Benzodiazepine use in medical cannabis authorization adult patients from 2013 to 2021: Alberta, Canada.

BACKGROUND: Benzodiazepines are a class of medications that are being frequently prescribed in Canada but carry significant risk of harm. There has been increasing clinical interest on the potential "sparing effects" of medical cannabis as one strategy to reduce benzodiazepine use. The objective of this study as to examine the association of medical cannabis authorization with benzodiazepine usage between 2013 and 2021 in Alberta, Canada. METHODS: A propensity score matched cohort study with patients on regular benzodiazepine treatment authorized to use medical cannabis compared to controls who do not have authorization for medical cannabis. A total of 9690 medically authorized cannabis patients were matched to controls. To assess the effect of medical cannabis use on daily average diazepam equivalence (DDE), interrupted time series (ITS) analysis was used to assess the change in the trend of DDE in the 12 months before and 12 months after the authorization of medical cannabis. RESULTS: Over the follow-up period after medical cannabis authorization, there was no overall change in the DDE use in authorized medical cannabis patients compared to matched controls (- 0.08 DDE, 95% CI: - 0.41 to 0.24). Likewise, the sensitivity analysis showed that, among patients consuming ≤5 mg baseline DDE, there was no change immediately after medical cannabis authorization compared to controls (level change, - 0.04 DDE, 95% CI: - 0.12 to 0.03) per patient as well as in the month-to-month trend change (0.002 DDE, 95% CI: - 0.009 to 0.12) per patient was noted. CONCLUSIONS: This short-term study found that medical cannabis authorization had minimal effects on benzodiazepine use. Our findings may contribute ongoing evidence for clinicians regarding the potential impact of medical cannabis to reduce benzodiazepine use. HIGHLIGHTS: • Medical cannabis authorization had little to no effect on benzodiazepine usage among patients prescribed regular benzodiazepine treatment in Alberta, Canada. • Further clinical research is needed to investigate the potential impact of medical cannabis as an alternative to benzodiazepine medication.

Generalized Anxiety Disorder 7-Item (GAD-7) Scores in Medically Authorized Cannabis Patients-Ontario and Alberta, Canada.

OBJECTIVES: Despite increasing rates of legalization of medical cannabis worldwide, the current evidence available on its effect on mental health outcomes including anxiety is of mixed results. This study assesses the effect of medical cannabis on generalized anxiety disorder 7-item (GAD-7) scores in adult patients between 2014 and 2019 in Ontario and Alberta, Canada. METHODS: An observational cohort study of adults authorized to use medical cannabis. The GAD-7 was administered at the time of the first visit to the clinic and subsequently over the follow-up time period of up to 3.2 years. Overall changes in GAD-7 scores were computed (mean change) and categorized as: no change (<1 point); improvement; or worsening-over time. RESULTS: A total of 37,303 patients had initial GAD-7 scores recorded and 5,075 (13.6%) patients had subsequent GAD-7 follow-up scores. The average age was 54.2 years (SD 15.7 years), 46.0% were male, and 45.6% noted anxiety symptoms at the baseline. Average GAD-7 scores were 9.11 (SD 6.6) at the baseline and after an average of 282 days of follow-up (SD 264) the average final GAD-7 score recorded was 9.04 (SD 6.6): mean change -0.23 (95% CI, -0.28 to -0.17, t[5,074]: -8.19, p-value <0.001). A total of 4,607 patients (90.8%) had no change in GAD-7 score from their initial to final follow-up, 188 (3.7%) had a clinically significant decrease, and 64 (1.3%) noted a clinically significant increase in their GAD-7 scores. CONCLUSIONS: Overall, there was a statistically significant decrease in GAD-7 scores over time (in particular, in the 6-12-month period). However, this change did not meet the threshold to be considered clinically significant. Thus, we did not detect clinical improvements or detriment in GAD-7 scores in medically authorized cannabis patients. However, future well-controlled clinical trials are needed to fully examine risks or benefits associated with using medical cannabis to treat anxiety conditions.

Substance Use Disorders and Psychoactive Drug Poisoning in Medically Authorized Cannabis Patients: Longitudinal Cohort Study.

