Innovations in pharmacovigilance studies of medicines in older people

Pharmacovigilance is defined by the World Health Organization as "the science and activities relating to the detection, assessment, understanding and prevention of adverse effects or any other medicine/vaccine related problem". Pharmacovigilance studies are critical for detecting and assessing adverse events of medicines that may not have been observed in clinical trials. This activity is especially important in older people who are often excluded from clinical trials as they have multiple chronic conditions and use multiple medicines for longer durations than the clinical trials. In this narrative review we describe innovative methods in pharmacovigilance studies of medicines in older people that leverage the increasing availability of digital health technologies, electronic health records and real-world health data to identify and quantify medication related harms in older people.

Prevalence and Preventability of Adverse Medicine Events in a Sample of Australian Aged-Care Residents: A Secondary Analysis of Data from the ReMInDAR Trial

BACKGROUND

Aged care residents are vulnerable to the harmful effects of medicines; however, data on the prevalence and preventability of adverse medicine events in aged care residents are scarce.

AIM

To determine the prevalence and preventability of adverse medicine events in Australian aged care residents.

METHODS

A secondary analysis of data from the Reducing Medicine-Induced Deterioration and Adverse Reactions (ReMInDAR) trial was conducted. Potential adverse medicine events were identified and independently screened by two research pharmacists to produce a short-list of potential adverse medicine events. An expert clinical panel reviewed each potential adverse medicine to determine the likelihood that the event was medicine related (based on the Naranjo Probability Scale criteria). The clinical panel assessed preventability of medicine-related events using Schumock-Thornton criteria.

RESULTS

There were 583 adverse events due to medicines, involving 154 residents (62% of the 248 study participants). There was a median of three medication-related adverse events (interquartile range [IQR] 1-5) per resident over the 12-month follow-up period. The most common medication-related adverse events were falls (56%), bleeding (18%) and bruising (9%). There were 482 (83%) medication-related adverse events that were preventable, most commonly falls (66% of preventable adverse medicine events), bleeding (12%) and dizziness (8%). Of the 248 residents, 133 (54% of the cohort) had at least one preventable adverse medicine event, with a median of 2 (IQR 1-4) preventable adverse medicine events per resident.

CONCLUSION

In total, 62% of aged care residents in our study had an adverse medicine event and 54% had a preventable adverse medicine event in a 12-month period.

Using wrist-worn accelerometers to identify the impact of medicines with anticholinergic or sedative properties on sedentary time: A 12-month prospective analysis

INTRODUCTION

Studies have shown that use of medicines with sedative or anticholinergic properties is associated with a decline in physical function; however, the effects have not been quantified, and it is not known how and which specific physical movements are affected. This prospective study quantified the impact of a change in sedative or anticholinergic load over time on 24-hour activity composition.

METHODS

This study used data collected from a randomised trial assessing an ongoing pharmacist service in residential aged care. The 24-hour activity composition of sleep, sedentary behaviour, light-intensity physical activity, and moderate to vigorous physical activity was derived from 24-hour accelerometry bands. Mixed effect linear models were used to regress the multivariate outcome of 24-hour activity composition on medication load at baseline and at 12 months. A fixed effect interaction between trial stage and medication load was included to test for differing sedative or anticholinergic load effects at the two trial stages.

RESULTS

Data for 183 and 85 participants were available at baseline and 12 months respectively. There was a statistically significant interaction between medication load and time point on the multivariate outcome of 24-hour activity composition (sedative F = 7.2, p < 0.001 and anticholinergic F = 3.2, p = 0.02). A sedative load increase from 2 to 4 over the 12-month period was associated with an average increase in daily sedentary behaviour by an estimated 24 min.

CONCLUSION

As sedative or anticholinergic load increased, there was an increase in sedentary time. Our findings suggest wearable accelerometry bands are a possible tool for monitoring the effects on physical function of sedative and anticholinergic medicines.

TRIAL REGISTRATION

The ReMInDAR trial was registered on the Australian and New Zealand Trials Registry ACTRN12618000766213.

Frailty trajectory over one year among residential aged care (nursing home) residents

Objectives

Large population-based studies examining frailty trajectory found a linear increase in frailty over time. The pattern in which frailty changes over time for an individual person is less well-described. We examined the frailty trajectory of older adults living in aged-care in Australia.

Materials and methods

This secondary study used data from a randomised controlled trial involving 39 aged-care facilities in Australia. The trial intervention was an on-going pharmacist-led intervention occurring every 8 weeks over 12 months aimed at preventing medicine-induced deterioration and adverse reactions. Frailty was assessed using the Frailty Index. Participants were categorised as non-frail, pre-frail and frail. Individual frailty trajectory over 12 months was visualised using the alluvial plot. Case notes were examined to explore reasons for any rapid transitions in frailty status.

Results

A total of 248 participants was included. At baseline, 40.3% were non-frail and 59.7% were pre-frail. The proportion of participants who were non-frail and pre-frail decreased over time; 15.7% were frail at 6 months and 23.4% were frail at 12 months. Overall, twenty different combinations of frailty transitions were identified over 12 months. Retrospective analysis of case notes suggest that death or transition from non-frail to frail was often preceded by hospitalisation, falls, medication change or clinically significant deterioration in grip strength or cognition.

Conclusion

The degree of frailty increased over time, but there were variations in the individual trajectories. Regular monitoring of events that precede changes in frailty status is needed to identify strategies to prevent further deterioration in residents’ conditions.

A comparison of survival models for prediction of eight-year revision risk following total knee and hip arthroplasty

Background

There is increasing interest in the development and use of clinical prediction models, but a lack of evidence-supported guidance on the merits of different modelling approaches. This is especially true for time-to-event outcomes, where limited studies have compared the vast number of modelling approaches available. This study compares prediction accuracy and variable importance measures for four modelling approaches in prediction of time-to-revision surgery following total knee arthroplasty (TKA) and total hip arthroplasty (THA).

Methods

The study included 321,945 TKA and 151,113 THA procedures performed between 1 January 2003 and 31 December 2017. Accuracy of the Cox model, Weibull parametric model, flexible parametric model, and random survival forest were compared, with patient age, sex, comorbidities, and prosthesis characteristics considered as predictors. Prediction accuracy was assessed using the Index of Prediction Accuracy (IPA), c-index, and smoothed calibration curves. Variable importance rankings from the Cox model and random survival forest were also compared.

Results

Overall, the Cox and flexible parametric survival models performed best for prediction of both TKA (integrated IPA 0.056 (95% CI [0.054, 0.057]) compared to 0.054 (95% CI [0.053, 0.056]) for the Weibull parametric model), and THA revision. (0.029 95% CI [0.027, 0.030] compared to 0.027 (95% CI [0.025, 0.028]) for the random survival forest). The c-index showed broadly similar discrimination between all modelling approaches. Models were generally well calibrated, but random survival forest underfitted the predicted risk of TKA revision compared to regression approaches. The most important predictors of revision were similar in the Cox model and random survival forest for TKA (age, opioid use, and patella resurfacing) and THA (femoral cement, depression, and opioid use).

