Impact of coordinated care on adherence to antihypertensive medicines among adults experiencing polypharmacy in Australia.

BACKGROUND: Adherence to antihypertensives is key for blood pressure control. Most people with hypertension have several comorbidities and require multiple medicines, leading to complex care pathways. Strategies for coordinating medicine use can improve adherence, but cumulative benefits of multiple strategies are unknown. METHODS: Using dispensing claims for a 10% sample of eligible Australians, we identified adult users of antihypertensives during July 2018-June 2019 who experienced polypharmacy (≥5 unique medicines). We measured medicine use reflecting coordinated medicine management in 3 months before and including first observed dispensing, including: use of simple regimens for each cardiovascular medicine; prescriber continuity; and coordination of dispensings at the pharmacy. We measured adherence (proportion of days covered) to antihypertensive medicines in the following 12 months, and used logistic regression to assess independent associations and interactions of adherence with these measures of care. RESULTS: We identified 202 708 people, of which two-thirds (66.6%) had simple cardiovascular medicine regimens (one tablet per day for each medicine), two-thirds (63.3%) were prescribed >75% of medicines from the same prescriber, and two-thirds (65.5%) filled >50% of their medicine on the same day. One-third (28.4%) of people experienced all three measures of coordinated care. Although all measures were significantly associated with higher adherence, adherence was greatest among people experiencing all three measures (odds ratio = 1.63; 95% confidence interval: 1.55-1.72). This interaction was driven primarily by effects of prescriber continuity and dispensing coordination. CONCLUSIONS: Coordinating both prescribing and dispensing of medicines can improve adherence to antihypertensives, which supports strategies consolidating both prescribing and supply of patients' medicines.

OpenSAFELY: The impact of COVID-19 on azathioprine, leflunomide and methotrexate monitoring, and factors associated with change in monitoring rate.

AIMS: The COVID-19 pandemic created unprecedented pressure on healthcare services. This study investigates whether disease-modifying antirheumatic drug (DMARD) safety monitoring was affected during the COVID-19 pandemic. METHODS: A population-based cohort study was conducted using the OpenSAFELY platform to access electronic health record data from 24.2 million patients registered at general practices using TPP's SystmOne software. Patients were included for further analysis if prescribed azathioprine, leflunomide or methotrexate between November 2019 and July 2022. Outcomes were assessed as monthly trends and variation between various sociodemographic and clinical groups for adherence with standard safety monitoring recommendations. RESULTS: An acute increase in the rate of missed monitoring occurred across the study population (+12.4 percentage points) when lockdown measures were implemented in March 2020. This increase was more pronounced for some patient groups (70-79 year-olds: +13.7 percentage points; females: +12.8 percentage points), regions (North West: +17.0 percentage points), medications (leflunomide: +20.7 percentage points) and monitoring tests (blood pressure: +24.5 percentage points). Missed monitoring rates decreased substantially for all groups by July 2022. Consistent differences were observed in overall missed monitoring rates between several groups throughout the study. CONCLUSION: DMARD monitoring rates temporarily deteriorated during the COVID-19 pandemic. Deterioration coincided with the onset of lockdown measures, with monitoring rates recovering rapidly as lockdown measures were eased. Differences observed in monitoring rates between medications, tests, regions and patient groups highlight opportunities to tackle potential inequalities in the provision or uptake of monitoring services. Further research should evaluate the causes of the differences identified between groups.

The impact of COVID-19 on medication reviews in English primary care. An OpenSAFELY-TPP analysis of 20 million adult electronic health records.

AIMS: The COVID-19 pandemic caused significant disruption to routine activity in primary care. Medication reviews are an important primary care activity ensuring safety and appropriateness of prescribing. A disruption could have significant negative implications for patient care. Using routinely collected data, our aim was first to describe codes used to record medication review activity and then to report the impact of COVID-19 on the rates of medication reviews. METHODS: With the approval of NHS England, we conducted a cohort study of 20 million adult patient records in general practice, in-situ using the OpenSAFELY platform. For each month, between April 2019 and March 2022, we report the percentage of patients with a medication review coded monthly and in the previous 12 months with breakdowns by regional, clinical and demographic subgroups and those prescribed high-risk medications. RESULTS: In April 2019, 32.3% of patients had a medication review coded in the previous 12 months. During the first COVID-19 lockdown, monthly activity decreased (-21.1% April 2020), but the 12-month rate was not substantially impacted (-10.5% March 2021). The rate of structured medication review in the last 12 months reached 2.9% by March 2022, with higher percentages in high-risk groups (care home residents 34.1%, age 90+ years 13.1%, high-risk medications 10.2%). The most used medication review code was Medication review done 314530002 (59.5%). CONCLUSIONS: There was a substantial reduction in the monthly rate of medication reviews during the pandemic but rates recovered by the end of the study period. Structured medication reviews were prioritized for high-risk patients.