OBJECTIVES: Poisoning from psychoactive drugs and substance use disorders (SUD) have been reported among non-medical cannabis users. However, little is known about medical cannabis users and their risk for poisoning and/or development of SUD. This study assessed the risk of emergency department (ED) visits or hospitalization for 1) poisoning by psychoactive drugs and 2) mental/behavioural disorders due to the use of psychoactive drugs and other substances, in medically authorized cannabis patients in Ontario, Canada from 2014-2017. METHODS: A cohort study of adult patients authorized for medical cannabis that were matched to population-based controls. ED visit/hospitalization were assessed with a main diagnostic code for: 1) poisoning by psychoactive drugs; 2) mental and behavioural disorder due to psychoactive drugs or other substance use. Conditional Cox proportional hazards regressions were conducted. RESULTS: 18,653 cannabis patients were matched to 51,243 controls. During a median follow-up of 243 days, the incidence rate for poisoning was 4.71 per 1,000 person-years (95%CI: 3.71-5.99) for cases and 1.73 per 1,000 person-years (95% CI: 1.36-2.19) for controls. The adjusted hazard ratio (aHR) was 2.45 (95%CI: 1.56-3.84). For mental/behavioural disorders, the incident rates were 8.89 (95% CI: 7.47-10.57) and 5.01 (95% CI: 4.36-5.76) in the cannabis and the controls group. The aHR was 2.27 (95%CI: 1.66-3.11). No difference was observed between males and females (P-value for interaction > 0.05). CONCLUSIONS: Our study observed a short-term increased risk of ED visit/hospitalization for poisoning or for mental/behavioural disorders (from use of psychoactive drugs and other substances)- in medically authorized cannabis patients.

Incidence and Predictors of Cannabis-Related Poisoning and Mental and Behavioral Disorders among Patients with Medical Cannabis Authorization: A Cohort Study.

OBJECTIVE: As medical cannabis use increases in North America, establishing its safety profile is a priority. The objective of this study was to assess rates of emergency department (ED) visits and hospitalizations due to poisoning by cannabis, and cannabis-related mental health disorders among medically authorized cannabis patients in Ontario, Canada, between 2014 and 2017. METHODS: This is a retrospective cohort study of patients who received medical cannabis authorization in Ontario, Canada, using data collected in participating cannabis clinics. Outcomes included ED visit/hospitalization with a main diagnosis code for: cannabis/cannabinoid poisoning; and mental/behavioral disorders due to cannabis use. Cox proportional hazard regressions were utilized to analyze the data. RESULTS: From 29,153 patients who received medical authorization, 23,091 satisfied the inclusion criteria. During a median follow-up of 240 days, 14 patients visited the ED or were hospitalized for cannabis poisoning-with an incidence rate of 8.06 per 10,000 person-years (95% CI: 4.8-13.6). A total of 26 patients visited the ED or were hospitalized for mental and behavioral disorders due to cannabis use-with an incidence rate of 15.0 per 10,000 person-years (95% CI: 10.2-22.0). Predictors of cannabis-related mental and behavioral disorders include prior substance use disorders, other mental disorders, age, diabetes, and chronic obstructive pulmonary disease. CONCLUSIONS: The results suggest that the incidence of cannabis poisoning or cannabis-related mental and behavioral disorders was low among patients who were authorized to use cannabis for medical care. Identified predictors can help to target patients with potential risk of the studied outcomes.

Medical cannabis authorization and the risk of cardiovascular events: a longitudinal cohort study.

