Using wastewater-based epidemiology to estimate drug consumption—Statistical analyses and data presentation

Aim Analysis of wastewater samples can be used to assess population drug use, but reporting and statistical issues have limited the utility of the approach for epidemiology due to analytical results that are below the limit of quantification or detection. Unobserved or non-quantifiable—censored—data are common and likely to persist as the methodology is applied to more municipalities and a broader array of substances. We demonstrate the use of censored data techniques and account for measurement errors to explore distributions and annual estimates of the daily mean level of drugs excreted per capita. Measurements Daily 24-hour composite wastewater samples for 56 days in 2009 were obtained using a random sample stratified by day of week and season for 19 municipalities in the Northwest region of the U.S. Methods Methamphetamine, benzoylecgonine (cocaine metabolite), 3,4-ethylenedioxymethamphetamine (MDMA), methadone, oxycodone and hydrocodone were identified and quantified in wastewater samples. Four statistical approaches (reporting censoring, maximum likelihood estimation, Kaplan-Meier estimates, or complete data calculations) were used to estimate an annual average, including confidence bounds where appropriate, dependent upon the amount of censoring in the data. Findings The proportion of days within a year with censored data varied greatly by drug across the 19 municipalities, with MDMA varying the most (4% to 94% of observations censored). The different statistical approaches each needed to be used given the levels of censoring of measured drug concentrations. Figures incorporating confidence bounds allow visualization of the data that facilitates appropriate comparisons across municipalities. Conclusions Results from wastewater sampling that are below detection or quantification limits contain important information and can be incorporated to create a more complete and valid estimate of drug excretion

Interpreting Methamphetamine Levels in a High-Use Community

Illicit drug use is a largely hidden phenomenon and population measures are notoriously problematic. Reliable and valid data for local, regional and national public health and other interventions are needed. To address this information we examined temporal trends within and across weeks in methamphetamine (MA) in a single location in order to inform a sampling plan for understanding long-term trends in MA use based on sampling raw influent to waste water treatment plants. The measured concentrations in wastewater are used to estimate the total mass of MA consumed MA rather than the number of doses due to the uncertainty surrounding methamphetamine purity, mass of MA per dose, and the number of doses used per day. Results from a region with high levels of MA use indicate that MA levels do not differ significantly between weekdays and weekends (p=0.1), consistent with a predominately regular, daily use pattern use. The potential contribution of legal sales of d- and l-MA to the mass of MA consumed within the community was estimated to range from 3-8%. Limitations and uncertainties associated with estimating the mass of MA consumption include small contributions of prescription and over-the-counter drugs that are metabolized to MA as well as measurement and sampling variability.Keywords: Temporal patterns, Epidemiology wastewater, Methamphetamine (MA)Keywords: Temporal patterns, Epidemiology wastewater, Methamphetamine (MA

Profiles of illicit drug use during annual key holiday and control periods in Australia: wastewater analysis in an urban, a semi-rural and a vacation area

Aims To examine changes in illicit drug consumption between peak holiday season (23 December3 January) in Australia and a control period two months later in a coastal urban area, an inland semi-rural area and an island populated predominantly by vacationers during holidays. Design Analysis of representative daily composite wastewater samples collected from the inlet of the major wastewater treatment plant in each area. Setting Three wastewater treatment plants. Participants Wastewater treatment plants serviced approximately 350000 persons in the urban area, 120000 in the semi-rural area and 11002400 on the island. Measurements Drug residues were analysed using liquid chromatography coupled to a tandem mass spectrometer. Per capita drug consumption was estimated. Changes in drug use were quantified using Hedges' g. Findings During the holidays, cannabis consumption in the semi-rural area declined (g=2.8) as did methamphetamine (0.8), whereas cocaine (+1.5) and ecstasy (+1.6) use increased. In the urban area, consumption of all drugs increased during holidays (cannabis +1.6, cocaine +1.2, ecstasy +0.8 and methamphetamine +0.3). In the vacation area, methamphetamine (+0.7), ecstasy (+0.7) and cocaine (+1.1) use increased, but cannabis (0.5) use decreased during holiday periods. Conclusions While the peak holiday season in Australia is perceived as a period of increased drug use, this is not uniform across all drugs and areas. Substantial declines in drug use in the semi-rural area contrasted with substantial increases in urban and vacation areas. Per capita drug consumption in the vacation area was equivalent to that in the urban area, implying that these locations merit particular attention for drug use monitoring and harm minimisation measures