Quality use of publicly subsidised tapentadol in Australia: a population-based analysis.

BACKGROUND: Sustained-release (SR) tapentadol was listed on Australia's Pharmaceutical Benefits Scheme (PBS) in 2014 for chronic severe pain requiring long-term opioid treatment. Dispensings have increased since listing despite declining trends in other PBS-listed opioids. Preferential prescribing of SR opioids may increase the risk of dependence and accidental overdose, particularly when used to treat acute pain. AIMS: To explore the quality use of publicly subsidised tapentadol in Australia. METHODS: We examined annual initiation rates and patterns of use of tapentadol (SR) in the dispensing records of a 10% random sample of PBS-eligible Australians (2014-2021). We used national tapentadol sales data to assess the proportion of sales attributable to the PBS. RESULTS: Tapentadol initiation increased from 2014, peaking at 7.5/1000 adult population in 2019 before declining to 5.3/1000 in 2021. We identified 63 766 new users between 2014 and 2020, of whom 92.8% discontinued in the first year following initiation, 58.0% had only a single dispensing and 34.3% had no other opioids dispensed in the 3 months before or after initiation. 27.8% of new users were dispensed tapentadol on the same day as potentially interacting medicines. There was a sustained drop in the proportion of sales attributable to the PBS from June 2020 onwards, from an average of 69.1%, to 63.9% of pack sales. CONCLUSIONS: Patterns of use suggest tapentadol (SR) is generally used for short duration. Although most tapentadol sold in Australia is subsidised, there is evidence of a shift towards private sales.

Comparative Risk of Major Congenital Malformations With Antiseizure Medication Combinations vs Valproate Monotherapy in Pregnancy.

BACKGROUND AND OBJECTIVES: Valproate should be avoided in pregnancy, but it is the most effective drug for generalized epilepsies. Alternative treatment may require combinations of other drugs. Our objectives were to describe first trimester use of antiseizure medication (ASM) combinations that are relevant alternatives to valproate and determine whether specific combinations were associated with a lower risk of major congenital malformations (MCM) compared with valproate monotherapy. METHODS: We conducted a population-based cohort study using linked national registers from Denmark, Finland, Iceland, Norway, and Sweden and administrative health care data from the United States and New South Wales, Australia. We described first trimester use of ASM combinations among pregnant people with epilepsy from 2000 to 2020. We compared the risk of MCM after first trimester exposure to ASM combinations vs valproate monotherapy and low-dose valproate plus lamotrigine or levetiracetam vs high-dose valproate (≥1,000 mg/d). We used log-binomial regression with propensity score weights to calculate adjusted risk ratios (aRRs) and 95% CIs for each dataset. Results were pooled using fixed-effects meta-analysis. RESULTS: Among 50,905 pregnancies in people with epilepsy identified from 7.8 million total pregnancies, 788 used lamotrigine and levetiracetam, 291 used lamotrigine and topiramate, 208 used levetiracetam and topiramate, 80 used lamotrigine and zonisamide, and 91 used levetiracetam and zonisamide. After excluding pregnancies with use of other ASMs, known teratogens, or a child diagnosed with MCM of infectious or genetic cause, we compared 587 exposed to lamotrigine-levetiracetam duotherapy and 186 exposed to lamotrigine-topiramate duotherapy with 1959 exposed to valproate monotherapy. Pooled aRRs were 0.41 (95% CI 0.24-0.69) and 1.26 (0.71-2.23), respectively. Duotherapy combinations containing low-dose valproate were infrequent, and comparisons with high-dose valproate monotherapy were inconclusive but suggested a lower risk for combination therapy. Other combinations were too rare for comparative safety analyses. DISCUSSION: Lamotrigine-levetiracetam duotherapy in first trimester was associated with a 60% lower risk of MCM than valproate monotherapy, while lamotrigine-topiramate was not associated with a reduced risk. Duotherapy with lamotrigine and levetiracetam may be favored to treat epilepsy in people with childbearing potential compared with valproate regarding MCM, but whether this combination is as effective as valproate remains to be determined. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that in people with epilepsy treated in the first trimester of pregnancy, the risk of major congenital malformations is lower with lamotrigine-levetiracetam duotherapy than with valproate alone, but similar with lamotrigine-topiramate.