BACKGROUND: Cannabis is increasingly used for therapeutic purpose. However, its safety profile is not well known. This study assessed the risk of cardiovascular-related emergency department (ED) visit and hospitalization in adult patients authorized to use medical cannabis in Ontario, Canada from 2014 to 2017. METHODS: This is a longitudinal cohort study of patients who received medical cannabis authorization and followed-up in cannabis clinics, matched to population-based controls. The primary outcome was an ED visit or hospitalization for acute coronary syndrome (ACS) or stroke; and secondary outcome was for any cardiovascular event. Conditional Cox proportional hazards regression was used to assess the association between cannabis authorization and risk. RESULTS: 18,653 cannabis patients were matched to 51,243 controls. During a median follow-up of 242 days, the incidence rates for ACS or stroke were 7.19/1000 person-years and 5.67/1000 person-years in the cannabis and controls group, respectively- adjusted hazard ratio (aHR) of 1.44 (95% CI 1.08-1.93). When stratified by sex, the association was only statistically significant among males: aHR 1.77 (1.23-2.56). For the secondary outcome (any CV events), the aHR was 1.47 (1.26-1.72). The aHR among males and females were 1.52 (1.24-1.86) and 1.41 (1.11-1.79), respectively. Tested interaction between cannabis authorization and sex was not significant (p > 0.05). CONCLUSIONS: Medical cannabis authorization was associated with an increased risk of ED visits or hospitalization for CV events including stroke and ACS.

Opioid use in medical cannabis authorization adult patients from 2013 to 2018: Alberta, Canada.

BACKGROUND: The opioid overdose epidemic in Canada and the United States has become a public health crisis - with exponential increases in opioid-related morbidity and mortality. Recently, there has been an increasing body of evidence focusing on the opioid-sparing effects of medical cannabis use (reduction of opioid use and reliance), and medical cannabis as a potential alternative treatment for chronic pain. The objective of this study is to assess the effect of medical cannabis authorization on opioid use (oral morphine equivalent; OME) between 2013 and 2018 in Alberta, Canada. METHODS: All adult patients defined as chronic opioid users who were authorized medical cannabis by their health care provider in Alberta, Canada from 2013 to 2018 were propensity score matched to non-authorized chronic opioid using controls. A total of 5373 medical cannabis patients were matched to controls, who were all chronic opioid users. The change in the weekly average OME of opioid drugs for medical cannabis patients relative to controls was measured. Interrupted time series (ITS) analyses was used to assess the trend change in OME during the 26 weeks (6 months) before and 52 weeks (1 year) after the authorization of medical cannabis among adult chronic opioid users. RESULTS: Average age was 52 years and 54% were female. Patients on low dose opioids (< 50 OME) had an increase in their weekly OME per week (absolute increase of 112.1 OME, 95% CI: 104.1 to 120.3); whereas higher dose users (OME > 100), showed a significant decrease over 6 months (- 435.5, 95% CI: - 596.8 to - 274.2) compared to controls. CONCLUSIONS: This short-term study found that medical cannabis authorization showed intermediate effects on opioid use, which was dependent on initial opioid use. Greater observations of changes in OME appear to be in those patients who were on a high dosage of opioids (OME > 100); however, continued surveillance of patients utilizing both opioids and medical cannabis is warranted by clinicians to understand the long-term potential benefits and any harms of ongoing use.

Predictors of Persistent Postsurgical Pain After Hysterectomy-A Prospective Cohort Study.

STUDY OBJECTIVE: To determine sociodemographic, surgical, and psychologic risk factors, including pain sensitivity, for persistent postsurgical pain (PPSP) after hysterectomy. DESIGN: A prospective cohort study. SETTING: Canadian academic medical center. PATIENTS: Patients (N = 200) who underwent hysterectomy (vaginal, laparoscopic, robotic, or open) between 2013 and 2014. INTERVENTIONS: Participants completed preoperative questionnaires assessing baseline pain scores and psychologic factors, including the Pain Sensitivity Questionnaire, Brief Pain Inventory Interference Items, the Beck Depression Inventory, the Numeric Rating Scale (NRS), and the Pain Catastrophizing Scale. Pain was recorded 1 and 24 hours postoperatively using the NRS. Patients were reassessed at 6 weeks postoperatively and completed the Brief Pain Inventory Interference Items, Patient Global Impression of Change, and the NRS. Patients who reported pain at 6 weeks were reassessed at 12 weeks using the above-mentioned questionnaires. MEASUREMENTS AND MAIN RESULTS: Of 200 study participants, 58 (32%) met the definition for PPSP (NRS ≥ 1 at 12 weeks), and 11 (6.1%) met the definition for moderate to severe postsurgical pain (NRS ≥ 4 at 12 weeks). Risk factors for PPSP included baseline pain scores, depression, pain catastrophizing, uterine mass, open surgical approach, acute postoperative pain, history of chronic pain, and having a hysterectomy due to pain. Multivariate regression analysis revealed that depression, pain catastrophizing, open surgical approach, and acute postoperative pain at 1 hour represent independent predictors of PPSP. Pain sensitivity was not associated with PPSP but was associated with acute and severe acute (NRS≥4) pain at 24 hours. CONCLUSION: Patients at risk for PPSP after hysterectomy can be identified preoperatively using validated questionnaires. This information can be used to guide targeted perioperative interventions to mitigate their risk.