Sewage-based epidemiology requires a truly transdisciplinary approach

If asked whether you had consumed illicit drugs recently, would you admit it? If yes, could you precisely recall types of drug, times and amounts used? If you were the person commissioned with the task of quantifying drug use, what approach would you use given the social stigma attached with such behavior? We measure drug residues in sewage, which represents urine of entire populations, to provide an objective estimate of total drug use in a region. In transdisciplinary projects, sewage-based results provide valuable information at unrivaled spatiotemporal resolution complementing traditional data

Effects of sewer conditions on the degradation of selected illicit drug residues in wastewater

The stability of five illicit drug markers in wastewater was tested under different sewer conditions using laboratory-scale sewer reactors. Wastewater was spiked with deuterium labelled isotopes of cocaine, benzoyl ecgonine, methamphetamine, MDMA and 6-acetyl morphine to avoid interference from the native isotopes already present in the wastewater matrix. The sewer reactors were operated at 20°C and pH 7.5, and wastewater was sampled at 0, 0.25, 0.5, 1, 2, 3, 6, 9 and 12h to measure the transformation/degradation of these marker compounds. The results showed that while methamphetamine, MDMA and benzoyl ecgonine were stable in the sewer reactors, cocaine and 6-acetyl morphine degraded quickly. Their degradation rates are significantly higher than the values reportedly measured in wastewater alone (without biofilms). All the degradation processes followed first order kinetics. Benzoyl ecgonine and morphine were also formed from the degradation of cocaine and 6-acetyl morphine, respectively, with stable formation rates throughout the test. These findings suggest that, in sewage epidemiology, it is essential to have relevant information of the sewer system (i.e. type of sewer, hydraulic retention time) in order to accurately back-estimate the consumption of illicit drugs. More research is required to look into detailed sewer conditions (e.g. temperature, pH and ratio of biofilm area to wastewater volume among others) to identify their effects on the fate of illicit drug markers in sewer systems

An analysis of ethical issues in using wastewater analysis to monitor illicit drug use

New Zealand is considered to have unusual drug use patterns by international standards. However, this understanding has largely been obtained from social surveys where respondents self-report use. The aim of this paper is to conduct the first wastewater study of drug use in Auckland

Improving Public Health Through Access to and Utilization of Medication Assisted Treatment

Providing access to and utilization of medication assisted treatment (MAT) for the treatment of opioid abuse and dependence provides an important opportunity to improve public health. Access to health services comprising MAT in the community is fundamental to achieve broad service coverage. The type and placement of the health services comprising MAT and integration with primary medical care including human immunodeficiency virus (HIV) prevention, care and treatment services are optimal for addressing both substance abuse and co-occurring infectious diseases. As an HIV prevention intervention, integrated (same medical record for HIV services and MAT services) MAT with HIV prevention, care and treatment programs provides the best “one stop shopping” approach for health service utilization. Alternatively, MAT, medical and HIV services can be separately managed but co-located to allow convenient utilization of primary care, MAT and HIV services. A third approach is coordinated care and treatment, where primary care, MAT and HIV services are provided at distinct locations and case managers, peer facilitators, or others promote direct service utilization at the various locations. Developing a continuum of care for patients with opioid dependence throughout the stages MAT enhances the public health and Recovery from opioid dependence. As a stigmatized and medical disenfranchised population with multiple medical, psychological and social needs, people who inject drugs and are opioid dependent have difficulty accessing services and navigating medical systems of coordinated care. MAT programs that offer comprehensive services and medical care options can best contribute to improving the health of these individuals thereby enhancing the health of the community

Prescribed opioids in primary care: cross sectional and longitudinal analyses of influence of patient and practice characteristics