Comparative effectiveness of nirmatrelvir/ritonavir versus sotrovimab and molnupiravir for preventing severe COVID-19 outcomes in non-hospitalised high-risk patients during Omicron waves: observational cohort study using the OpenSAFELY platform.

Background: Timely evidence of the comparative effectiveness between COVID-19 therapies in real-world settings is needed to inform clinical care. This study aimed to compare the effectiveness of nirmatrelvir/ritonavir versus sotrovimab and molnupiravir in preventing severe COVID-19 outcomes in non-hospitalised high-risk COVID-19 adult patients during Omicron waves. Methods: With the approval of NHS England, we conducted a real-world cohort study using the OpenSAFELY-TPP platform. Patient-level primary care data were obtained from 24 million people in England and were securely linked with data on COVID-19 infection and therapeutics, hospital admission, and death, covering a period where both nirmatrelvir/ritonavir and sotrovimab were first-line treatment options in community settings (February 10, 2022-November 27, 2022). Molnupiravir (third-line option) was used as an exploratory comparator to nirmatrelvir/ritonavir, both of which were antivirals. Cox proportional hazards model stratified by area was used to compare the risk of 28-day COVID-19 related hospitalisation/death across treatment groups. Findings: A total of 9026 eligible patients treated with nirmatrelvir/ritonavir (n = 5704) and sotrovimab (n = 3322) were included in the main analysis. The mean age was 52.7 (SD = 14.9) years and 93% (8436/9026) had three or more COVID-19 vaccinations. Within 28 days after treatment initiation, 55/9026 (0.61%) COVID-19 related hospitalisations/deaths were observed (34/5704 [0.60%] treated with nirmatrelvir/ritonavir and 21/3322 [0.63%] with sotrovimab). After adjusting for demographics, high-risk cohort categories, vaccination status, calendar time, body mass index and other comorbidities, we observed no significant difference in outcome risk between nirmatrelvir/ritonavir and sotrovimab users (HR = 0.89, 95% CI: 0.48-1.63; P = 0.698). Results from propensity score weighted model also showed non-significant difference between treatment groups (HR = 0.82, 95% CI: 0.45-1.52; P = 0.535). The exploratory analysis comparing nirmatrelvir/ritonavir users with 1041 molnupiravir users (13/1041 [1.25%] COVID-19 related hospitalisations/deaths) showed an association in favour of nirmatrelvir/ritonavir (HR = 0.45, 95% CI: 0.22-0.94; P = 0.033). Interpretation: In routine care of non-hospitalised high-risk adult patients with COVID-19 in England, no substantial difference in the risk of severe COVID-19 outcomes was observed between those who received nirmatrelvir/ritonavir and sotrovimab between February and November 2022, when Omicron subvariants BA.2, BA.5, or BQ.1 were dominant. Funding: UK Research and Innovation, Wellcome Trust, UK Medical Research Council, National Institute for Health and Care Research, and Health Data Research UK.

Five-Year Trajectories of Prescription Opioid Use.

Importance: There are known risks of using opioids for extended periods. However, less is known about the long-term trajectories of opioid use following initiation. Objective: To identify 5-year trajectories of prescription opioid use, and to examine the characteristics of each trajectory group. Design, Setting, and Participants: This population-based cohort study conducted in New South Wales, Australia, linked national pharmaceutical claims data to 10 national and state data sets to determine sociodemographic characteristics, clinical characteristics, drug use, and health services use. The cohort included adult residents (aged ≥18 years) of New South Wales who initiated a prescription opioid between July 1, 2003, and December 31, 2018. Statistical analyses were conducted from February to September 2022. Exposure: Dispensing of a prescription opioid, with no evidence of opioid dispensing in the preceding 365 days, identified from pharmaceutical claims data. Main Outcomes and Measures: The main outcome was the trajectories of monthly opioid use over 60 months from opioid initiation. Group-based trajectory modeling was used to classify these trajectories. Linked health care data sets were used to examine characteristics of individuals in different trajectory groups. Results: Among 3 474 490 individuals who initiated a prescription opioid (1 831 230 females [52.7%]; mean [SD] age, 49.7 [19.3] years), 5 trajectories of long-term opioid use were identified: very low use (75.4%), low use (16.6%), moderate decreasing to low use (2.6%), low increasing to moderate use (2.6%), and sustained use (2.8%). Compared with individuals in the very low use trajectory group, those in the sustained use trajectory group were older (age ≥65 years: 22.0% vs 58.4%); had more comorbidities, including cancer (4.1% vs 22.2%); had increased health services contact, including hospital admissions (36.9% vs 51.6%); had higher use of psychotropic (16.4% vs 42.4%) and other analgesic drugs (22.9% vs 47.3%) prior to opioid initiation, and were initiated on stronger opioids (20.0% vs 50.2%). Conclusions and relevance: Results of this cohort study suggest that most individuals commencing treatment with prescription opioids had relatively low and time-limited exposure to opioids over a 5-year period. The small proportion of individuals with sustained or increasing use was older with more comorbidities and use of psychotropic and other analgesic drugs, likely reflecting a higher prevalence of pain and treatment needs in these individuals.