Gaps in evidence for the use of medically authorized cannabis: Ontario and Alberta, Canada.

BACKGROUND: With legal access to medical cannabis in Canada since 2001, there is a need to fully characterize its use at both the individual and population levels. We draw on data from Canada's largest cohort study of medical cannabis to identify the primary reasons for medical cannabis authorization in Canada from 2014 to 2019 in two major provinces: Alberta (AB) and Ontario (ON), and review the extent that evidence supports each indication. METHODS: Self-reported baseline assessments were collected from adult patients in ON (n = 61,835) and AB (n = 3410) who were authorized medical cannabis. At baseline, sociodemographic, primary medical information, and validated clinical questionnaires were completed by patients as part of an individual assessment. Patients' reasons for seeking medical cannabis were compared to published reviews and guidelines to assess the level of evidence supporting medical cannabis use for each condition. RESULTS: Medical cannabis use in both AB and ON was similar in both demographic and reason for authorization. The most common reasons for medical cannabis authorization were: (1) pain (AB = 77%, ON = 76%) primarily due to chronic musculoskeletal, arthritic, and neuropathic pain, (2) mental health concerns (AB = 32.9%, ON = 38.7%) due to anxiety and depression, and (3) sleep problems (AB = 28%, ON = 25%). More than 50 other conditions were identified as reasons for obtaining authorization. CONCLUSION: In both AB and ON, the majority of reasons for medical cannabis authorization are not substantiated by clinical evidence to fully support its efficacy for long-term use. Ongoing epidemiological studies on medical cannabis on these treatments are warranted to fully outline its treatment benefits or risks.

Changes in patient health questionnaire (PHQ-9) scores in adults with medical authorization for cannabis.

BACKGROUND: Legal access to medical cannabis is increasing world-wide. Despite this, there is a lack of evidence surrounding its efficacy on mental health outcomes, particularly, on depression. This study assesses the effect of medical cannabis on Patient Health Questionnaire (PHQ-9) scores in adult patients between 2014 and 2019 in Ontario and Alberta, Canada. METHODS: An observational cohort study of medically authorized cannabis patients in Ontario and Alberta. Overall change in PHQ-9 scores from baseline to follow-up were evaluated (mean change) over a time period of up to 3.2 years. RESULTS: 37,338 patients from the cohort had an initial PHQ-9 score recorded with 5103 (13.7%) patients having follow-up PHQ-9 scores. The average age was 54 yrs. (SD 15.7), 46% male, 50% noted depression at baseline. The average PHQ-9 score at baseline was 10.5 (SD 6.9), following a median follow-up time of 196 days (IQR: 77-451) the average final PHQ-9 score was 10.3 (SD 6.8) with a mean change of - 0.20 (95% CI: - 0.26, - 0.14, p-value < 0.0001). Overall, 4855 (95.1%) had no clinically significant change in their PHQ-9 score following medical cannabis use while 172 (3.4%) reported improvement and 76 (1.5%) reported worsening of their depression symptoms. CONCLUSIONS: Although the majority showed no clinically important changes in PHQ-9 scores, a number of patients showed improvement or deteriorations in PHQ-9 scores. Future studies should focus on the parallel use of screening questionnaires to control for PHQ-9 sensitivity and to explore potential factors that may have attributed to the improvement in scores pre- and post- 3-6 month time period.

Perioperative Pain and Addiction Interdisciplinary Network (PAIN) clinical practice advisory for perioperative management of buprenorphine: results of a modified Delphi process.

