this study, a sample of 644 adults (43.8% male, 32.6% White, 57.0% Black, 90.2% ages 36+) residing in subsidized housing was used to determine the agreement between self-reported use and saliva toxicological testing for marijuana, cocaine, PCP, amphetamine, and methamphetamine at three different time points. Agreement between saliva toxicological testing and self-report ranged between 84.2% and 94.3% for different substances over time. Higher rates of agreement were found for cocaine than had been reported by previous studies. Statistically significant differences in the odds ratios of concordance over time (baseline, 6-month, and 12-month follow-up) were found for marijuana and the combined category for PCP, amphetamine, and methamphetamine. Our findings suggest that oral fluid drug tests generally withstand community field assessments and result in relatively high levels of agreement for marijuana, cocaine, PCP, amphetamine, and methamphetamine use, when compared to self-report. Because of the ease of sample collection and low chance of adulteration, we conclude that saliva testing is a viable method for toxicological confirmation of substance use behavior in this setting.

What's the influence of social interactions on substance use and treatment initiation? A prospective analysis among substance-using probationers

INTRODUCTION

A person's social environment greatly affects the likelihood of substance use, which in turn affects risk for criminal behavior. This study examined how people's social environment early in probation contributed to later substance use and treatment outcome, both of which predict probation success.

METHODS

Data were analyzed from a randomized controlled trial of substance-using probationers (N = 316). Moderation analyses assessed the relationship between social support near the start of probation and substance use and treatment initiation after 2 and 6 months.

RESULTS

Abstinence at 2-months was associated with better baseline measures of support quality (more positive support, fewer negative interactions, and reduced conflict). Similar associations were identified for 6-month abstinence including better baseline quality, more positive support, and less family and peer conflict. There were no significant associations between the baseline social support and treatment initiation at 2-months. However, poorer baseline quality support and more negative interactions predicted increased treatment initiation at 6-months.

CONCLUSIONS

Social support and the quality of an offender's social network have important implications for substance use and treatment compliance. The criminal justice system emphasizes ways to minimize negative social influences among offenders (i.e., probation conditions that limit contact with other offenders). However, this study suggests that behavior change is a function of not only reducing negative influences but also increasing positive or good quality supports.

Drug Use by Music Festival Attendees: A Novel Triangulation Approach Using Self-Reported Data and Test Results of Oral Fluid and Pooled Urine Samples

Background: Self-reported data are commonly used when investigating illicit substance use. However, self-reports have well-known limitations such as limited recall and socially desirable responding. Mislabeling or adulteration of drugs on the illicit market may also cause incorrect reporting. Objectives: We aimed to examine what could be gained in terms of illicit drug use findings among music festival attendees when including biological sample test results in the assessment. Methods: We included 651 attendees at three music festivals in Norway from June to August 2016. Self-reported drug use was recorded using questionnaires, and samples of oral fluid were analyzed to detect use of illicit drugs. In addition, we analyzed samples of pooled urine from portable toilets at each festival. Results: All methods identified cannabis, MDMA, and cocaine as the most commonly used drugs. Overall, 6.6% of respondents reported use of illicit substances during the previous 48 hours. Oral fluid testing identified a larger number of drug users as 12.6% tested positive for illicit drugs. In oral fluid testing, we identified ketamine and three new psychoactive substances (NPS) that had not been reported on the questionnaire. In pooled urine testing, we identified amphetamine and three additional NPS that were neither reported used nor found in oral fluid samples. Conclusions/Importance: Drug testing of biological samples proved to be an important supplement to self-reports as a larger number of illicit substances could be detected.

Correspondence between Oral Fluid Drug Test Results and Self-Reported Illicit Drug Use among Music Festival Attendees

BACKGROUND

Use of illicit substances is often under-reported. Testing positive in oral fluid provides an objective confirmation of recent intake.

OBJECTIVES

To examine the agreement between oral fluid test results and self-reported substance use among music festival attendees, and factors associated with reporting past 48 h drug use among users identified by drug testing.

METHODS

One thousand three hundred nine participants were recruited from six music festivals in Norway (June-August 2016). They completed a questionnaire and provided oral fluid samples analyzed for amphetamines, MDMA, tetrahydrocannabinol (cannabis), and cocaine. Additionally, their blood alcohol levels were measured.

RESULTS

Overall, 5.5% reported use of amphetamines, cannabis, cocaine, and/or MDMA during past 48 h in the questionnaire, whereas 10.8% tested positive in oral fluid. Only 16.7% of identified cocaine users and 31.1% of identified MDMA users reported past 48 h cocaine or MDMA use, respectively. Higher proportions of identified cannabis and amphetamine users reported past 48 h use (53.8% and 55.6%, respectively). Multivariable logistic regression analysis showed that among participants who tested positive, those reporting weekly illicit substance use (Adjusted Odds Ratio [AOR] 30.6; 95% Confidence Interval [CI] 6.3-147.9), and using such substances when younger than 18 years (AOR 5.0; 95% CI 1.9-13.4) were more likely to report past 48 h use. Conclusions/Importance: Oral fluid testing appears to be an important tool when studying illicit substance use among music festival attendees, as significant under-reporting was observed. Among those testing positive, regular, and experienced users were more likely to report recent use, compared to less regular and experienced users.

Correlates of Validity of Self-Reported Methamphetamine Use among a Sample of Dependent Adults

BACKGROUND

Self-reported data are widely used in substance-use research, yet few studies have assessed the validity of self-reported methamphetamine use compared to biological assays.

OBJECTIVES

We sought to assess the validity and correlates of validity of self-reported methamphetamine use compared to urine toxicology (UTOX).

METHODS

Using a sample of methamphetamine-dependent individuals enrolled in a randomized controlled pharmacotherapy trial in the United States (n = 327 visits among 90 participants), we calculated sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and the kappa coefficient of self-reported methamphetamine use in the past 3 days compared to UTOX, as well as the NPV of self-reported methamphetamine use over an extended recall period of 1 month. We used multivariable logistic regression models to assess correlates of concordance between self-reported methamphetamine use and UTOX.

RESULTS

The sensitivity of self-reported methamphetamine use in the past 3 days was 86.7% (95% confidence intervals (95%CI): 81.4%-91.4%), the specificity was 85.3% (77.7-91.3), the PPV was 91.5% (86.9-94.8), and the NPV was 78.0% (69.4-86.1), compared to UTOX (kappa = 0.71). The NPV over the extended recall period was 70.6% (48.0-85.7). In multivariable analyses, validity of self-reported methamphetamine use was higher for older participants but lower during follow-up compared to baseline and when polysubstance use or depressive symptoms were reported. Conclusions/Importance: Our sample of methamphetamine-dependent adults reported recent methamphetamine use with high validity compared to UTOX. Validity increased with age but decreased when participants reported depressive symptoms or polysubstance use as well as later in the study timeline and during longer recall periods.