Conclusion

The Cox and flexible parametric models had superior overall performance, although all approaches performed similarly. Notably, this study showed no benefit of a tuned random survival forest over regression models in this setting.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12874-022-01644-3.

The Extent of Medication-Related Hospital Admissions in Australia: A Review from 1988 to 2021

Introduction

Medication-related problems often lead to patient harm. This paper aims to review the Australian literature to determine the overall incidence, severity and preventability of medication-related hospital admissions, as well as providing a national estimate on their extent and cost.

Methods

The first part of the paper includes a literature search to identify studies that provided estimates of medication-related problems that caused hospital admissions. Incidence of medication-related hospital admissions, type of medication-related problem contributing to admission (e.g. adverse medicine reaction) and method used to estimate incidence (e.g. chart review) were extracted. Data on severity and preventability of the admissions were extracted where available. The second part of the paper involves use of methodological triangulation to estimate the extent and cost of medication-related hospital admission. Median estimates used to assess medication-related hospital admissions and the 2019–2020 national hospital admissions data were used to calculate the national estimate on the extent of medication-related hospital admission. Costs were also estimated.

Results

Seventeen studies provided estimates on the extent of medication-related hospital admissions as assessed using medication chart review. The median incidence of 2.5% (interquartile range [IQR] 0.6%) as a proportion of all hospital admissions suggests 275,000 hospital admissions annually in Australia are medication related. The median incidence of 9% (IQR 3.9%) of emergency admissions suggests that 270,000 admissions annually are medication related. Eight studies provided estimates of the extent of medication-related hospital admissions identified from administrative health data; the median incidence of 1.7% with an under-reporting rate of 82% suggests 280,000 hospital admissions annually are medication related. Triangulation of results suggests that at least 250,000 hospital admissions annually in Australia are medication related, with an estimated cost of 1.4 billion Australian dollars (AUD$). Five studies assessed severity, and nine studies assessed preventability. Preventability estimates suggest two-thirds of medication-related hospital admissions are potentially preventable.

Conclusions

We estimated that 250,000 hospital admissions in Australia are medication related, with an annual cost of AUD$1.4 billion to the healthcare system. Two-thirds of medication-related hospital admissions are potentially preventable.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40264-021-01144-1.

Medication-related hospital admissions in aged care residents

OBJECTIVE

To determine the prevalence of medication-related hospitalisations preceded by potentially suboptimal processes of care in aged care residents.

METHOD

We conducted a retrospective analysis of administrative claims data from the Australian Government Department of Veterans' Affairs (DVA). We identified all hospital admissions for aged care residents between 1 July 2014 and 30 June 2019. The proportion of hospital admissions preceded by potentially suboptimal medication-related processes of care was determined.

RESULTS

A total of 18 874 hospitalisations were included, and 46% were preceded by potentially suboptimal medication-related care. One-quarter of fracture admissions occurred in residents at risk of fracture who were not using a medicine to prevent fracture, and 87% occurred in residents using falls-risk medicines. Thirty per cent of heart failure admissions occurred in patients who were not using an angiotensin-converting enzyme inhibitor or angiotensin receptor blocker.

CONCLUSION

Nearly half of hospital admissions were preceded by potentially suboptimal medication-related processes of care. Interventions to improve use of medicines for aged care residents in these areas are warranted.

The effects of anticholinergic medications on cognition in children: a systematic review and meta-analysis

Cognitive side effects of anticholinergic medications in older adults are well documented. Whether these poor cognitive outcomes are observed in children has not been systematically investigated. We aimed to conduct a systematic review and meta-analysis on the associations between anticholinergic medication use and cognitive performance in children. Systematic review was conducted using Medline, PsychInfo, and Embase, identifying studies testing cognitive performance relative to the presence versus absence of anticholinergic medication(s) in children. We assessed effects overall, as well as relative to drug class, potency (low and high), cognitive domain, and duration of administration. The systematic search identified 46 articles suitable for meta-analysis. For the most part, random effects meta-analyses did not identify statistically significant associations between anticholinergic exposure and cognitive performance in children; the one exception was a small effect of anticholinergic anti-depressants being associated with better cognitive function (Hedges' g = 0.24, 95% CI 0.06-0.42, p = 0.01). Anticholinergic medications do not appear to be associated with poor cognitive outcomes in children, as they do in older adults. The discrepancy in findings with older adults may be due to shorter durations of exposure in children, differences in study design (predominantly experimental studies in children rather than predominantly epidemiological in older adults), biological ageing (e.g. blood brain barrier integrity), along with less residual confounding due to minimal polypharmacy and comorbidity in children.

Impact of a patient-specific national programme aimed at increasing the use of emollient moisturisers to reduce the risk of skin tears: a longitudinal cohort study

OBJECTIVES

To evaluate the impact of a patient-specific national programme targeting older Australians and health professionals that aimed to increase use of emollient moisturisers to reduce to the risk of skin tears.

DESIGN

A prospective cohort intervention.

PARTICIPANTS

The intervention targeted 52 778 Australian Government's Department of Veterans' Affairs patients aged over 64 years who had risk factors for wound development, and their general practitioners (GPs) (n=14 178).

OUTCOME MEASURES

An interrupted time series model compared the rate of dispensing of emollients in the targeted cohort before and up to 23 months after the intervention. Commitment questions were included in self-report forms.

RESULTS

In the first month after the intervention, the rate of claims increased 6.3-fold (95% CI: 5.2 to 7.6, p<0.001) to 10 emollient dispensings per 1000 patients in the first month after the intervention. Overall, the intervention resulted in 10 905 additional patient-months of treatment. The increased rate of dispensing among patients who committed to talking to their GP about using an emollient was six times higher (rate ratio: 6.2, 95% CI: 4.4 to 8.7) than comparison groups.

CONCLUSIONS

The intervention had a sustained effect over 23 months. Veterans who responded positively to commitment questions had higher uptake of emollients than those who did not.

Potentially inappropriate medication use and related hospital admissions in aged care residents: The impact of dementia

AIMS

To determine the prevalence of potentially inappropriate medication (PIM) use at hospital admission and discharge, and the contribution to hospital admission among residential aged care facility residents with and without dementia.

METHODS

We conducted a secondary analysis using data from a multihospital prospective cohort study involving consecutively admitted older adults, aged 75 years or older, who were taking 5 or more medications prior to hospital admission and discharged to a residential aged care facility in South Australia. PIM use was identified using the 2015 Screening Tool for Older Persons' Prescription and 2019 Beers criteria. An expert panel of clinicians with geriatric medicine expertise evaluated the contribution of PIM to hospital admission.

RESULTS

In total, 181 participants were included, the median age was 87.5 years and 54.7% were female. Ninety-one (50.3%) had a diagnosis of dementia. Participants with dementia had fewer PIMs, according to at least 1 of the 2 screening criteria, than those without dementia, at admission (dementia: 76 [83.5%] vs no dementia: 84 [93.3%], P = .04) and discharge (78 [85.7%] vs 83 [92.2%], P = .16). PIM use was causal or contributory to the admission in 28.1% of study participants (n = 45) who were taking at least 1 PIM at admission.