Until recently, the belief that adequate pain management was not achievable while patients remained on buprenorphine was the impetus for the perioperative discontinuation of buprenorphine. We aimed to use an expert consensus Delphi-based survey technique to 1) specify the need for perioperative guidelines in this context and 2) offer a set of recommendations for the perioperative management of these patients. The major recommendation of this practice advisory is to continue buprenorphine therapy in the perioperative period. It is rarely appropriate to reduce the buprenorphine dose irrespective of indication or formulation. If analgesia is inadequate after optimisation of adjunct analgesic therapies, we recommend initiating a full mu agonist while continuing buprenorphine at some dose. The panel believes that before operation, physicians must distinguish between buprenorphine use for chronic pain (weaning/conversion from long-term high-dose opioids) and opioid use disorder (OUD) as the primary indication for buprenorphine therapy. Patients should ideally be discharged on buprenorphine, although not necessarily at their preoperative dose. Depending on analgesic requirements, they may be discharged on a full mu agonist. Overall, long-term buprenorphine treatment retention and harm reduction must be considered during the perioperative period when OUD is a primary diagnosis. The authors recognise that inter-patient variability will require some individualisation of clinical practice advisories. Clinical practice advisories are largely based on lower classes of evidence (level 4, level 5). Further research is required in order to implement meaningful changes in practitioner behaviour for this patient group.

The prescription of medical cannabis by a transitional pain service to wean a patient with complex pain from opioid use following liver transplantation: a case report.

PURPOSE: The purpose of this case report is to describe a patient with a preoperative complex pain syndrome who underwent liver transplantation and was able to reduce his opioid consumption significantly following the initiation of treatment with medical cannabis. CLINICAL FEATURES: A 57-yr-old male with a history of hepatitis C cirrhosis underwent liver transplantation. Preoperatively, he was taking hydromorphone 2-8 mg⋅day(-1) for chronic abdominal pain. Postoperatively, he was given intravenous patient-controlled analgesia through which he received hydromorphone 30 mg⋅day(-1). Our multidisciplinary Transitional Pain Service was involved with managing his moderate to severe acute postsurgical pain in hospital and continued with weaning him from opioid medications after discharge. It was difficult to wean the patient from opioids, and he was subsequently given medical cannabis at six weeks postoperatively with remarkable effect. By the fifth postoperative month, his use of opioids had tapered to 6 mg⋅day(-1) of hydromorphone, and his functional status was excellent on this regimen. CONCLUSION: Reductions in opioid consumption were achieved with the administration of medical cannabis in a patient with acute postoperative pain superimposed on a chronic pain syndrome and receiving high doses of opioids. Concurrent benefits of initiating medical cannabis may include improvements in pain profile and functional status along with reductions in opioid-related side effects. This highlights the potential for medical cannabis as an adjunct medication for weaning patients from opioid use.

Impact of self-management interventions on stable angina symptoms and health-related quality of life: a meta-analysis.

BACKGROUND: Chronic stable angina (CSA) has a major negative impact on health-related quality of life (HRQL) including poor general health status, psychological distress, and inability to self-manage. METHODS: We used meta-analysis to assess the effectiveness of self-management interventions for improving stable angina symptoms, HRQL and psychological well-being. Nine trials, involving 1,282 participants in total, were included. We used standard inverse-variance random-effects meta-analysis to combine the trials. Heterogeneity between trials was evaluated using chi-square tests for the tau-squared statistic and quantified using the I2 statistic. RESULTS: There was significant improvement in the frequency of angina symptoms (Seattle Angina Questionnaire [SAQ], symptom diary) across trials, standardized mean difference (SMD): 0.30 (95% Confidence interval [CI] 0.14, 0.47), as well as reduction in the use of sublingual (SL) nitrates, SMD: -0.49 (95% CI -0.77, -0.20). Significant improvements for physical limitation (SAQ), SMD: 0.38 (95% CI 0.20, 0.55) and depression scores (Hospital Anxiety and Depression Scale), SMD: -1.38 (95% CI -2.46, -0.30) were also found. The impact of SM on anxiety was uncertain due to statistical heterogeneity across trials for this outcome, I2 = 98%. SM did not improve other HRQL dimensions including angina stability, disease perception, and treatment satisfaction. CONCLUSIONS: SM interventions significantly improve angina frequency and physical limitation; they also decrease the use of SL nitrates and improve depression in some cases. Further work is needed to make definitive conclusions about the impact of SM on cardiac-specific anxiety.