Five healthcare trajectories in the year before suicide and what they tell us about opportunities for prevention: a population-level case series study.

Background: Suicide prevention requires a shift from relying on an at-risk individual to engage with the healthcare system. Understanding patterns of healthcare engagement by people who have died by suicide may provide alternative directions for suicide prevention. Methods: This is a population-based case-series study of all suicide decedents (n = 3895) in New South Wales (NSW), Australia (2013-2019), with linked coronial, health services and medicine dispensing data. Healthcare trajectories were identified using a k-means longitudinal 3d analysis, based on the number and type of healthcare contacts in the year before death. Characteristics of each trajectory were described. Findings: Five trajectories of healthcare utilisation were identified: (A) none or low (n = 2598, 66.7%), (B) moderate, predominantly for physical health (n = 601, 15.4%), (C) moderate, with high mental health medicine use (n = 397, 10.2%), (D) high, predominantly for physical health (n = 206, 5.3%) and E) high, predominantly for mental health (n = 93, 2.4%). Given that most decedents belonged to Trajectory A this suggests a great need for suicide preventive interventions delivered in the community, workplace, schools or online. Trajectories B and D might benefit from opioid dispensing limits and access to psychological pain management. Trajectory C had high mental health medicine use, indicating that the time that medicines are prescribed or dispensed are important touchpoints. Trajectory E had high mental health service predominantly delivered by psychiatrists and community mental health, but limited psychologist use. Interpretation: Although most suicide decedents made at least one healthcare contact in the year before death, contact frequency was overall very low. Given the characteristics of this group, useful access points for such intervention could be delivered through schools and workplaces, with a focus on alcohol and drug intervention alongide suicide awareness. Funding: Australia's National Health and Medical Research Council.

Substances Detected During Coroner Postmortem Toxicology Analyses in Poisoning- and Nonpoisoning-Related Suicides.

Importance: Determining the association between drug use and suicide is complicated but can help to inform targeted suicide prevention strategies. Objective: To examine the substances prevalent in poisoning- and nonpoisoning-related suicides in Australia. Design, Setting, and Participants: This was a multiple-year, cross-sectional study of suicides from July 2013 to October 2019 in Australia with toxicology data available in a national coronial database. The cause of death was classified as poisoning related if any type of poisoning was determined by the coroner to contribute to the cause of death. Prevalence ratios (PRs) were calculated to compare substance detection in poisoning- vs nonpoisoning-related suicides. Data were analyzed from October 2021 to April 2023. Exposures: All substances detected in decedents at the time of death according to toxicology reports were recorded. Main Outcome(s) and Measure(s): The most common individual substances and substance classes were identified. From these, blood concentrations of substances of interest were analyzed, and the most commonly occurring combinations of substance classes were listed. Results: Toxicology was performed on 13 664 suicide decedents (median [IQR] age, 44 [31-57] years; 10 350 male [76%]). From these, 3397 (25%) were poisoning-related suicides (median [IQR] age, 50 [38-63] years; 2124 male [63%]). The remainder were classified as nonpoisoning-related suicides (median [IQR] age, 42 [29-55] years; 8226 male [80%]). PRs for common medicine classes being detected in poisoning-related suicides compared with nonpoisoning-related suicides were as follows: antidepressants (PR, 1.63; 95% CI, 1.54-1.73), benzodiazepines (PR, 2.01; 95% CI, 1.90-2.13), nonopioid analgesics/anti-inflammatory drugs (PR, 1.88; 95% CI, 1.78-2.00), and opioids (PR, 2.72; 95% CI, 2.58-2.87). Alcohol (as ethanol ≥0.03 g/100 mL) was almost equally prevalent in poisoning- and nonpoisoning-related deaths (PR, 1.07; 95% CI, 1.01-1.14), whereas amphetamines (PR, 0.68; 95% CI, 0.61-0.77) and cannabinoids (PR, 0.67; 95% CI, 0.60-0.74) were detected more often in nonpoisoning-related suicides. Combinations of multiple sedative agents in poisoning-related suicides were common. Conclusions and Relevance: Both poisoning- and nonpoisoning-related suicide deaths featured a high prevalence of psychotropic medicines or potential intoxication, which suggests the association of suicide with poor mental health and substance misuse. Findings suggest that substances with a high involvement in poisoning-related suicides should be prescribed cautiously, including antidepressants that are toxic in overdose, sedatives, opioids, and potentially lethal combinations.

