Search

Abstract: Aims: To estimate and test the difference in rates of violent and non‐violent crime during medicated and non‐medicated methadone treatment episodes. Design, Setting and Participants: The study involved linkage of population level administrative data (health and justice) for all individuals (n = 14 530) in British Columbia, Canada with a history of conviction and who filled a methadone prescription between 1 January 1998 and 31 March 2015. Methadone maintenance treatment was the primary independent variable and was treated as a time‐varying exposure. Each participant's follow‐up (mean: 8 years) was divided into medicated (methadone was dispensed) and non‐medicated (methadone was not dispensed) periods with mean durations of 3.3 and 4.6 years, respectively. Measurements: Socio‐demographics of participants were examined along with the main outcomes of violent and non‐violent offences. Findings: During the first 2 years of treatment (≤ 2.0 years), periods in which methadone was dispensed were associated with a 33% lower rate of violent crime [0.67 adjusted hazard ratio (AHR), 95% confidence intervals (CI) = 0.59, 0.76] and a 35% lower rate of non‐violent crime (0.65 AHR, 95% CI = 0.62, 0.69) compared with non‐medicated periods. This equates to a risk difference of 3.6 (95% CI = 2.6, 4.4) and 37.2 (95% CI = 33.0, 40.4) fewer violent and non‐violent offences per 100 person‐years, respectively. Significant but smaller protective effects of dispensed methadone were observed across longer treatment intervals (2.0 to ≤ 5.0 years, 5.0 to ≤ 10.0 years). Conclusions: Among a cohort of Canadian offenders, rates of violent and non‐violent offending were lower during periods when individuals were dispensed methadone compared with periods in which they were not dispensed methadone. [ABSTRACT FROM AUTHOR]

Background: Methadone maintenance therapy (MMT) is among the most effective treatment modalities available for the management of opioid use disorder. However, the effect of MMT on mortality, and optimal strategies for delivering methadone are less clear. This study sought to estimate the effect of low-threshold MMT and its association with all-cause mortality among persons who inject drugs (PWID) in a setting where methadone is widely available through primary care physicians and community pharmacies at no cost through the setting's universal medical insurance plan.Methods: Between May, 1996 and December, 2011 data were collected as part of two prospective cohort studies of PWID in Vancouver, Canada, and were linked to the provincial vital statistics database to ascertain rates and causes of death. The association of MMT with all-cause mortality was estimated using multivariable extended Cox regression with time-dependent variables.Results: Of 2335 PWID providing 15027 person-years of observation, 511 deaths were observed for a mortality rate of 3.4 (95% Confidence Interval [CI]: 3.1-3.7) deaths per 100 person-years. After adjusting for potential confounders including age and HIV seropositivity, MMT enrolment was found to be associated with lower mortality (adjusted hazard ratio [AHR]=0.73, 95% CI: 0.61-0.88).Conclusions: While observed all-cause mortality rates among PWID in this setting were high, participation in low-threshold MMT was significantly associated with improved survival. These findings add to the known benefits of providing low-threshold MMT on reducing the harms associated with injection drug use. [ABSTRACT FROM AUTHOR]

There is concern that industrial emissions of manganese (Mn) and the use of Mn-containing compounds as fuel additives might increase the population risk of Parkinson''s disease (PD)-like disorders. We investigated associations between the diagnosis and treatment of PD and markers of exposure to vehicle exhaust and industrial emissions of Mn within a cohort of 110,000 subjects in the cities of Toronto and Hamilton, Canada. Methylcyclopentadienyl manganese tricarbonyl (MMT) has been added to Canadian gasoline since 1976 and steelmaking in Hamilton emits Mn to the air. Using residential postal codes, subjects were mapped to: (1) residence locations close to traffic and to neighbourhood levels of NO2, as markers of traffic-generated air pollution (TGAP); and, (2) neighbourhood levels of ambient Mn in Hamilton, as measured by the Mn fraction of total suspended particulate. Subjects were linked to Ministry of Health administrative databases, 1992–1999, to identify physicians’ diagnoses of PD and prescriptions for l-Dopa containing medications. In Toronto, we found no association between PD and the markers of TGAP. In Hamilton, the odds ratio for a physician''s diagnosis of PD was 1.034 (1.00–1.07) per 10ng/m3 increase in Mn in TSP. The estimate of the “doubling exposure” for physician-diagnosed PD was about 150ng/m3 Mn in TSP. Examination of prevalence curves suggested that exposure to ambient Mn advances the age of diagnosis of PD, consistent with the theory that exposure to Mn adds to the natural loss of neurons attributable to the aging process. [Copyright &y& Elsevier]