Ultrasound-guided placement of a paddle lead onto peripheral nerves: surgical anatomy and methodology.

OBJECTIVES: Implanted peripheral nerve stimulation is one of the earliest developed methods of neuromodulation for the treatment of chronic neuropathic pain. It is traditionally performed by surgical exposure and implantation of a paddle lead. Ultrasound-guided percutaneous placement of cylindrical leads has been proposed as an alternative. However, those leads are fragile and prone to migration. Minimally invasive paddle lead implantation may improve long-term results while minimizing surgical insult. A feasibility laboratory study was performed. MATERIALS AND METHODS: Ultrasound-guided placements of a narrow paddle lead were performed in the upper and lower extremities of a human cadaver. Ultrasonography was used to record the lead position relative to the target nerves. Dissections were performed, and digital photography was completed. Anatomic images were analyzed. RESULTS: All experiments were successfully accomplished. Although ultrasound localization of the upper extremity nerves was straightforward and clear, all procedural steps were technically easier at the lower extremity. For the latter, fewer attempts were required to maintain the lead in the desired tissue plane. Ultrasound revealed an acoustic shadowing of the underlying nerves in both the short- and long-axis views by the inserted lead. All dissections revealed a parallel to the nerve lead placement with at least four contacts facing the nerve. The lead appeared to be more mechanically stable at the lower extremity. CONCLUSIONS: This anatomic study confirmed technical feasibility of percutaneous placement of a narrow paddle-type lead for the peripheral nerve stimulation that may potentially improve stimulation and reduce migrations.

Medical cannabis authorization and risk of emergency department visits and hospitalization due to psychotic disorders: A propensity score-matched cohort study.

Despite evidence showing that recreational cannabis use is associated with a higher risk of psychotic disorders, this risk has not been well characterized for patients using medical cannabis. Therefore, this study assessed the risk of emergency department (ED) visits and hospitalization for psychotic disorders (the study outcome) among adult patients authorized to use medical cannabis. We performed a retrospective cohort study on patients authorized to use medical cannabis in a group of Ontario cannabis clinics between 2014 and 2019. Using clinical and health administrative data, each patient was matched by propensity scores to up to 3 population-based controls. Conditional Cox proportional hazards regressions were used to assess the risk. Among 54,006 cannabis patients matched to 161,265 controls, 39 % were aged ≤50 years, and 54 % were female. Incidence rates for psychotic disorders were 3.00/1000 person-years (95%CI: 2.72-3.32) in the cannabis group and 1.88/1000 person-years (1.75-2.03) in the control group. A significant association was observed, with an adjusted hazard ratio of 1.38 (95%CI: 1.19-1.60) in the total sample and 1.63 (1.40-1.91) in patients without previous psychotic disorders. The results suggest that cannabis authorization should include a benefit-risk assessment of psychotic disorders to minimize the risk of events requiring emergency attention.

Risk of depressive disorders associated with medical cannabis authorization: A propensity score matched cohort study.

There is an increase in the medical use of cannabis. However, the safety of medical cannabis, particularly for mental health conditions, has not yet been clearly established. Thus, this study assessed the risk of emergency department (ED) visits and hospitalization for depressive disorders among medical cannabis users. We conducted a retrospective longitudinal cohort study of patients who received medical authorization to use cannabis from 2014 to 2019 in Ontario, matched (1:3 ratio) to population-based controls using propensity scores. Conditional Cox regressions were used to assess the association between cannabis authorization and the outcome. A total of 54,006 cannabis-authorized patients and 161,265 controls were analyzed. Approximately 39% were aged under 50 years, 54% were female, and 16% had a history of anxiety or mood disorders. The adjusted hazard ratio (aHR) for depressive disorders was 2.02 (95%CI: 1.83-2.22). The aHR was 2.23 (1.95-2.55) among subjects without prior mental health disorders. The interaction between sex (or age) and exposure was not significant. In conclusion, medical cannabis authorization was associated with an increased risk of depressive disorders. This finding highlights the need for a careful risk-benefit assessment when authorizing cannabis, particularly for patients who seek cannabis to treat a depressive condition.