Persistence and Adherence to Cardiovascular Medicines in Australia.

Background The burden of cardiovascular disease is increasing, with many people treated for multiple cardiovascular conditions. We examined persistence and adherence to medicines for cardiovascular disease treatment or prevention in Australia. Methods and Results Using national dispensing claims for a 10% random sample of people, we identified adults (≥18 years) initiating antihypertensives, statins, oral anticoagulants, or antiplatelets in 2018. We measured persistence to therapy using a 60-day permissible gap, and adherence using the proportion of days covered up to 3 years from initiation, and from first to last dispensing. We reported outcomes by age, sex, and cardiovascular multimedicine use. We identified 83 687 people initiating antihypertensives (n=37 941), statins (n=34 582), oral anticoagulants (n=15 435), or antiplatelets (n=7726). Around one-fifth of people discontinued therapy within 90 days, with 50% discontinuing within the first year. Although many people achieved high adherence (proportion of days covered ≥80%) within the first year, these rates were higher when measured from first to last dispensing (40.5% and 53.2% for statins; 55.6% and 80.5% for antiplatelets, respectively). Persistence was low at 3 years (17.5% antiplatelets to 37.3% anticoagulants). Persistence and adherence increased with age, with minor differences by sex. Over one-third of people had cardiovascular multimedicine use (reaching 92% among antiplatelet users): they had higher persistence and adherence than people using medicines from only 1 cardiovascular group. Conclusions Persistence to cardiovascular medicines decreases substantially following initiation, but adherence remains high while people are using therapy. Cardiovascular multimedicine use is common, and people using multiple cardiovascular medicines have higher rates of persistence and adherence.

Opioid prescribing patterns among medical practitioners in New South Wales, Australia.

INTRODUCTION: Prescriber behaviour is important for understanding opioid use patterns. We described variations in practitioner-level opioid prescribing in New South Wales, Australia (2013-2018). METHODS: We quantified opioid prescribing patterns among medical practitioners using population-level dispensing claims data, and used partitioning around medoids to identify clusters of practitioners who prescribe opioids based on prescribing patterns and patient characteristics identified from linked dispensing claims, hospitalisations and mortality data. RESULTS: The number of opioid prescribers ranged from 20,179 in 2013 to 23,408 in 2018. The top 1% of practitioners prescribed 15% of all oral morphine equivalent (OME) milligrams dispensed annually, with a median of 1382 OME grams (interquartile range [IQR], 1234-1654) per practitioner; the bottom 50% prescribed 1% of OMEs dispensed, with a median of 0.9 OME grams (IQR 0.2-2.6). Based on 63.6% of practitioners with ≥10 patients filling opioid prescriptions in 2018, we identified four distinct practitioner clusters. The largest cluster prescribed multiple analgesic medicines for older patients (23.7% of practitioners) accounted for 76.7% of all OMEs dispensed and comprised 93.0% of the top 1% of practitioners by opioid volume dispensed. The cluster prescribing analgesics for younger patients with high rates of surgery (18.7% of practitioners) prescribed only 1.6% of OMEs. The remaining two clusters comprised 21.2% of prescribers and 20.9% of OMEs dispensed. DISCUSSION AND CONCLUSION: We observed substantial variation in opioid prescribing among practitioners, clustered around four general patterns. We did not assess appropriateness but some prescribing patterns are concerning. Our findings provide insights for targeted interventions to curb potentially harmful practices.

Psychotropic and other medicine use at time of death by suicide: a population-level analysis of linked dispensing and forensic toxicology data.