CONCLUSIONS

Over 80% of acutely admitted older adults took PIMs at hospital admission and discharge and for over a quarter of these people the admissions were attributable to PIM use. Hospitalisation presents an opportunity for comprehensive medication reviews, and targeted interventions that enhance such a process could reduce PIM use and related harm.

Comorbidities in an Australian sample of chronic and new opioid users

INTRODUCTION AND AIMS

Mental health disorders and substance abuse are risk factors that both precede and follow chronic opioid use. We predicted that incident opioid users would have lower rates of mental health comorbidities than chronic opioid users, but that incident chronic opioid users would have lower rates of mental health comorbidities than prevalent chronic users.

DESIGN AND METHODS

We used administrative health claims data to evaluate differences in lifetime mental health and substance abuse comorbidity profiles of people who were prevalent and incident chronic opioid users, as well as those who used opioids acutely. Results were stratified by age.

RESULTS

Over 5,188 people were prevalent chronic opioid users at study entry. Of the 10,079 people who initiated opioids, 10.2 per-cent had a subsequent chronic episode (incident chronic) and the remainder stopped within 90 days (incident acute). In prevalent chronic users compared to incident chronic users, rates of depression and anxiety were higher across all age groups (odds ratio (OR) across age groups range from = 1.60, 95 percent confidence interval (CI) = 1.35,1.89, to OR = 6.66, 95 percent CI = 3.02, 14.69) and prevalence of alcohol abuse was higher in those aged 55 to 74 years (OR = 5.11, 95 percent CI = 1.83, 14.24, p = 0.002). Acute users were less likely than incident chronic users to have depression and anxiety in those aged over 74 years (depression OR = 0.82, 95 per-cent CI = 0.70, 0.95; anxiety OR = 0.82, 95% CI 0.70, 0.98).

CONCLUSIONS

Mental health morbidities commonly associated with chronic opioid use increase in prevalence as chronic use continues.

Reducing medicine-induced deterioration and adverse reactions (ReMInDAR) trial: study protocol for a randomised controlled trial in residential aged-care facilities assessing frailty as the primary outcome

INTRODUCTION

Many medicines have adverse effects which are difficult to detect and frequently go unrecognised. Pharmacist monitoring of changes in signs and symptoms of these adverse effects, which we describe as medicine-induced deterioration, may reduce the risk of developing frailty. The aim of this trial is to determine the effectiveness of a 12-month pharmacist service compared with usual care in reducing medicine-induced deterioration, frailty and adverse reactions in older people living in aged-care facilities in Australia.

METHODS AND ANALYSIS

The reducing medicine-induced deterioration and adverse reactions trial is a multicentre, open-label randomised controlled trial. Participants will be recruited from 39 facilities in South Australia and Tasmania. Residents will be included if they are using four or more medicines at the time of recruitment, or taking more than one medicine with anticholinergic or sedative properties. The intervention group will receive a pharmacist assessment which occurs every 8 weeks. The pharmacists will liaise with the participants' general practitioners when medicine-induced deterioration is evident or adverse events are considered serious. The primary outcome is a reduction in medicine-induced deterioration from baseline to 6 and 12 months, as measured by change in frailty index. The secondary outcomes are changes in cognition scores, 24-hour movement behaviour, grip strength, weight, percentage robust, pre-frail and frail classification, rate of adverse medicine events, health-related quality of life and health resource use. The statistical analysis will use mixed-models adjusted for baseline to account for repeated outcome measures. A health economic evaluation will be conducted following trial completion using data collected during the trial.

ETHICS AND DISSEMINATION

Ethics approvals have been obtained from the Human Research Ethics Committee of University of South Australia (ID:0000036440) and University of Tasmania (ID:H0017022). A copy of the final report will be provided to the Australian Government Department of Health.

TRIAL REGISTRATION NUMBER

Australian and New Zealand Trials Registry ACTRN12618000766213.

Risk of chronic opioid use in older persons with pre-existing anxiety

OBJECTIVE

Work that has shown a relationship between anxiety and chronic opioid use has not focused on older people specifically, despite the additional risks in older populations. This study aimed to understand whether anxiety prior to opioid initiation increased the likelihood of chronic opioid use over time in persons aged 60 years or older.

DESIGN

Administrative claims data were used to calculate time between initiation of opioids and a first chronic episode of opioid use. Patients were classified as having a history of anxiety if they were dispensed medicines in the anxiolytics class or had a hospitalization event for anxiety prior to treatment with an opioid. Proportional hazards models were used to compare the likelihood of experiencing a chronic episode of opioid use between those with and without a history of anxiety.

RESULTS

The cohort was 15,000 persons, of which, 5,076 (34 percent) had history of anxiety. Those with anxiety prior to their first opioid dispensing were 30 percent more likely to have an episode of chronic use after adjustment for age, gender, number of comorbidities, and prior surgery (HR = 1.30, 95% CI = 1.16-1.47). The risk of a chronic episode in patients who had surgery prior to initiation of an opioid was 60 percent greater in those with anxiety compared to no anxiety (HR = 1.60, 95% CI = 1.21-2.11) and 24 percent greater in those with anxiety but no prior surgery (HR = 1.24, 95% CI = 1.08-1.42).

CONCLUSIONS

A significant proportion of older people will have a chronic episode of opioid use. This risk is increased where a history of anxiety is present.

Adaptation of potentially preventable medication-related hospitalisation indicators for Indigenous populations in Australia using a modified Delphi technique

OBJECTIVES

One of the outcomes of a medication review service is to identify and manage medication-related problems (MRPs). The most serious MRPs may result in hospitalisation, which could be preventable if appropriate processes of care were adopted. The aim of this study was to update and adapt a previously published set of clinical indicators for use in assessing the effectiveness of a medication review service tailored to meet the needs of Indigenous people, who experience some of the worst health outcomes of all Australians.

DESIGN

A modified Delphi technique was used to: (i) identify additional indicators for consideration, (ii) assess whether the original indicators were relevant in the context of Indigenous health and (iii) reach consensus on a final set of indicators. Three rounds of rating were used via an anonymous online survey, with 70% agreement required for indicator inclusion.

SETTING

The indicators were designed for use in Indigenous primary care in Australia.

PARTICIPANTS

Thirteen panellists participated including medical specialists, general practice doctors, pharmacists and epidemiologists experienced in working with Indigenous patients.

RESULTS

Panellists rated 101 indicators (45 from the original set and 57 newly identified). Of these, 41 were accepted unchanged, seven were rejected and the remainder were either modified before acceptance or merged with other indicators. A final set of 81 indicators was agreed. Conclusions This study provides a set of clinical indicators to be used as a primary outcome measure for medication review services for Indigenous people in Australia and as a prompt for pharmacists and doctors conducting medication reviews.

TRIAL REGISTRATION NUMBER

The trial registration for the Indigenous Medication Review Service feasibility study is ACTRN12618000188235.

