Ethnic inequality in non-steroidal anti-inflammatory drug-associated harm in New Zealand: A national population-based cohort study.

PURPOSE: Non-steroidal anti-inflammatory drugs (NSAIDs) are associated with many serious complications and they are widely used in New Zealand (NZ). However, differences in NSAID-associated risk for these complications between ethnic groups are largely unknown. We assessed ethnic disparities in risk of hospital admission for upper gastrointestinal bleeding (UGIB), heart failure, and acute kidney failure (AKF) in NZ's primary care population prescribed and dispensed NSAIDs. METHODS: Retrospective cohort study utilising national pharmaceutical dispensing and hospital admissions data 2007 to 2015. Patient follow-up included 90-day periods following the dispensing of NSAIDs. Risk for each adverse outcome in Maori, Pacific, European, and Asian patients was estimated using multivariable Poisson regression adjusting for age, sex, deprivation, comorbidity and concurrent drug use. RESULTS: 3 023 067 patients were dispensed NSAIDs between 2008 and 2015. Their total intended duration of NSAID treatment encompassed 2 353 140 patient-years. Maori, Pacific and Asian patients were younger than European patients (all P < .001). After adjusting for other risk factors, Maori (rate ratio: 2.54, 95% confidence interval: 2.23-2.90) and Pacific patients (3.17, 2.69-3.74) were more likely to be hospitalised for UGIB than Europeans (reference), and heart failure (Maori: 2.48, 2.24-2.74; Pacific: 1.97, 1.69-2.30). Risk of AKF was higher in Maori (1.46, 1.23-1.74). Higher risk for UGIB and HF in Maori and Pacific patients was most pronounced in males and patients aged <60 years. CONCLUSIONS: Inequalities exist in the incidence of serious adverse outcomes experienced by different ethnic groups in NZ while using NSAIDs. Interventions to promote safer use of these medicines are required to reduce this inequity.

Correcting for Body Surface Area Identifies the True Prevalence of Abdominal Aortic Aneurysm in Screened Women.

OBJECTIVE: Recently, the prevalence of abdominal aortic aneurysm (AAA) using screening strategies based on elevated cardiovascular disease (CVD) risk was reported. AAA was defined as a diameter ≥30 mm, with prevalence of 6.1% and 1.8% in men and women respectively, consistent with the widely reported AAA predominant prevalence in males. Given the obvious differences in body size between sexes this study aimed to re-evaluate the expanded CVD risk based AAA screening dataset to determine the effect of body size on sex specific AAA prevalence. METHODS: Absolute (26 and 30 mm) and relative (aortic size index [ASI] equals the maximum infrarenal aorta diameter (cm) divided by body surface area (m2), ASI ≥ 1.5) thresholds were used to assess targeted AAA screening groups (n = 4115) and compared with a self reported healthy elderly control group (n = 800). RESULTS: Male AAA prevalence was the same using either the 30 mm or ASI ≥1.5 aneurysm definitions (5.7%). In females, AAA prevalence was significantly different between the 30 mm (2.4%) and ASI ≥ 1.5 (4.5%) or the 26 mm (4.4%) thresholds. CONCLUSION: The results suggest the purported male predominance in AAA prevalence is primarily an artefact of body size differences. When aortic size is adjusted for body surface area there is only a modest sex difference in AAA prevalence. This observation has potential implications in the context of the ongoing discussion regarding AAA screening in women.

Prevalence and risk factors for chronic kidney disease in primary health care in the southern region of New Zealand.