OBJECTIVES: To determine the numbers and types of medicines dispensed around the time of death to people who die by suicide; to compare the medicines recently dispensed and those recorded in post mortem toxicology reports. DESIGN, SETTING, PARTICIPANTS: Analysis of linked National Coronial Information System (NCIS) and Pharmaceutical Benefits Scheme (PBS) data from the Australian Suicide Prevention using Health Linked Data (ASHLi) study, a population-based case series study of closed coronial cases for deaths of people in Australia aged ten years or more during 1 July 2013 - 10 October 2019 deemed by coroners to be the result of intentional self-harm. MAIN OUTCOME MEASURES: Proportions of people to whom medicines were dispensed around the time of death, by medicine group, class, and specific medicine; comparison of medicines recently dispensed and those detected by post mortem toxicology. RESULTS: Toxicology reports were available for 13 541 of 14 206 people who died by suicide (95.3%; 10 246 men, 75.7%); poisoning with medicines contributed to 1163 deaths (8.6%). At least one PBS-subsidised medicine had been dispensed around the time of death to 7998 people (59.1%). For three medicine classes, the proportions of people in whom the medicines were detected post mortem and their death was deemed medicine-related were larger for those without records of recent dispensing than for people for whom they had been dispensed around the time of death: antidepressants (17.7% v 12.0%), anxiolytics (16.3% v 14.8%), and sedatives/hypnotics (24.3% v 16.5%). At least one recently dispensed medicine not detected post mortem was identified for 6208 people (45.8%). CONCLUSIONS: A considerable proportion of people who died by suicide were not taking psychotropic medicines recently dispensed to them, suggesting non-adherence to pharmacotherapy, and a smaller than expected proportion were using antidepressants. Conversely, medicines that had not recently been dispensed were detected post mortem in many people for whom poisoning with medicines was a contributing factor, suggesting medicine stockpiling.

The effects of the 4/20 cannabis holiday and adult-use cannabis legalization on medical cannabis sales and medical cannabis patient registration in Arizona.

BACKGROUND: This study examined whether the 4/20 cannabis holiday was associated with increases in medical cannabis sales from licensed dispensaries in Arizona from 2018-2021, and whether adult-use cannabis legalization (the vote in November 2020 and retail sales in January 2021) was associated with declines in medical cannabis sales and in the number of registered medical patients. METHODS: Data came from the Arizona Medical Marijuana Program monthly reports from January 2018-December 2021. The reports show daily sales from licensed medical cannabis dispensaries (i.e., the number of medical cannabis dispensary transactions and the amount of cannabis sold in pounds), which we averaged by week, and show the number of registered medical cannabis patients each month. Autoregressive integrated moving average models were used to test changes in these outcomes associated with the 4/20 cannabis holiday and with legalization of adult-use cannabis. RESULTS: During the week of the 4/20 cannabis holiday, medical cannabis dispensary transactions abruptly increased by an average of 2,319.4 transactions each day (95% CI: 1636.1, 3002.7), and the amount of medical cannabis sold increased by an average of 120.3 pounds each day (95% CI: 99.3-141.3). During the first week of adult-use cannabis sales in late January 2021, medical cannabis dispensary transactions abruptly decreased by an average of 5,073 transactions each day (95% CI: -5,929.5, -4216.7), and the amount of medical cannabis sold decreased by an average of 119.1 pounds each day (95% CI: -144.2, -94.0). Moreover, medical cannabis sales continued to gradually decline each week after the start of adult-use retail sales, with declines in sales preceding declines in registered patients. By December 2021, slightly over a year after the vote to legalize adult-use cannabis, the actual number of registered medical cannabis patients fell short of the forecasted number, had adult-use not been legalized, by 36.5%. Moreover, the number of medical dispensary transactions and the amount of medical cannabis sold fell short of expectations, had adult-use cannabis not been legalized, by 58% and 53%, respectively. CONCLUSIONS: Findings document the blurred boundary between medical and non-medical cannabis use and are consistent with the possibility that medical cannabis legalization contributes to increases in adult cannabis use and dependence.

Blood, dose recommendation reports and phone calls: Experiences of a therapeutic drug monitoring advisory service for vancomycin.

Dose-prediction software is recommended to enable area under the curve over 24 h (AUC24 )-guided dosing of the antibiotic vancomycin. However, uncertainty remains about how best to implement software in the clinic. We describe the activity, over 18 months, of a consultative therapeutic drug monitoring Advisory Service (the Service) for vancomycin that used dose-prediction software alongside clinical expertise, identifying factors that influence attainment of therapeutic targets. Of the 408 vancomycin dose reports provided for 182 courses of therapy, most (57%) recommended a dose change. The majority (82.8%, 193/233) of recommended dose adjustments were accepted by treating teams. A dose report was not published for 125 courses of therapy, with reasons including patient in intensive care unit or service error. An estimated 26.6 h of staff time was allocated to Service activities each month. Publication of a dose report facilitated attainment of therapeutic targets (P = .002). Software integration could improve Service outcomes, avoiding errors and reducing staff workload.

Potential drug-drug interactions due to concomitant medicine use among people living with HIV on antiretroviral therapy in Australia.