Potentially inappropriate prescribing in people with dementia: An Australian population-based study

OBJECTIVE

To investigate the prevalence of potentially inappropriate prescribing (PIP) using the Screening Tool of Older Person's Prescriptions (STOPP) criteria in people with dementia compared with people without dementia.

METHODS

A retrospective cohort study was conducted using the Pharmaceutical Benefits Scheme 10% sample of pharmacy claims. People with dementia were defined as those dispensed a medicine for dementia (cholinesterase inhibitors, memantine, or risperidone for behavioural and psychological symptoms of dementia) between 1 January 2005 and 31 December 2015, aged 65 years or older at 1 January 2016 and alive at the end of 2016. An age- and gender-matched comparison cohort of people not dispensed medicines for dementia was identified. PIP prevalence was determined between 1 January 2016 and 31 December 2016.

RESULTS

In total, 8280 people dispensed medicines for dementia and 41 400 comparisons not dispensed medicines for dementia were included: 63% were female and the median age was 82 years. PIP prevalence was 79% among people with dementia compared with 70% among the comparison group (P < .0001). Use of anticholinergics, long-term use of high-dose proton pump inhibitors, and use of benzodiazepines were the most common instances of PIP in people with dementia. After adjustments for age, gender, comorbidity, and number of prescribers, people with dementia were more likely to be exposed to PIP than comparisons (adjusted OR 1.44, 95% CI, 1.35-1.53, P < .0001).

CONCLUSIONS

PIP was more common in people dispensed medicines for dementia than comparisons. These results highlight the need for effective interventions to optimize prescribing in people with dementia.

Analysis of anticholinergic and sedative medicine effects on physical function, cognitive function, appetite and frailty: a cross-sectional study in Australia

OBJECTIVE

To test the association between use of medicines with anticholinergic or sedative properties and physical function, cognitive function, appetite and frailty.

DESIGN, SETTING AND PARTICIPANTS

This cross-sectional study analysed baseline data collected as part of the Australian Longitudinal Study of Ageing, a population-based cohort of 2087 participants aged 65 years or over living in South Australia.

MAIN OUTCOME MEASURES

Physical function was measured at baseline using measures including hand grip strength, walking speed, chair stands, activities of daily living and instrumental activities of daily living (IADL). Cognitive function was measured using Mini-Mental State Examination. Appetite was measured using Center for Epidemiologic Studies Depression question 2. Frailty was measured using frailty index. The association between use of anticholinergics or sedatives and physical or cognitive function, appetite, or frailty was assessed using analysis of covariance and ordinal or binary logistic regression.

RESULTS

Almost half of the population were using anticholinergics or sedatives (n=954, 45.7%). Use of anticholinergics was significantly associated with poorer grip strength, slower walking speed, poorer IADL and poorer appetite. Use of sedatives was significantly associated with poorer grip strength, slower walking speed and poorer IADL. We found no significant association between medicine use and cognitive function. Users of anticholinergics or sedatives were significantly more likely to be frail compared with non-users.

CONCLUSION

Use of medicines with anticholinergic or sedative properties is significantly associated with poorer physical function, poorer appetite and increased frailty. Early identification of signs and symptoms of deterioration associated with medicine use is particularly important in older people so that worsening frailty and subsequent adverse events are prevented.

Reduction in Use of Risperidone for Dementia in Australia Following Changed Guidelines

Background: Risperidone is the only antipsychotic approved in Australia for the management of the behavioural and psychological symptoms of dementia (BPSD). In June 2015, the Australian Government Therapeutic Goods Administration (TGA) amended the indication to restrict use in BPSD to patients with Alzheimer's dementia for a maximum twelve-week duration. We aimed to determine whether the rate and duration of risperidone use for BPSD decreased following the regulatory changes. Methods: we conducted a study using the Australian Government Department of Veterans' Affairs administrative claims data and Pharmaceutical Benefits Scheme (PBS) 10% sample data. We included people aged 65 years or older and compared the rate and duration of risperidone use before and after the TGA labelling changes. Results: There was a sustained decrease in the trend of risperidone use for BPSD following the TGA labelling changes, with a monthly decrease of 1.7% in the aged care population, 0.5% in the community living population and 1.5% in the general older Australian population. Overall, in the 24 months post the TGA changes the reduction in the rate of use of risperidone ranged from 20% to 28% lower than compared to what the rate would have been without the TGA changes. The median duration of use of risperidone in aged-care residents decreased from 338 days in the year prior to the TGA labelling changes, to 240 days per person in the year after the changes. Conclusion: The TGA labelling changes were associated with a significant reduction in the rate of use of risperidone for BPSD in veterans living in both the aged care and community settings, and in the general older Australian population. The labelling changes were also associated with a reduced duration of risperidone use in aged care residents, although for most people the duration of use still exceeded the recommended 12-week maximum duration.

Initiation and continuation of antipsychotic medicines in older people following non-psychiatric hospital admission

Background Internationally, antipsychotics are frequently initiated during hospital admission for older patients and use often continues post-discharge without indication. We located no Australian studies on this topic. Objective to identify the hospital admissions (excluding psychosis) associated with antipsychotic initiation and continuation in older Australians. Setting Australian Government Department of Veterans' Affairs. Method Retrospective analysis of administrative claims data for people admitted to hospital from 1 January 2014 to 31 December 2014, aged ≥ 65 years, who were antipsychotic naïve. Main outcome measure number of admissions associated with antipsychotic initiation, and the major diagnosis groups for these admissions. Where antipsychotics were initiated, we determined the time to cessation of antipsychotics after discharge. Results There were 142,009 hospital admissions for 66,415 people with a median age of 86 years. 921 (0.65%) admissions were associated with antipsychotic initiation, most commonly where the primary diagnoses were for mental and behavioural disorders excluding psychosis (17.8%) and injuries (16%). Fourteen percent of antipsychotic initiations were for primary diagnoses of delirium or dementia. When secondary diagnoses were considered, 55% of antipsychotic initiations were associated with delirium, dementia or both. The median duration of use among people who used antipsychotics was 132 days, and 40% continued use until death or one year follow-up. Conclusion Initiation of antipsychotics during hospital admissions was not frequent in this Australian population. Amongst those who did initiate antipsychotics, for almost half no diagnosis corresponding with an approved indication for use was recorded and long-term use of up to one year was common.

Prevalence and Duration of Use of Medicines Recommended for Short-Term Use in Aged Care Facility Residents

Background: Multiple studies have assessed the appropriateness of the use of medicines for nursing home residents; however, few have included duration of use in their assessment. The aim of this study was to assess the level and duration of use of medications recommended for short-term use in residents of aged care facilities in Australia. Methods: Australian Government Department of Veterans’ Affairs (DVA) administrative claims data were used for this study. Veterans eligible for all health services subsidised by DVA were followed for one year from 1 July 2015 to 30 June 2016. The number of days covered for each medicine was calculated by multiplying the number of prescriptions dispensed during the year by the pack duration for the medicine. The pack duration was calculated by dividing the quantity supplied at each dispensing by the usual number of doses per day in older people according to Australian prescribing guidelines. The proportion of patients using each medicine and the number of days covered during the study period were determined. Results: 14, 237 residents met the inclusion criteria. One in five participants were dispensed antipsychotics, and the median duration of use was 180 days in the one-year period. More than one-third were dispensed a benzodiazepine, and the median duration of use was 240 days in the year. Half were dispensed an opioid analgesic with a median duration of use of 225 days in the year. Fifty-two percent were dispensed proton pump inhibitors with a median duration of use of 360 days in the year. A quarter received an antibiotic recommended for the management of urinary tract infection, with a median duration of use of 14 days in the year. Conclusion: Long-term use of antipsychotics, benzodiazepines, opioid analgesics and proton pump inhibitors is common in aged care residents. Ensuring appropriate duration of use for these medicines is necessary to reduce risk of harm.

