Comparative Analysis of Instrumental Variables on the Assignment of Buprenorphine/Naloxone or Methadone for the Treatment of Opioid Use Disorder.

Background: Instrumental variable (IV) analysis provides an alternative set of identification assumptions in the presence of uncontrolled confounding when attempting to estimate causal effects. Our objective was to evaluate the suitability of measures of prescriber preference and calendar time as potential IVs to evaluate the comparative effectiveness of buprenorphine/naloxone versus methadone for treatment of opioid use disorder (OUD).

Methods: Using linked population-level health administrative data, we constructed five IVs: prescribing preference at the individual, facility, and region levels (continuous and categorical variables), calendar time, and a binary prescriber's preference IV in analyzing the treatment assignment-treatment discontinuation association using both incident-user and prevalent-new-user designs.

COVID-19 vaccination mandates and vaccine uptake.

We evaluate the impact of government-mandated proof of vaccination requirements for access to public venues and non-essential businesses on COVID-19 vaccine uptake. We find that the announcement of a mandate is associated with a rapid and significant surge in new vaccinations (a more than 60% increase in weekly first doses), using the variation in the timing of these measures across Canadian provinces in a difference-in-differences approach. Time-series analysis for each province and for France, Italy and Germany corroborates this finding.

The effect of a methadone reformulation on opioid agonist treatment outcomes: A population-based study in British Columbia, Canada, 2013-14.

Introduction: The province of British Columbia, Canada, changed the existing oral anhydrous methadone solution to a 10-times more concentrated pre-mixed solution, Methadose®, on February 1, 2014. We aimed to assess the immediate effects of the methadone reformulation on missed doses, days off methadone, changes in medication dosing and dispensations of opioids for pain, and hospitalizations and mortality among all people receiving treatment at or near the time of the change.

Methods: We conducted a population-based retrospective cohort study including all individuals receiving at least one methadone dispensation in the 12 months prior to the study period.

Face masks, public policies and slowing the spread of COVID-19: Evidence from Canada.

We estimate the impact of indoor face mask mandates and other non-pharmaceutical interventions (NPI) on COVID-19 case growth in Canada. Mask mandate introduction was staggered from mid-June to mid-August 2020 in the 34 public health regions in Ontario, Canada's largest province by population. Using this variation, we find that mask mandates are associated with a 22 percent weekly reduction in new COVID-19 cases, relative to the trend in absence of mandate.

Supplier-induced demand for newborn treatment: evidence from Japan.

We estimate the degree of supplier-induced demand for newborn treatment by exploiting changes in reimbursement arising from the introduction of the partial prospective payment system (PPS) in Japan. Under the partial PPS, neonatal intensive care unit (NICU) utilization became relatively more profitable than other procedures, since it was excluded from prospective payments. We find that hospitals have responded to PPS adoption by increasing NICU utilization and by more frequently manipulating infants' reported birth weights which in large part determine their maximum allowable stay in the NICU.