AIM: While the prevalence of end stage kidney disease in New Zealand (NZ) is well defined, the prevalence of chronic kidney disease (CKD) in NZ is unknown. To estimate the prevalence of and risk factors for CKD in the southern region of New Zealand. METHODS: A retrospective electronic health record cohort study using data from the Southern Primary Care register covering 94% of the population. Patients, 20 years or older were identified and linked to laboratory results for serum creatinine and urinary albumin excretion. Chronic kidney disease was defined as an estimated glomerular filtration rate of less than 60 mL/min per 1.73 m2 (G3-5) or the presence of albuminuria of greater than 3 mg/mmol (A2-3). Diabetes was identified from a national virtual diabetes database. From this, we estimated the prevalence of CKD by age, gender, ethnicity, deprivation and the presence of diabetes mellitus. RESULTS: Of a total adult population of 211 980, 159 799 had a serum creatinine checked and 27 905 had an estimate of albuminuria. The estimated prevalence of CKD was 11.8%. 6.3% of total population had CKD stage G3a, 2.4% G3b, 0.8% G4, 0.2% G5, 1.8% A2 albuminuria and 0.3% A3 albuminuria. Increasing age, female sex, ethnic group, social deprivation and diabetes mellitus were associated with an increased risk of CKD. 11 351 patients had a diagnosis of diabetes mellitus and were almost universally tested (99.3%) for CKD. The presence of albuminuria was strongly correlated with ethnic group, male sex and living in a deprived area. The retrospective electronic health record study with associated selection and testing bias are potential limitations of the present study. CONCLUSION: Chronic kidney disease prevalence in this region appears to be similar to other reported populations. The majority of those at risk for CKD were tested for reduced eGFR. The presence of albuminuria, an integral component of CKD diagnostic criteria, was under utilized in the non-diabetic population.

Understanding medicines with a propensity to increase the risk of heart failure: Combining existing knowledge with targeted population assessment.

PURPOSE: Existing knowledge of medicines that increase the risk of an adverse event may be corroborated and augmented by population studies specifically assessing the risk associated with the concurrent use of these medicines and use by patients with existing comorbidity. An American Heart Association review recently identified a variety of medicines that may cause or exacerbate heart failure (HF), many with evidence from limited evaluation of population data. We assessed the risk of first-time HF associated with the use of 50 of these medicines by New Zealand's primary care population. METHODS: Case-control study utilising national pharmaceutical use and hospital admissions data 2007-2015; 22,989 patients with first-time HF 2008-2015 were matched with 114 498 control patients. The primary outcome was first-time HF and its association with medicine exposure in the prior 90 days, estimated using conditional logistic regression. We also assessed the risk associated with new use of medicines in the prior month, concurrent use, and in patients with existing comorbidity. RESULTS: Eleven medicines were significantly associated with HF with several other infrequently used medicines providing signals of increased risk. A high risk was associated with the use of salbutamol (adjusted odds ratio 2.63; 95% CI, 2.48-2.78), clozapine (2.70; 2.46-4.98), diltiazem (1.52; 1.44-1.60), indomethacin (2.51; 1.54-4.10), pioglitazone (1.50; 1.16-1.95), and antifungal medicines. New use of medicines and use of medicine combinations increased this risk in many cases. CONCLUSIONS: Our study provides further evidence to inform cautious use of these medicines in patients with HF or at risk of developing HF.

Impact of General Practitioner Transient Ischemic Attack Training on 90-Day Stroke Outcomes: Secondary Analysis of a Cluster Randomized Controlled Trial.

GOALS: Many patients with transient ischemic attack (TIA) receive initial assessments by general practitioners (GPs) who may lack TIA management experience. In a randomized controlled trial (RCT), we showed that electronic decision support for GPs improves patient outcomes and guideline adherence. Some stroke services prefer to improve referrer expertise through TIA/stroke education sessions instead of promoting TIA decision aids or triaging tools. This is a secondary analysis of whether a GP education session influenced TIA management and outcomes. MATERIALS AND METHODS: Post hoc analysis of a multicenter, single blind, parallel group, cluster RCT comparing TIA/stroke electronic decision support guided GP management with usual care to assess whether a pretrial TIA/stroke education session also affected RCT outcomes. FINDINGS: Of 181 participating GPs, 79 (43.7%) attended an education session and 140 of 291 (48.1%) trial patients were managed by these GPs. There were fewer 90-day stroke events and 90-day vascular events or deaths in patients treated by GPs who attended education; 2 of 140 (1.4%) and 10 of 140 (7.1%) respectively, compared with those who did not; 5 of 151 (3.3%), and 14 of 151 (9.3%), respectively. Logistic regression for association between 90-day stroke and 90-day vascular events or death and education, however, was nonsignificant (odds ratio [OR] .42 (.08 to 2.22), P = .29 and .59 (95% confidence interval [CI] .27 to 1.29), P = .18 respectively. Guideline adherence was not improved by the education session: OR .84 (95% CI .49 to 1.45), P = .54. CONCLUSION: In the described setting, a GP TIA/stroke education session did not significantly enhance guideline adherence or reduce 90-day stroke or vascular events following TIA.