AIMS: We quantified concomitant medicine use and occurrence of potential drug-drug interactions in people living with HIV in Australia who are treated with antiretroviral therapy (ART). METHODS: In this cohort study using dispensing claims of a 10% random sample of Australians, we identified 2230 people dispensed ART between January 2018 and December 2019 (mean age 49.0 years, standard deviation 12.0 years, 88% male). We examined concomitant medicine use by identifying nontopical medicines dispensed within 90-days of any antiretroviral medicine dispensing during a 12-month follow-up period. For every antiretroviral and nonantiretroviral pair, we identified and classified possible drug-drug interactions using the University of Liverpool HIV drug interactions database. RESULTS: A total of 1728 (78%) people were dispensed at least 1 and 633 (28%) 5 or more unique medicines in addition to ART in a 12-month period; systemic anti-infectives and medicines acting on the nervous system were the most common (68% and 56%, respectively). Among comedicated people, 1637 (95%) had at least 1 medicine combination classified as weak interactions, 558 (32%) interactions requiring close monitoring/dose adjustment and 94 (5%) that should not be coadministered. Contraindication or interactions requiring close monitoring/dose adjustment were more common among people receiving protease inhibitors (50-73% across different antiretrovirals), non-nucleoside reverse transcriptase inhibitors (35-64%), people using single-tablet combinations containing elvitegravir (30-46%) and those using tenofovir disoproxil (26-30%). CONCLUSION: Concomitant medicine use is widespread among people living with HIV in Australia. Despite a relatively low prevalence of contraindicated medicines, almost a third received medicines that require close monitoring or dose adjustment.

Changes in antidepressant use in Australia: A nationwide analysis (2015-2021).

BACKGROUND: Depression and anxiety affect 4-14% of Australians every year; symptoms may have been exacerbated during the COVID-19 pandemic. We examined recent patterns of antidepressant use in Australia in the period 2015-2021, which includes the first year of the pandemic. METHODS: We used national dispensing claims for people aged ⩾10 years to investigate annual trends in prevalent and new antidepressant use (no antidepressants dispensed in the year prior). We conducted stratified analyses by sex, age group and antidepressant class. We report outcomes from 2015 to 2019 and used time series analysis to quantify changes during the first year of the COVID-19 pandemic (March 2020-February 2021). RESULTS: In 2019, the annual prevalence of antidepressant use was 170.4 per 1000 women and 101.8 per 1000 men, an increase of 7.0% and 9.2% from 2015, respectively. New antidepressant use also increased for both sexes (3.0% for women and 4.9% for men) and across most age groups, particularly among adolescents (aged 10-17 years; 46-57%). During the first year of the COVID-19 pandemic, we observed higher than expected prevalent use (+2.2%, 95% CI = [0.3%, 4.2%]) among females, corresponding to a predicted excess of 45,217 (95% CI = [5,819, 84,614]) females dispensed antidepressants. The largest increases during the first year of the pandemic occurred among female adolescents for both prevalent (+11.7%, 95% CI = [4.1%, 20.5%]) and new antidepressant use (+15.6%, 95% CI = [8.5%, 23.7%]). CONCLUSION: Antidepressant use continues to increase in Australia overall and especially among young people. We found a differential impact of the COVID-19 pandemic in treated depression and anxiety, greater among females than males, and greater among young females than other age groups, suggesting an increased mental health burden in populations already on a trajectory of increased use of antidepressants prior to the pandemic. Reasons for these differences require further investigation.

Assessing the impact of implementing multiple adherence measures to antiretroviral therapy from dispensing data: a short report.

Pharmacy dispensing data are useful for estimating adherence to therapy. Here, we implement multiple adherence measures to antiretroviral therapy (ART) and provide an online tool for visualising results. We conducted a cohort study for 2,042 people dispensed ART in Australia. We assessed adherence using the Proportion of Days Covered (PDC) within 360 days of follow-up as a continuous measure and dichotomised (PDC ≥80%). We defined a covered day as the 1) exposure to ≥3 antiretrovirals at the same time 2) exposure to any antiretroviral 3) lowest number of days covered per antiretroviral 4) average of days covered over all antiretrovirals 5) highest number of days covered per antiretroviral. For each method, we conducted sensitivity analyses. The median PDC ranged between 93.3%-98.3%. Between 67.0%-87.7% of individuals were classified as adherent, with higher values for measure 2 (85.5%-89.7%) and lower values for measure 3 (67.0%-70.9%). Censoring loss to follow-up had a higher impact on adherence estimates than considering a grace period. The variation in adherence estimates can be substantial, especially when dichotomising adherence. Researchers should consider operationalising multiple measures to estimate adherence bounds and identify a range of people at risk of non-adherence for targeted interventions.

The association between psychostimulant use in pregnancy and adverse maternal and neonatal outcomes: results from a distributed analysis in two similar jurisdictions.