Potentially inappropriate prescribing before and after initiation of medicines for dementia: An Australian population-based study

AIM

To evaluate the prevalence of potentially inappropriate prescribing (PIP), as defined by the internationally validated Screening Tool of Older Person's Prescriptions (STOPP) criteria, in 12 months before and after initiation of medicines for dementia.

METHODS

A retrospective cohort study was carried out involving people with their first claim for dispensing of medicines for dementia (cholinesterase inhibitor or memantine) between 1 January 2015 and 31 December 2015, aged ≥65 years at 1 January 2016 and alive at the end of 2016. The index date was defined as the date of first supply of medicines for dementia. PIP was identified using the Screening Tool of Older Person's Prescriptions criteria, and PIP prevalence was compared in the 12 months pre- and post-index date. The McNemar's test was used to test differences in the prevalence of PIP between the two time periods.

RESULTS

The cohort included 1176 patients: 60% were women and the median age was 80 years. The overall PIP prevalence was 85% in the 12 months pre-initiation of medicines for dementia compared with 89% in the 12 months post-initiation (P < 0.0001). The median number of Screening Tool of Older Person's Prescriptions criteria was two (interquartile range 1-4) in the 12 months pre-initiation of medicines for dementia, increasing to three (range 2-4) in the 12 months post-initiation.

CONCLUSIONS

PIP was common in people dispensed medicines for dementia, with a significant increase in prevalence post-initiation of medicines for dementia compared with pre-initiation. These results highlight the need for targeted interventions to minimize inappropriate use of medicines in people with dementia. Geriatr Gerontol Int 2019; 19: 654-659.

Comparative effectiveness and safety of low-strength and high-strength direct oral anticoagulants compared with warfarin: a sequential cohort study

OBJECTIVES

The aim of this study was to compare effectiveness and safety of low-strength and high-strength direct oral anticoagulants (DOACs) with warfarin in the Australian Veteran population.

DESIGN

Sequential cohort study using inverse probability of treatment weighting (IPTW) and propensity score matching. Initiators of high-strength (apixaban 5 mg, dabigatran 150 mg, rivaroxaban 20 mg) and low-strength DOACS (apixaban 2.5 mg, dabigatran 110 mg, rivaroxaban 15 mg) were compared with warfarin initiators.

SETTING

Australian Government Department of Veterans' Affairs claims database.

PARTICIPANTS

4836 patients who initiated oral anticoagulants (45.8%, 26.0% and 28.2% on low-strength, high-strength DOACs and warfarin, respectively) between August 2013 and March 2015. Mean age was 85, 75 and 83 years for low-strength, high-strength DOACs and warfarin initiators, respectively.

MAIN OUTCOME MEASURES

One-year risk of hospitalisation for ischaemic stroke, any bleeding event or haemorrhagic stroke. Secondary outcomes were 1-year risk of hospitalisation for myocardial infarction and death.

RESULTS

Using the IPTW method, no difference in risk of ischaemic stroke or bleeding was found with low-strength DOACs compared with warfarin. As a class, no increased risk of myocardial infarction was found for low-strength DOACs, however, risk was elevated for apixaban (HR 2.25, 95% CI 1.23 to 4.13). For high-strength DOACs, no difference was found for ischaemic stroke compared with warfarin, however, there was a significant reduction in risk of bleeding events (HR 0.63, 95% CI 0.44 to 0.89) and death (HR 0.40, 95% CI 0.28 to 0.58). Propensity score matching showed no difference in risk of ischaemic stroke or bleeding.

CONCLUSION

We found that in the practice setting both DOAC formulations were similar to warfarin with regard to effectiveness and had no increased risk of bleeding.

Reducing hypnotic use in insomnia management among Australian veterans: results from repeated national interventions

BACKGROUND

The Australian Government Department of Veterans' Affairs (DVA) Veterans' Medicines Advice and Therapeutics Education Services (Veterans' MATES) programme conducted two intervention (March 2009, follow-up intervention June 2012) both of which aimed to reduce hypnotic use among Australian veterans. We evaluated the effectiveness of the interventions, and estimated the associated health consequences.

METHODS

Both interventions targeted veterans who had been dispensed hypnotics prior to the intervention. Patient-specific prescriber feedback containing patient details and the volume of hypnotics dispensed, along with tailored educational information, was mailed to general practitioners. Veterans, pharmacists and directors of care in residential aged care facilities were mailed tailored educational information. Interrupted time-series and segmented regression modelling were used to determine the effect of the two interventions on the rate of hypnotics dispensing. The cumulative patient-months of hypnotic treatment avoided as a result of the interventions was calculated. We estimated improvements in health consequences of as a result of hypnotic treatment avoided based on the results of cohort studies in the same population identifying the association between hypnotic and sedative use on the outcomes of falls, and confusion.

RESULTS

After the first Veterans' MATES intervention in March 2009, hypnotic use declined by 0.2% each month, when compared to the baseline level (p = 0.006). The intervention effect was attenuated after one year, and use of hypnotics was found to increase by 0.2% per month after March 2010. Following the second intervention in June 2012, there was a further significant decline in use of 0.18% each month over the 12 months of follow up (p = 0.049). The cumulative effect of both interventions resulted in 20,850 fewer patient-months of treatment with hypnotics. This cumulative reduction in hypnotic use was estimated to lead to a minimum of 1 fewer hospital admissions for acute confusion and 7 fewer hospital admissions due to falls.

CONCLUSIONS

The Veterans' MATES insomnia interventions which involved multiple stakeholders were effective in reducing hypnotic use among older Australians. Repetition of key messages led to sustained practice change.

Do Risk Prediction Models for Postoperative Delirium Consider Patients' Preoperative Medication Use?

BACKGROUND

Medicines are potentially modifiable risk factors for postoperative delirium. However, the extent to which preoperative medicines are included in risk prediction models (RPMs) is unknown.

OBJECTIVE

This systematic review aimed to assess the extent of inclusion of preoperative medications in RPMs for postoperative delirium.

METHODS

Articles were systematically searched from MEDLINE, EMBASE and CINAHL using Medical Subject Headings (MeSH) where possible and keywords for postoperative delirium and prediction model. Studies published until May 2017 with a primary outcome of postoperative delirium that developed an RPM containing preoperative patient information were considered. Where a study had two cohorts, a derivation and a validation cohort, findings from the derivation cohort were extracted and reported.