Objectives: To examine trends in opioid prescribing in primary care, identify patient and general practice characteristics associated with long-term and stronger opioid prescribing, and identify associations with changes in opioid prescribing. Design: Trend, cross-sectional and longitudinal analyses of routinely recorded patient data. Setting: 111 primary care practices in Leeds and Bradford, United Kingdom. Participants: We observed 471828 patient-years in which all patients represented had at least one opioid prescription between April 2005 and March 2012. A cross-sectional analysis included 99847 patients prescribed opioids between April 2011 and March 2012. A longitudinal analysis included 49065 patient-years between April 2008 and March 2012. We excluded patients with cancer or treated for substance misuse. Main outcome measures: Long-term opioid prescribing (four or more prescriptions within 12 months), stronger opioid prescribing, and stepping up to or down from stronger opioids. Results: Opioid prescribing in the adult population almost doubled for weaker opioids over 2005-12 and rose over six-fold for stronger opioids. There was marked variation amongst general practices in the odds of patients stepping up to stronger opioids compared to those not stepping up (range 0.31 to 3.36), unexplained by practice-level variables. Stepping up to stronger opioids was most strongly associated with being underweight (adjusted odds ratio 3.26, 1.49-7.17), increasing polypharmacy (4.15, 3.26-5.29 for 10 or more repeat prescriptions), increasing numbers of primary care appointments (3.04, 2.48-3.73 for over 12 appointments in the year), and referrals to specialist pain services (5.17, 4.37-6.12). Compared with women under 50 years, men under 50 were less likely to step down once prescribed stronger opioids (0.53, 0.37-0.75). Conclusions: Whilst clinicians should be alert to patients at risk of escalated opioid prescribing, much prescribing variation may be attributable to clinical behaviour. Effective strategies targeting both clinicians and patients are needed to curb rising prescribing, especially of stronger opioids

Valuing health states: is the MACBETH approach useful for valuing EQ-5D-3L health states?

Background Quality Adjusted Life Years (QALYs) are a key outcome measure widely used within health technology assessment and health service research studies. QALYs combine quantity and quality of life, with quality of life calculations relying on the value of distinct health states. Such health states’ values capture the preferences of a population and have been typically built through numerical elicitation methods. Evidence points to these value scores being influenced by methods in use and individuals reporting cognitive difficulties in eliciting their preferences. Evidence from other areas has further suggested that individuals may prefer using distinct elicitation techniques and that this preference can be influenced by their numeracy. In this study we explore the use of the MACBETH (Measuring Attractiveness by a Categorical Based Evaluation Technique) non-numerical preference elicitation approach for health states’ evaluation. Methods A new protocol for preference elicitation based on MACBETH (only requiring qualitative judgments) was developed and tested within a web survey format. A sample of the Portuguese general population (n=243) valued 25 EQ-5D-3L health states with the MACBETH protocol and with a variant of the time trade-off (TTO) protocol, for comparison purposes and for understanding respondents’ preference for distinct protocols and differences in inconsistent evaluations. Respondents answered to a short numeracy test, and basic socio-economic information collected. Results Results show that the mean values derived from MACBETH and the TTO variant are strongly correlated; however, there are substantial differences for several health states’ values. Large and similar numbers of logical inconsistencies were found in respondents’ answers with both methods. Participants with higher levels of numeracy according to the test preferred expressing value judgments with MACBETH, while participants with lower levels were mostly indifferent to both methods. Higher correlations between MACBETH and TTO variant evaluations were observed for individuals with higher numeracy. Conclusion Results suggest that it is worth researching the use of non-numerical preference elicitation methods. Numeracy tests more appropriate for preference elicitation when no explicit considerations of uncertainty are made need to be explored and used. Further behavioural research is needed to fully understand the potential for using these methods in distinct settings (e.g. in different evaluation contexts and in face-to-face and non-face-to-face environments), as well as to explore the effect of literacy on assessments and on respondents’ preferences.UID/MULTI/4066/2016info:eu-repo/semantics/publishedVersio