Variation in the pharmaceutical costs of New Zealand general practices: a national database linkage study.

BACKGROUND: Variation in prescription costs between general practices and within practices over time is poorly understood. METHODS: From New Zealand's national health data collections, we extracted dispensed medicines data for 1045 general practices in 2011 and 917 practices continuously existing 2008-11. Using indirect standardization to account for patient demographics and morbidity, a standardized prescribing cost ratio (SPR: the ratio of actual : expected prescription costs) was calculated for each practice in each year. Case studies of three outlier clinics explored reasons for their status. RESULTS: SPRs ranged from 0.53 to 2.28 (median = 0.98). Of 469 practices with higher than expected costs (SPR > 1.0) in 2011, 204 (43.5%) had a single medicine or therapeutic drug class accounting for >15% of total costs. Case studies contrasted practices with overall pharmaceutical expenditure influenced strongly by a few patients needing high-cost medicines, more patients using medicines in one high-cost therapeutic drug class (antiretrovirals), and high medicine use across all therapeutic drug classes. CONCLUSIONS: Routine data collections can measure inter-practice variation in prescription costs, adjusted for differences in the demography and morbidity profile of each practice's patients. Small groups of patients using high-cost medicines influence general practices' expenditure on pharmaceuticals.

Ethnic disparities in asthma treatment and outcomes in children aged under 15 years in New Zealand: analysis of national databases.

BACKGROUND: Mãori and Pacific children experience poorer outcomes relating to asthma management than other ethnicities. AIMS: To measure recommended treatment and outcomes for asthma in all New Zealand children by age, sex, and ethnic group. METHODS: Children aged <15 years dispensed >2 asthma medicines (N=80,514) were identified from the national pharmaceutical claims database. We measured the number of children dispensed oral steroids >2 times and hospital admissions with a primary diagnosis of asthma and compared asthma treatment steps and hospitalisation by age and ethnicity. RESULTS: 16.0% of children were dispensed asthma medicines, 9.2% were dispensed medicine >2 times, 3.6% of children were hospitalised at least once for asthma and 98.9% of admissions were acute. Mãori (OR 1.46, 95% CI 1.41 to 1.51) and Pacific children (OR 2.38, 95% CI 2.28 to 2.47) were more likely to remain on the lowest step of treatment. At all steps of treatment, Mãori and Pacific children had higher rates of oral steroid use. In all age groups, more Mãori children (5.1%, OR 1.88, 95% CI 1.73 to 2.04) and Pacific children (5.6%, OR 2.05, 95% CI 1.84 to 2.29) were hospitalised for asthma than children of other ethnicities (2.8%). CONCLUSIONS: Mãori and Pacific children are less likely to have their treatment escalated to a higher step than other children. They are also more likely to use oral steroids to control asthma exacerbations and be admitted to hospital for severe asthma episodes. New Zealand databases can be used to monitor these outcomes.

Epidemiology of healthcare harm in New Zealand general practice: a retrospective records review study.

OBJECTIVES: To determine the epidemiology of healthcare harm observable in general practice records. DESIGN: Retrospective cohort records review study. SETTING: 72 general practice clinics were randomly selected from all 988 New Zealand clinics stratified by rurality and size; 44 clinics consented to participate. PARTICIPANTS: 9076 patient records were randomly selected from participating clinics. INTERVENTION: Eight general practitioners examined patient records (2011-2013) to identify harms, harm severity and preventability. Analyses were weighted to account for the stratified sampling design and generalise findings to all New Zealand patients. MAIN OUTCOME MEASURES: Healthcare harm, severity and preventability. RESULTS: Reviewers identified 2972 harms affecting 1505 patients aged 0-102 years. Most patients (82.0%, weighted) experienced no harm. The estimated incidence of harm was 123 per 1000 patient-years. Most harms (2160; 72.7%, 72.4% weighted) were minor, 661 (22.2%, 22.8% weighted) were moderate, and 135 (4.5%, 4.4% weighted) severe. Eleven patients died, five following a preventable harm. Of the non-fatal harms, 2411 (81.6%, 79.4% weighted) were considered not preventable. Increasing age and number of consultations were associated with increased odds of harm. Compared with patients aged ≤49 years, patients aged 50-69 had an OR of 1.77 (95% CI 1.61 to 1.94), ≥70 years OR 3.23 (95% CI 2.37 to 4.41). Compared with patients with ≤3 consultations, patients with 4-12 consultations had an OR of 7.14 (95% CI 5.21 to 9.79); ≥13 consultations OR 30.06 (95% CI 21.70 to 41.63). CONCLUSIONS: Strategic balancing of healthcare risks and benefits may improve patient safety but will not necessarily eliminate harms, which often arise from standard care. Reducing harms considered 'not preventable' remains a laudable challenge.