RESULTS

Eighteen prospective and one retrospective cohort studies were included for review. Of the 19 studies, only nine considered preoperative medication data, with medications appearing as predictor variables in five models. There was wide variability in the factors included in the final models, with the most frequent predictors being age and cognitive impairment, appearing in 13 (68%) and 11 (58%) RPMs, respectively.

CONCLUSION

While medications are commonly cited risk factors for delirium, they are not adequately considered when developing RPMs. Future studies aiming to develop an RPM for postoperative delirium should include preoperative medication data as a potential predictor variable because of the modifiable nature of medication use and its impact on other factors commonly in models, such as cognition.

The validity of the Rx-Risk Comorbidity Index using medicines mapped to the Anatomical Therapeutic Chemical (ATC) Classification System

OBJECTIVES

To provide a map of Anatomical Therapeutic Chemical (ATC) Classification System codes to individual Rx-Risk comorbidities and to validate the Rx-Risk Comorbidity Index.

DESIGN

The 46 comorbidities in the Rx-Risk Index were mapped to dispensing's indicative of each condition using ATC codes. Prescription dispensing claims in 2014 were used to calculate the Rx-Risk. A baseline logistic regression model was fitted using age and gender as covariates. Rx-Risk was added to the base model as an (1) unweighted score, (2) weighted score and as (3) individual comorbidity categories indicating the presence or absence of each condition. The Akaike information criterion and c-statistic were used to compare the models.

SETTING

Models were developed in the Australian Government Department of Veterans' Affairs health claims data, and external validation was undertaken in a 10% sample of the Australian Pharmaceutical Benefits Scheme Data.

PARTICIPANTS

Subjects aged 65 years or older.

OUTCOME MEASURES

Death within 1 year (eg, 2015).

RESULTS

Compared with the base model (c-statistic 0.738, 95% CI 0.734 to 0.742), including Rx-Risk improved prediction of mortality; unweighted score 0.751, 95% CI 0.747 to 0.754, weighted score 0.786, 95% CI 0.782 to 0.789 and individual comorbidities 0.791, 95% CI 0.788 to 0.795. External validation confirmed the utility of the weighted index (c-statistic=0.833).

CONCLUSIONS

The updated Rx-Risk Comorbidity Score was predictive of 1-year mortality and may be useful in practice to adjust for confounding in observational studies using medication claims data.

Preoperative medication use and postoperative delirium: a systematic review

BACKGROUND

Medications are frequently reported as both predisposing factors and inducers of delirium. This review evaluated the available evidence and determined the magnitude of risk of postoperative delirium associated with preoperative medication use.

METHODS

A systematic search in Medline and EMBASE was conducted using MeSH terms and keywords for postoperative delirium and medication. Studies which included patients 18 years and older who underwent major surgery were included. The methodological quality of included studies was assessed independently by two authors using the Newcastle-Ottawa quality assessment scale for cohort studies.

RESULTS

Twenty-nine studies; 25 prospective cohort, three retrospective cohort and one post hoc analysis of RCT data were included. Only four specifically aimed to assess medicines as an independent predictor of delirium, all other studies included medicines among a number of potential predictors of delirium. Of the studies specifically testing the association with a medication class, preoperative use of beta-blockers (OR = 2.06[1.18-3.60]) in vascular surgery and benzodiazepines RR 2.10 (1.23-3.59) prior to orthopedic surgery were significant. However, evidence is from single studies only. Where medicines were included as one possible factor among many, hypnotics had a similar risk estimate to the benzodiazepine study, with one significant and one non-significant result. Nifedipine use prior to cardiac surgery was found to be significantly associated with delirium. The non-specific grouping of psychoactive medication use preoperatively was generally higher with an associated two-to-seven-fold higher risk of postoperative delirium, while only two studies included narcotics without other agents, with one significant and one non-significant result.

CONCLUSIONS

There was a limited number of high quality studies in the literature quantifying the direct association between preoperative medication use and postsurgical delirium. More studies are required to evaluate the association of specific preoperative medications on the risk of postoperative delirium so that comprehensive guidelines for medicine use prior to surgery can be developed to aid delirium prevention.

TRIAL REGISTRATION

This systematic review has been registered on PROSPERO International prospective register of systematic reviews (Registration number: CRD42016051245 ).

Current practice and opinions of hospital pharmacists regarding their role in the screening, prevention and treatment of delirium

Background An interdisciplinary approach is fundamental for effective prevention and treatment of delirium. Pharmacists could play a role in identifying and resolving medication-related delirium. However, little is known about their role in delirium care. Objective The main purpose of this survey was to assess the current practice and opinions of pharmacists concerning their involvement in screening, prevention and treatment of delirium. Setting Pharmacists in public and private hospitals in Australia. Method A cross-sectional survey was conducted using a pilot tested web-based questionnaire which was distributed primarily via a link in the electronic newsletter of the Society of Hospital Pharmacists of Australia. Main outcome measure Number and proportion of respondents answering questions related to the practice and perceptions of pharmacists in delirium management. Results Responses from 106 pharmacists were included in the analysis. Most respondents believed that pharmacists could play a role in prevention (92%) and screening (62%) of patients for delirium. However, in practice only 8% of pharmacists reported that they had ever screened a patient for delirium using a validated tool and 79% indicated that pharmacists were never or rarely involved in delirium treatment. When pharmacists did make recommendations half of the respondents said that pharmacists' recommendations were frequently or always accepted by the delirium treating teams. Conclusion Hospital pharmacists are underutilised in the prevention and management of delirium. Strategies to increase their involvement in the prevention and management of delirium should be implemented.

Apixaban, concomitant medicines and spontaneous reports of haemorrhagic events

INTRODUCTION

Little is known about the potential safety issues associated with apixaban in clinical practice and their reporting in spontaneous adverse event (SAE) databases.

OBJECTIVE

To describe SAE reports associated with the oral anticoagulant apixaban from Australia, Canada and USA and to examine associated concomitant medicine use.

METHODS

SAE report databases from Australia, Canada and the USA were examined for all reports of adverse events associated with apixaban and concomitant medicines from 1 January 2012 to 30 September 2014. Disproportionality analysis (proportional reporting ratio (PRR) and reporting odds ratio (ROR)) was conducted for the quantitative detection of signals using the USA database.

RESULTS

There were 97 SAE reports associated with apixaban from Australia, 77 from Canada and 2877 from the USA. Reporting of haemorrhage (any type) was common, ranging from 18% for USA to 31% for Australia. Gastrointestinal (GI) haemorrhage was the most commonly reported haemorrhage, accounting for approximately 10% of adverse event reports across all countries. Positive signals were confirmed in the USA data (haemorrhage (any type) PRR, 12.1; χ², 5582.2 and ROR, 13.4; 95% CI: 12.13-14.6; GI haemorrhage PRR, 11.8; χ², 2325.4 and ROR, 12.3; 95% CI, 10.8-14.0). Reporting of concomitant use of medicines with the potential to increase bleeding risk ranged from 47.6% in Canada to 65.5% in Australia.