Cohort study of medical cannabis authorization and motor vehicle crash-related healthcare visits in 2014-2017 in Ontario, Canada.

BACKGROUND: With increasing numbers of countries/jurisdictions legalizing cannabis, cannabis impaired driving has become a serious public health concern. Despite substantive research linking cannabis use with higher rates of motor vehicle crashes (MVC), there is an absence of conclusive evidence linking MVC risk with medical cannabis use. In fact, there is no clear understanding of the impact of medical cannabis use on short- and long-term motor vehicle-related healthcare visits. This study assesses the impact of medical cannabis authorization on motor vehicle-related health utilization visits (hospitalizations, ambulatory care, emergency department visits, etc) between 2014 and 2017 in Ontario, Canada. METHODS: A matched cohort study was conducted on patients authorized to use medical cannabis and controls who did not receive authorization for medical cannabis - in Ontario, Canada. Overall, 29,153 adult patients were identified and subsequently linked to the administrative databases of the Ontario Ministry of Health, providing up to at least 6 months of longitudinal follow-up data following the initial medical cannabis consultation. Interrupted time series analyses was conducted to evaluate the change in rates of healthcare utilization as a result of MVC 6 months before and 6 months after medical cannabis authorization. RESULTS: Over the 6-month follow-up period, MVC-related visits in medical cannabis patients were 0.50 visits/10000 patients (p = 0.61) and - 0.31 visits/10000 patients (p = 0.64) for MVC-related visits in controls. Overall, authorization for medical cannabis was associated with an immediate decrease in MVC-related visits of - 2.42 visits/10000 patients (p = 0.014) followed by a statistically significant increased rate of MVC-related visits (+ 0.89 events/10,000 in those authorized medical cannabis) relative to controls in the period following their authorization(p = 0.0019). Overall, after accounting for both the immediate and trend effects, authorization for medical cannabis was associated with an increase of 2.92 events/10,000 (95%CI 0.64 to 5.19) over the entire follow-up period. This effect was largely driven by MVC-related emergency department visits (+ 0.80 events/10,000, p < 0.001). CONCLUSIONS: Overall, there was an association between medical cannabis authorization and healthcare utilization, at the population level, in Ontario, Canada. These findings have public health importance and patients and clinicians should be fully educated on the potential risks. Continued follow-up of medically authorized cannabis patients is warranted to fully comprehend long-term impact on motor vehicle crash risk.

Cohort study of medical cannabis authorisation and healthcare utilisation in 2014-2017 in Ontario, Canada.

BACKGROUND: The impact of medical cannabis on healthcare utilisation between 2014 and 2017 in Ontario, Canada. With cannabis legalisation in Canada and some states in the USA, high-quality longitudinal cohort research studies are of urgent need to assess the impact of cannabis use on healthcare utilisation. METHODS: A matched cohort study of 9925 medical cannabis authorised adult patients (inhaled (smoked or vaporised) or orally consumed (oils)) at specialised cannabis clinics, and inclusion of 17 732 controls (not authorised) between 24 April 2014 and 31 March 2017 from Ontario, Canada. Interrupted time series and multivariate Poisson regression analyses were conducted. Medical cannabis impact on healthcare utilisation was measured over 6 months: all-cause physician visits, all-cause hospitalisation, ambulatory care sensitive conditions (ACSC)-related hospitalisations, all-cause emergency department (ED) visits and ACSC-related ED visits. RESULTS: For medical cannabis patients compared with controls, there was an initial (within the first month) increase in physician visits (additional 4330 visits per 10 000 patients). However, a numerical reduction was noted over the 6-month follow-up, and no statistical difference was observed (p=0.126). Likewise, in hospitalisations and ACSC ED visits, there was an initial increase (44 per 10 000 people, p<0.05) but no statistical difference after follow-up (p=0.34). Conversely, no initial increase in all-cause ED visits was observed with a slight decrease (19 visits per 10 000 patients, p=0.014) in follow-up. CONCLUSIONS: An initial increase (within first month) in healthcare utilisation may be expected among medical cannabis users that appears to wane over time. Proactive follow-up of patients using medical cannabis is warranted to minimise initial risks to patients and actively assess potential benefits/harms of ongoing use.