Reduced community antibiotic dispensing in New Zealand during 2015-2018: marked variation in relation to primary health organisation.

AIMS: The overall rate of community antibiotic dispensing in New Zealand in recent decades has been high when compared with many other nations, but since 2015 has consistently declined each year. We aimed to determine whether the magnitude of reductions in community antibiotic dispensing in New Zealand between 2015 and 2018 differed in relation either to the patient's demographic features or in relation to the primary health organisation of the patient's registered general practitioner. METHODS: Demographic data on all patients registered with a general practice in New Zealand, and on all community pharmacy antibiotic dispensing for these patients during 2013-2018 were obtained from national healthcare databases. The rates of dispensing for patients registered with a general practitioner were measured as antibiotic courses dispensed per 1,000 population per day, and as defined daily doses per 1,000 population per day. RESULTS: Total community antibiotic dispensing in New Zealand, measured as defined daily doses per 1,000 inhabitants per day, decreased by 13.8% during 2015-2018, an average annual reduction of 4.6% per year, with especially large reductions in dispensing of amoxicillin/clavulanate, fluoroquinolones and macrolides. The reductions in dispensing were greatest in children aged 0-4 years old, but lesser reductions were seen in all age groups. Antibiotic dispensing declined regardless of patient ethnicity or level of socioeconomic deprivation. There were marked differences between primary health organisations in the size of the reductions in antibiotic dispensing during 2015-2018, which ranged between 4.8% for the Te Tai Tokerau PHO to 21.5% for the Ngati Porou Hauora Charitable Trust PHO. CONCLUSIONS: Total community antibiotic dispensing has reduced significantly in New Zealand between 2015 and 2018, with large disparities between primary health organisations in the size of the reductions. The overall rates of antibiotic dispensing remain high for non-Maori and non-Pacific people, and prescribers should aim to further reduce inappropriate antibiotic prescribing for these populations. However, the overall rate of antibiotic dispensing for Maori and Pacific people may now approximate an optimal level. Prescribers should aim to further reduce inappropriate antibiotic prescribing, but also to increase appropriate antibiotic prescribing for these populations.

Trends in prescription medicine use by older people in New Zealand 2010- 2015: a national population-based study.

BACKGROUND: Research investigating trends in the general prescription medicine use of older people in New Zealand is limited. AIM: To examine trends in the use of outpatient medicines by older adults and assess changing patterns in use from 2010 to 2015. METHODS: A retrospective cohort study including all New Zealand primary care patients over 65 years of age utilising data from the national pharmaceutical claims database. We calculated the prevalence of use within three age groups and by sex in each year by anatomical therapeutic class, therapeutic group and individual medicine. Rate ratios were calculated to compare the prevalence of use in 2010 and 2015. RESULTS: The study included 829,026 patients with a mean of 4.4 years of potential drug exposure. Overall prevalence of medicine use was 92% in 2010 and 93% in 2015. The mean number of prescriptions per patient-year for patients >=85 years of age (39.2) was almost double that of patients 65-74 years (21.8). Prevalence of use was similar between females (94%) and males (92%). Antibacterials, analgesics, cardiovascular drugs and proton pump inhibitors were the most widely used medicines. The use of systemic antibiotics increased by 2% between 2010 and 2015, but there were significant decreases in use of antithrombotics (6%), beta blockers (6%), diuretics (19%), nitrates (19%) and antiarrhythmics (24%). CONCLUSION: Our findings indicate both positive changes in response to guidance on safe and appropriate medicine use and several areas of concern. Continued monitoring of changing patterns in the medicine use of older people will be important, particularly with regard to the use of combinations of medicines that increase their risk of adverse events.