Methylcyclopentadienyl manganese tricarbonyl (MMT), is an organic derivative of Mn used as an anti-knock agent in Canadian unleaded gasoline since 1976. This study aims to estimate Mn emissions from MMT source in the Canadian environment as well as the Mn pollution index per capita in each of the Canadian provinces. In concomitance, lead emissions will also be addressed. The quantities of Mn and Pb used in gasoline were calculated from data on annual gasoline sales in Canada supplied by Statistics Canada. Obviously, the Pb emission profile shows a substantial decrease with an annual average of −28% until 1991, when MMT totally replaced Pb in Canadian gasoline. The case of Mn is quite different. Since emission rates of Mn at the tailpipe vary between 6 and 45%, the quantities released into the atmosphere were calculated for each of these rates, as well as for 100 and 25% emission rate scenarios. For 1981 and 1999, the quantities of Mn used in gasoline were estimated at 101 122 and 344 880 kg, respectively. Based on the realistic 25% emission rate scenario and a concentration of 0.009 g/l of Mn in gasoline, Mn emissions from car exhausts were estimated to 25 280 and 86 220 kg, respectively. The mean annual increase in emission rate between 1981 and 1999 is 7.34%. The atmospheric Mn pollution index seems to be stable over time, and it varies from 0.0024 kg/capita to 0.0041 kg/capita in 1999. In the context of a notable decrease in Mn emissions from industrial sources, these results suggest that the combustion of MMT used in gasoline may be an important factor contributing to maintaining stable atmospheric Mn concentrations instead of a significant decrease due to reduced industrial emissions. [Copyright &y& Elsevier]

Methylcyclopentadienyl manganese tricarbonyl (MMT) is an organic derivative of manganese (Mn) used in Canada as an antiknock agent and octane enhancer in gasoline. In a recent study, we measured the atmospheric concentrations of MMT at selected outdoor sites in Montreal. Results ranged from 0.18 to 25 ng m-3 (expressed as Mn) and do not reflect personal exposure levels. The highest values were obtained at a gas station (mean of 12 ng m-3). By extension, evaluation of the personal exposure of gas station attendants constitutes a promising area of research. In an earlier study, the sampling method used allowed the possibility that the samples could have included ultra-fine particles, which may have passed through the filters used, and the chemical analysis used (neutron activation) did not discriminate between MMT and other Mn compounds. The present study aims to validate an improved sampling method and to assess personal exposure of gas station attendants to MMT. The MMT recovery of the new sampling method was found to be 91.6%. The exposure of 13 gas station attendants was measured on 1 to 6 occasions each (n = 32). They were working in two busy gas stations located in Montreal and they were asked to wear a portable pump for 2 hr. The air was pumped through two tubes in series filled with the adsorbent Tenax TA™, with glass wool plugs at both ends. The tubes were wrapped in aluminum foil and samples were analyzed for MMT by gas chromatograph-atomic emission detector (GC-AED). Results vary between 0.3 and 11.4 ng m-3, with a mean of 3.9 ng m-3. The highest values obtained in the first study may be due to the analytical techniques used previously, where detection of different Mn compounds other than MMT was possible. Since GC-AED is specific to MMT in the samples, the MMT found in air raises doubt as to the time required for the photodegradation of MMT. [ABSTRACT FROM AUTHOR]

Background: Ever-increasing numbers of opioid use disorder (OUD) in Canada has created the recent opioid crisis. One common treatment for OUD is methadone maintenance treatment (MMT). Various factors, including being a parent which entails specific stressors, may increase susceptibility to negative treatment outcomes. This study aims to investigate differences between OUD patients with and without children in socio-demographic and clinical outcomes. Methods: Data for this study are part of a larger program. All participants are 18+ years old with OUD, provided consent, and receiving MMT. We performed a multivariable logistic regression to examine the differences between participants' parental status, sociodemographic variables, and clinical parameters including MMT outcomes. We performed subgroup analyses on individuals with children younger than 18. Results: A total of 1099 participants were included, with 64% having children. Participants with children were older (OR 1.06, 95% CI 1.04, 1.08), more likely to be female (OR 2.39, 95% CI 1.75, 3.27), living with a partner (OR 1.75, 95% CI 1.27, 2.41), first exposed to opioids through a prescription (OR 1.517, 95% CI 1.13, 2.04) and had lower levels of education (OR 1.86, 95% CI 1.20, 2.87). There was no significant difference in illicit opioid use patterns between groups. Same results held true in the subgroup analyses based on the age of the children except for participant age. Conclusion: Our results demonstrate social and demographic differences between parents and non-parents receiving MMT. These differences highlight the need to understand necessary additional support for parents such as child support and other necessary therapies. [ABSTRACT FROM AUTHOR]