CONCLUSION

A large proportion of adverse event reports for apixaban were associated with use of concomitant medicines which may have increased the risk of haemorrhage.

Suboptimal medication-related quality of care preceding hospitalisation of older patients

OBJECTIVE

To examine the prevalence of suboptimal medication-related processes of care before the hospitalisation of older patients.

DESIGN AND SETTING

We conducted a retrospective cohort study using a clinical indicator set related to medication management that has been validated by an expert panel as consisting of suboptimal aspects of medication use that clinicians should be able to foresee and avoid. Australian Government Department of Veterans' Affairs administrative claims data between 1 July 2007 and 30 June 2012 were analysed according to these clinical indicators to assess medication-related processes of care preceding hospitalisation.

PARTICIPANTS

Veterans with one or more hospitalisations in Australia for a condition defined by the clinical indicator set.

MAIN OUTCOME MEASURE

Prevalence of suboptimal medication-related processes of care before hospitalisation as a proportion of all hospitalisations defined by diagnoses in the clinical indicator set.

RESULTS

During the 5-year study period, there were 164,813 hospitalisations with primary diagnoses for conditions included in the clinical indicator set, encompassing 83,430 patients. The overall proportion of hospitalisations that were preceded by suboptimal medication-related processes of care was 25.2% (41,546 hospitalisations); 34.5% of patients (28,807 patients) had at least one hospitalisation and 10.4% (8640 patients) had two or more hospitalisations preceded by suboptimal medication-related processes of care. At least one in 10 hospitalisations for chronic heart failure, ischaemic stroke, asthma, gastrointestinal ulcer or bleeding, fracture, renal failure or nephropathy, hyperglycaemia or hypoglycaemia were preceded by suboptimal medication-related processes of care.

CONCLUSIONS

This study highlights conditions for which there are evidence-practice gaps in medication management in the older population. Routine prospective monitoring of these evidence-based, validated, medication-related clinical indicators provides a means for quality improvement in the management of common chronic conditions.

Commitment questions targeting patients promotes uptake of under-used health services: Findings from a national quality improvement program in Australia

RATIONALE

Interventions asking patients to commit to speaking with their doctor about a health-related issue could be used to improve quality of care.

OBJECTIVE

To evaluate the impact of commitment questions targeting patients on the uptake of recommended health services within a national quality improvement program (Veterans' MATES).

METHODS

Patients targeted in the home medicines reviews (HMRs), dose administration aids (DAAs), renal function testing and diabetes interventions were posted educational information and response forms which asked whether they intended to talk to their general practitioner (GP) about the targeted service. Uptake of the service after each intervention was determined using health claims data. Log binomial regression models compared the monthly rate of service use in the nine months post-intervention among patients answering 'yes' to a commitment question with non-responders and patients answering 'no' or 'unsure'.

RESULTS

Each intervention targeted up to 58,000 patients. The average response rate was 28%. Positive responses were associated with increased uptake of HMRs (rate ratio (RR) 2.64, 95% CI 2.39-2.92; p < 0.0001), dose administration aids (RR 2.53, 95% CI 2.29-2.79; p < 0.0001), renal function tests (RR 1.18, 95% CI 1.13-1.24; p < 0.0001), GP management plans (RR 1.30, 95% CI 1.14-1.48; p < 0.0001) and diabetes care plans (RR 1.47, 95% CI 1.24-1.75; p < 0.0001) compared to non-responders. Similar increases in uptake were also observed among positive responders when compared to patients responding 'no' or 'unsure' to the commitment question.

CONCLUSION

Positive responses to commitment questions distributed as part of national, multifaceted interventions were consistently associated with increased uptake of targeted services.

A cross-country comparison of rivaroxaban spontaneous adverse event reports and concomitant medicine use with the potential to increase the risk of harm

BACKGROUND

Concerns with the safety profiles of the newer anticoagulants have been raised because of differences in treatment populations between pre-marketing studies (randomized controlled trials) and clinical practice. Little is known about the potential safety issues and the reporting in spontaneous adverse event databases associated with rivaroxaban.

OBJECTIVES

To analyse spontaneous adverse event reports associated with the oral anticoagulant rivaroxaban from Australia, Canada and the USA; and to examine concomitant medicine use that may increase the risk of adverse events.

METHODS

Spontaneous adverse event report databases from Australia, Canada and the USA were examined for all reports of adverse events associated with rivaroxaban and concomitant medicines from 1 August 2005 to 31 March 2013. Disproportionality analysis (the proportional reporting ratio [PRR] and reporting odds ratio [ROR]) was conducted for quantitative detection of signals, using the US database.

RESULTS

There were 244 spontaneous adverse event reports associated with rivaroxaban from Australia, 536 from Canada and 1,638 from the USA. Reporting of haemorrhage (any type) was common, ranging from 30.7% for Australia to 37.5% for Canada. Gastrointestinal haemorrhage was the most commonly reported haemorrhage, accounting for 13.9% of Australian, 16.4% of Canadian and 11.1% of US adverse event reports. Positive signals were confirmed in the US data (haemorrhage [any type] PRR 11.93, χ (2) 4,414.78 and ROR 13.41, 95% confidence interval [CI] 12.13-14.81; gastrointestinal haemorrhage PRR 12.52, χ (2) 2,018.48 and ROR 13.15, 95% CI 11.36-15.21). Reporting of concomitant use of medicines with the potential to increase bleeding risk ranged from 63.7% in Australia to 89.2% in Canada.

CONCLUSION

A large proportion of adverse event reports for rivaroxaban were associated with use of concomitant medicines, which may have increased the risk of adverse events-in particular, haemorrhage. Increased awareness of a patient's comorbidity and associated medicine use is needed when rivaroxaban is used in clinical practice.

Association between use of multiple psychoactive medicines and hospitalization for falls: retrospective analysis of a large healthcare claim database

Background

Little is known about the impact of taking multiple psychoactive medicines on the risk of hospitalization for falls.

Objective

To identify the association between multiple psychoactive medicine use and hospitalization for falls.

Methods

A retrospective cohort study was conducted between July 2011 and June 2012 in the Australian veteran population who had been dispensed at least one psychoactive medicine within the previous year. Psychoactive medicines with sedative properties included antipsychotics, anxiolytics, hypnotics, antidepressants, opioids, anti-epileptics, anti-Parkinson medicines and medicines for migraine. The associations between falls and the number of psychoactive medicines used or the number of doses were analysed in comparison with falls that occurred when no psychoactive medicine was used.

Results

The adjusted results showed a significantly increased risk of falls when patients were on one or more psychoactive medicines or were receiving 0.1–0.9 defined daily dose (DDD) or more per day. The incident rate ratios (IRRs) were 1.22 (95 % confidence interval [CI] 1.08–1.38) for those on one psychoactive medicine, 1.70 (95 % CI 1.45–1.99) for those on two, 1.96 (95 % CI 1.58–2.43) for those on three or four, and 3.15 (95 % CI 1.90–5.23) for those on five or more. A similar result was observed when the data were analysed by dose, with the highest risk being found for those taking three or more DDD per day (adjusted IRR 4.26, 95 % CI 2.75–6.58).