Fatal Toxicity Indices for Medicine-Related Deaths in New Zealand, 2008-2013.

INTRODUCTION: The fatal toxicity index (FTI) is a measure for assessing the relative risks of death due to the medicines prescribed in a population. This knowledge is useful for prescribers and informs medicine safety initiatives. This study aimed to calculate FTIs for the New Zealand population using three methodologies. METHODS: New Zealand coronial data describing medicine-related deaths from 1 January 2008 to 31 December 2013 were retrospectively extracted from the National Coronial Information System. Three fatal toxicity indices were derived using the number of deaths attributed to each pharmaceutical as the numerator and the total defined daily doses, number of patients and number of prescriptions as denominators. RESULTS: There were 703 medicine-related deaths, of which 627 were assessed as due to one primary contributor. Median decedent age was 48 years (interquartile range 37-58), and 319 (51%) were male. Deaths were intentional in 252 cases (40%), unintentional in 284 (45%) and unknown in 91 (15%). The majority of deaths (n = 486, 78%) occurred in the community. Opioids, antidepressants, antipsychotics and hypnotic-anxiolytics caused most fatalities. While the FTIs for individual medicines varied by denominator applied, methadone and clozapine fatalities were prominent in all three indices. The antidepressants clomipramine, dosulepin and doxepin consistently returned the highest FTIs in their group. CONCLUSION: New Zealand prescribers should be aware of the high relative risk of death associated with methadone and clozapine; that clomipramine, dosulepin and doxepin were identified as the most dangerous antidepressants; and that zopiclone carries a similar fatal risk to benzodiazepines. Varying results were found between the FTIs calculated, making comparisons, particularly between populations, difficult.

Deaths by poisoning in New Zealand, 2008-2013.

Introduction: While a number of developed countries have witnessed a decline in carbon monoxide (CO) deaths and increasing numbers of opioid-related fatalities, it is not known whether these or other trends have occurred in New Zealand. The aim of this study was, therefore, to review deaths due to poisoning in New Zealand, describe the causative substances, and identify any trends. Methods: Retrospective study reviewing New Zealand's poison-related death findings recorded in the National Coronial Information System (NCIS) database over the 6-year period 2008-2013. Results: We identified 1402 poisoning-related deaths recorded in the NCIS database representing a mortality rate of 5.4 deaths/100,000 population per year. The mortality rate due to poisoning was higher in males (6.96/100,000) than females (3.83/100,000). Fatalities peaked in the 40-50-year age group with the highest proportion of intentional deaths occurring in people aged 80-90 years. Pharmaceuticals accounted for 731 fatalities (52%) and chemicals 431 (31%), with multiple exposures occurring in 399 cases (28.5%). While CO was the leading cause of death throughout the period (n = 303, 21.6%), there was a significant reduction in the rate of CO fatalities from 1.69/100,000 population in 2008 to 0.94/100,000 in 2013 (IRR (95% CI) 2013/2008 0.56 (0.37-0.83)). There was, however, no statistically significant change in either the opioid-related death rate or the total number of deaths. Methadone was the leading pharmaceutical cause of fatality and the third most common cause overall, followed by morphine and codeine, with zopiclone and clozapine equally ranked as the sixth most common cause. Conclusion: While New Zealand has not suffered an "opioid epidemic" and has experienced a significant decline in CO deaths, the overall death rate due to poisoning has remained high. The development of accessible, timely, and relevant toxicovigilance systems would support the early implementation of interventions to reduce the leading causes of fatal poisoning.

Ethnic disparities in community antibacterial dispensing in New Zealand, 2015.