BACKGROUND: Conflicting evidence suggests a possible association between use of prescribed psychostimulants during pregnancy and adverse perinatal outcomes. METHODS: We conducted population-based cohort studies including pregnancies conceived between April 2002 and March 2017 (Ontario, Canada; N = 554 272) and January 2003 to April 2011 [New South Wales (NSW), Australia; N = 139 229]. We evaluated the association between exposure to prescription amphetamine, methylphenidate, dextroamphetamine or lisdexamfetamine during pregnancy and pre-eclampsia, placental abruption, preterm birth, low birthweight, small for gestational age and neonatal intensive care unit admission. We used inverse probability of treatment weighting based on propensity scores to balance measured confounders between exposed and unexposed pregnancies. Additionally, we restricted the Ontario cohort to social security beneficiaries where supplementary confounder information was available. RESULTS: In Ontario and NSW respectively, 1360 (0.25%) and 146 (0.10%) pregnancies were exposed to psychostimulants. Crude analyses indicated associations between exposure and nearly all outcomes [OR range 1.15-2.16 (Ontario); 0.97-2.20 (NSW)]. Nearly all associations were attenuated after weighting. Pre-eclampsia was the exception: odds remained elevated in the weighted analysis of the Ontario cohort (OR 2.02, 95% CI 1.42-2.88), although some attenuation occurred in NSW (weighted OR 1.50, 95% CI 0.77-2.94) and upon restriction to social security beneficiaries (weighted OR 1.24, 95% CI 0.64-2.40), and confidence intervals were wide. CONCLUSIONS: We observed higher rates of outcomes among exposed pregnancies, but the attenuation of associations after adjustment and likelihood of residual confounding suggests psychostimulant exposure is not a major causal factor for most measured outcomes. Our findings for pre-eclampsia were inconclusive; exposed pregnancies may benefit from closer monitoring.

A nationwide study of multimedicine use in people treated with cardiovascular medicines in Australia.

STUDY OBJECTIVE: Multimorbidity and multimedicine use are common in people with cardiovascular disease and can lead to harms, such as prescribing errors and drug interactions. We quantified multimedicine use in people treated with cardiovascular medicines in a national sample of Australians. DESIGN: Cross-sectional study. DATA SOURCE: Pharmaceutical dispensing claims for a 10% random sample of Australians. PATIENTS: Australian adults dispensed any cardiovascular medicine between June and August 2019. INTERVENTION: None. MEASUREMENTS: We quantified the number and type of cardiovascular and non-cardiovascular medicines dispensed during the study period, and the number of unique prescribers, by age and sex. MAIN RESULTS: We identified 493,081 people dispensed any cardiovascular medicine (median age = 67 years, 50.2% women). The population prevalence of cardiovascular medicine dispensing increased from 1.7% (n = 10,503) in people 18-34 years to 80.1% (n = 99,271) in people 75-84 years. Cardiovascular medicine dispensing varied by sex; women 18-34 years were more likely to be dispensed any cardiovascular medicine than men (male:female prevalence ratio [PR] = 0.84, 95% confidence interval [CI] = 0.81-0.87), whereas the prevalence of cardiovascular medicine dispensing was higher in men 35-44 years (PR = 1.27, 95% CI 1.24-1.30) and 45-54 years (PR = 1.24, 95% CI 1.22-1.26) and was similar between sexes in people ≥65 years. Overall, both women and men were dispensed a median of 2.0 (interquartile range [IQR] = 1.0-3.0) cardiovascular medicines. Two-thirds of people ≥65 years (73.5%; n = 208,524) were dispensed ≥2 cardiovascular medicines, with 16.6% (n = 6736) of people ≥85 years dispensed five or more. Women and men were dispensed a median of 2.0 (IQR = 1.0-5.0) and 2.0 (IQR = 0.0-4.0) non-cardiovascular medicines, respectively, to treat comorbid conditions, commonly gastroesophageal reflux disease medicines (32.2% of women and 26.6% of men), antibiotics (28.7% of women and 22.4% of men), and antidepressants (26.3% of women and 15.9% of men). One quarter of both sexes had multiple prescribers for their cardiovascular medicines alone, whereas 54.5% (n = 134,939) of women and 49.9% (n = 122,706) of men had multiple prescribers for all medicines. CONCLUSION: Multimedicine use is common in people treated with cardiovascular medicines and presents a risk for inappropriate prescribing. Understanding the comorbid conditions commonly treated concurrently with cardiovascular disease can help improve co-prescribing guidelines and develop a person-centered approach to multimorbidity treatment.