Conclusion

Increased numbers or increased doses of psychoactive medicines are associated with an increased risk of hospitalization for falls in older adults. Strategies to reduce the psychoactive medicine burden are likely to translate into significant health benefits.

Multiple anticholinergic medication use and risk of hospital admission for confusion or dementia

OBJECTIVES

To identify the association between use of multiple anticholinergic medications and risk of hospitalization for confusion or dementia.

DESIGN

Retrospective cohort study conducted over 2 years between July 2010 and June 2012, using administrative claims data from the Australian Department of Veterans' Affairs.

SETTING

Australia.

PARTICIPANTS

Australian veterans dispensed at least one moderately or highly anticholinergic medication in the year before study start.

MEASUREMENTS

Cumulative anticholinergic use on each day of the study period was determined. The association between hospitalization for confusion or dementia and number of anticholinergic medications used at the time of admission was compared against times during which participants were not taking anticholinergic medications. Sensitivity analyses were undertaken limiting the outcome to admissions for acute confusion and excluding individuals taking antipsychotics.

RESULTS

Adjusted results showed a significantly greater risk of hospitalization for confusion or dementia when individuals were taking two or more anticholinergic medications. The adjusted incident rate ratios (IRRs) were 2.58 (95% confidence interval (CI) = 1.91-3.48) for those taking two anticholinergics and 3.87 (95% CI = 1.83-8.21) for those taking three or more. Sensitivity analyses in which participants taking antipsychotic medications were excluded and the outcome was limited to acute confusion also found similar risks for those taking two (IRR 1.82, 95% CI = 1.18-2.80) and three or more (IRR = 3.98 95% CI = 1.50-10.58) anticholinergic medications.

CONCLUSION

Taking more anticholinergic medications is associated with greater risk of hospitalization for confusion or dementia. Strategies to reduce anticholinergic medication burden are likely to translate into significant health benefits.

An international comparison of spontaneous adverse event reports and potentially inappropriate medicine use associated with dabigatran

PURPOSE

The objective of this study was to analyse spontaneous adverse event (SAE) reports associated with the oral anticoagulant dabigatran from Australia, Canada and USA and to examine concomitant medicine use.

METHODS

Spontaneous adverse event national databases from Australia, Canada and the USA were used to examine all reports of adverse events associated with dabigatran from 1st August 2005 to 31st March 2013. Disproportionality analysis was conducted for the quantitative detection of signals using the USA database. Concomitant medicine use was examined to identify potentially inappropriate medicines, which may place the patient at increased risk for adverse events.

RESULTS

There were a total of 1039, 1333 and 13 788 SAE reports associated with dabigatran from Australia, Canada and USA, respectively. Gastrointestinal (GI) disorders were the most commonly reported adverse event, ranging from 27.5% for Australia and up to 40.5% for USA. Of these, GI haemorrhage accounted for 81.5% of Australian, 71.5% of Canadian and 42% of the USA adverse event reports for GI disorders. Positive signals were confirmed in the USA data (GI haemorrhage; PRR 18.18, χ2 40993.51 and ROR 19.55 95% CI 18.77-20.36). Use of concomitant medicines with the potential to increase bleeding risk across all three countries ranged from 34.1% for Australia to 51.1% for the USA.

CONCLUSIONS

A large proportion of adverse events were associated with concomitant therapies, which may have placed the patient at increased risk of harm. This highlights the need for pharmacovigilance by the prescribing clinician to minimise risk and ensure the safe and effective integration of dabigatran into routine clinical practice.

Development of evidence-based Australian medication-related indicators of potentially preventable hospitalisations: a modified RAND appropriateness method

OBJECTIVE

Indicators of potentially preventable hospitalisations have been adopted internationally as a measure of health system performance; however, few assess appropriate processes of care around medication use, that if followed may prevent hospitalisation. The aim of this study was to develop and validate evidence-based medication-related indicators of potentially preventable hospitalisations.

SETTING

Australian primary healthcare.

PARTICIPANTS

Medical specialists, general practitioners and pharmacists. A modified RAND appropriateness method was used for the development of medication-related indicators of potentially preventable hospitalisations, which included a literature review, assessment of the strength of the supporting evidence base, an initial face and content validity by an expert panel, followed by an independent assessment of indicators by an expert clinical panel across various disciplines, using an online survey.

PRIMARY OUTCOME MEASURE

Analysis of ratings was performed on the four key elements of preventability; the medication-related problem must be recognisable, the adverse outcomes foreseeable and the causes and outcomes identifiable and controllable.

RESULTS

A total of 48 potential indicators across all major disease groupings were developed based on level III evidence or greater, that were independently assessed by 78 expert clinicians (22.1% response rate). The expert panel considered 29 of these (60.4%) sufficiently valid. Of these, 21 (72.4%) were based on level I evidence.

CONCLUSIONS

This study provides a set of face and content validated indicators of medication-related potentially preventable hospitalisations, linking suboptimal processes of care and medication use with subsequent hospitalisation. Further analysis is required to establish operational validity in a population-based sample, using an administrative health database. Implementation of these indicators within routine monitoring of healthcare systems will highlight those conditions where hospitalisations could potentially be avoided through improved medication management.

Bridging evidence-practice gaps: improving use of medicines in elderly Australian veterans

Background

The Australian Government Department of Veterans’ Affairs (DVA) funds an ongoing health promotion based program to improve use of medicines and related health services, which implements interventions that include audit and feedback in the form of patient-specific feedback generated from administrative claims records. We aimed to determine changes in medicine use as a result of the program.

Methods

The program provides targeted patient-specific feedback to medical practitioners. The feedback is supported with educational material developed by a clinical panel, subject to peer review and overseen by a national editorial committee. Veterans who meet target criteria also receive educational brochures. The program is supported by a national call centre and ongoing national consultation. Segmented regression analyses (interrupted time series) were undertaken to assess changes in medication use in targeted veterans pre and post each intervention.

Results

12 interventions were included; three to increase medicine use, seven which aimed to reduce use, and two which had combination of messages to change use. All programs that aimed to increase medicine use were effective, with relative effect sizes at the time of the intervention ranging from 1% to 8%. Mixed results were seen with programs aiming to reduce inappropriate medicine use. Highly specific programs were effective, with relative effect sizes at the time of the intervention of 10% decline in use of NSAIDs in high risk groups and 14% decline in use of antipsychotics in dementia. Interventions targeting combinations of medicines, including medicine interactions and potentially inappropriate medicines in the elderly did not change practice significantly. Interventions with combinations of messages targeting multiple components of practice had an impact on one component, but not all components targeted.

Conclusions

The Veterans’ MATES program showed positive practice change over time, with interventions increasing use of appropriate medicines where under-use was evident and reduced use of inappropriate medicines when single medicines were targeted. Combinations of messages were less effective, suggesting specific messages focusing on single medicines are required to maximise effect. The program provides a model that could be replicated in other settings.