Cannabis and cannabinoids in cancer pain management.

PURPOSE OF REVIEW: An increasing number of patients are turning to cannabis and cannabinoids for management of their palliative and nonpalliative cancer pain and other cancer-related symptoms. Canadians have a legal framework for access to medical cannabis, which provides a unique perspective in a setting lacking robust clinical evidence. This review seeks to delineate the role of cannabis and cannabinoids in cancer pain management and offers insight into the Canadian practice. RECENT FINDINGS: A cohort study using nabiximols on advanced cancer pain in patients already optimized on opioids, over 3 weeks, demonstrated improved average pain score. A large observational study of cancer patients using cannabis over 6 months demonstrated a decreased number of patients with severe pain and decreased opioid use, whereas the number of patients reporting good quality of life increased. SUMMARY: Good preclinical animal data and a large body of observational evidence point to the potential efficacy of cannabinoids for cancer pain management. However, there are relatively weak data pointing to clinical efficacy from clinical trial data to date. In Canada, the burgeoning cannabis industry has driven the population to embrace a medicine before clinical evidence. There remains a need for high-quality randomized controlled trials to properly assess the effectiveness and safety of medical cannabis, compared with placebo and standard treatments for cancer-related symptoms.

Validation of the Imperial College Surgical Assessment Device (ICSAD) for labour epidural placement.

PURPOSE: Technical proficiency in anesthesia has historically been determined subjectively. The purpose of this study was to establish the construct validity for the Imperial College Surgical Assessment Device (ICSAD), a measure of hand motion efficiency, as an objective assessment tool for technical skill performance, by examining its ability to distinguish between operators of different levels of experience performing a labour epidural. Concurrent validity for the ICSAD was investigated by comparison to a validated task specific checklist (CL) and global rating scale (GRS). METHODS: A single blinded, prospective, controlled study design compared three groups of subjects: novice residents (<30 epidurals), experienced residents (>100 epidurals), and staff anesthesiologists (>500 epidurals). Performance was measured using the ICSAD (number of movements, path length, time) and scores from a CL and GRS graded by examiners blinded to the level of training. Data were analyzed by multivariate analysis of variance (MANOVA). RESULTS: Twenty-nine subjects were recruited. Novice residents had longer path lengths compared to experienced residents (P = 0.031) and staff anesthesiologists (P = 0.0004), made more movements (P = 0.012) and took more time than staff (P = 0.009). Novice residents scored significantly worse on the GRS compared to experienced residents (P = 0.029) and staff (P = 0.01) and had significantly lower CL scores compared to staff (P = 0.003). CONCLUSIONS: Construct and concurrent validity for the ICSAD was established for a regional anesthesia technique by demonstrating that it can distinguish between operators of different levels of experience and by comparing it to the current standards of technical skill assessment.

The Impact of Perioperative Cannabis Use: A Narrative Scoping Review.

As countries progressively embrace the legalization of both medicinal and recreational cannabis, there remains a significant knowledge gap when it comes to the perioperative uses of cannabis, as well as the management of cannabis users. This review summarizes the information available on the subject based on existing published studies. Articles outlining the physiological changes occurring in the human body during acute and chronic use of cannabis (outside the context of anesthesia) are also taken into consideration as understanding these changes allows a more calculated approach to better anticipate patients' needs in the perioperative setting. Common questions facing the anesthesiologist at each phase of the perioperative period will be addressed and a systematic approach to the effect of cannabinoids on various organ systems will also be presented. Issues unique to cannabis use such as cannabis withdrawal syndrome and alterations in post-operative pain processing will also be discussed. To date, the number of studies available for guidance is small and study designs are markedly heterogenous, if not limited, making conclusions challenging. While the currently available information can assist in making decisions, further studies of larger scale are eagerly anticipated to help guide future patient care.