AIMS: There are significant ethnic disparities in the incidence of various infectious diseases in New Zealand. Antimicrobial stewardship interventions which ignore these disparities may have negative effects on the health of some ethnic groups. We aimed to determine the relationship between ethnicity and community antimicrobial dispensing in New Zealand, to inform the development of antimicrobial stewardship interventions in New Zealand. METHODS: Demographic data on all patients registered with a general practice in New Zealand and on all community pharmacy antibacterial dispensings during 2015 were obtained from national healthcare databases. The rates of dispensing were measured as the number of dispensings per 1,000 population per day and as defined daily doses per 1,000 population per day. RESULTS: The rate of community antibacterial dispensing for the total population surveyed was 3.01 dispensings per 1,000 population per day, and was 3.49 for Pacific, 3.23 for Maori, 3.02 for European, 2.70 for Middle Eastern, Latin American and African, and 2.35 for Asian people. In all ethnic groups the rate of community antibacterial dispensing increased with increasing socioeconomic deprivation. Seasonal variation in antibacterial dispensing ranged between 34% in Asian people and 24% in European people. CONCLUSIONS: The ethnic disparities in the rates of antibacterial dispensing in New Zealand are consistent with, but less marked than, the ethnic disparities in the incidence of infectious diseases in New Zealand. Improved community-wide understanding of both the benefits and the harms of antibacterial medicines is necessary to support improved antibacterial use in New Zealand in the future.

Trends in Outpatient Prescription Medicine Use in New Zealand Children 2010-2015: A National Population-Based Study.

BACKGROUND: Research examining trends in the outpatient prescription medicine use of New Zealand children is limited. OBJECTIVES: Our objective was to provide an overview of prescription medicine use in New Zealand children and assess changing patterns in use from 2010 to 2015. METHODS: We conducted a retrospective cohort study including all New Zealand primary care-registered children aged < 18 years using data from the national pharmaceutical claims database. We calculated the prevalence of use within four age groups in each year by anatomical therapeutic class, therapeutic group and drug. Rate ratios were calculated to compare the prevalence of use in 2010 and 2015. RESULTS: In total, 1,496,026 children with a mean of 2.7 years of potential drug exposure were included. The overall prevalence of drug use was 70% in 2010 and 73% in 2015. In 2015, medicine use was highest in children aged < 2 years (90%) and lowest in children aged 12-17 years (65%). Antibacterials, analgesics, topical corticosteroids, non-steroidal anti-inflammatory drugs (NSAIDs) and antihistamines were the most widely used medicines. The prevalence of use of systemic and topical antibiotics decreased by 2 and 10%, respectively, between 2010 and 2015, but there was increased use of analgesics (10%), NSAIDs (39%), antihistamines (15%) and antinausea and vertigo agents (306%). CONCLUSIONS: Our findings indicate areas for further research focusing on inappropriate prescribing to children and safety issues in children's medicine use. Monitoring changing patterns of use over time is important for the evaluation of effective therapies in children and any potential harmful consequences of prescribing.

Characteristics of a stratified random sample of New Zealand general practices.

INTRODUCTION Practice size and location may affect the quality and safety of health care. Little is known about contemporary New Zealand general practice characteristics in terms of staffing, ownership and services. AIM To describe and compare the characteristics of small, medium and large general practices in rural and urban New Zealand. METHODS Seventy-two general practices were randomly selected from the 2014 Primary Health Organisation database and invited to participate in a records review study. Forty-five recruited practices located throughout New Zealand provided data on staff, health-care services and practice ownership. Chi-square and other non-parametric statistical analyses were used to compare practices. RESULTS The 45 study practices constituted 4.6% of New Zealand practices. Rural practices were located further from the nearest regional base hospital (rural median 65.0 km, urban 7.5 km (P < 0.001)), nearest local hospital (rural 25.7 km, urban 7.0 km (P = 0.002)) and nearest neighbouring general practitioner (GP) (rural 16.0 km, urban 1.0 km (P = 0.007)). In large practices, there were more enrolled patients per GP FTE than both medium-sized and small practices (mean 1827 compared to 1457 and 1120 respectively, P = 0.019). Nurses in large practices were more likely to insert intravenous lines (P = 0.026) and take blood (P = 0.049). There were no significant differences in practice ownership arrangements according to practice size or rurality. CONCLUSION Study practices were relatively homogenous. Unsurprisingly, rural practices were further away from hospitals. Larger practices had higher patient-to-doctor ratios and increased nursing scope. The study sample is small; findings need to be confirmed by specifically powered research.

Atrial fibrillation in New Zealand primary care: Prevalence, risk factors for stroke and the management of thromboembolic risk.

Background Atrial fibrillation is a major risk factor for stroke and heart disease but there is limited information on its prevalence in New Zealand primary care or the treatment provided to manage thromboembolic risk. Our aim was to estimate the prevalence of atrial fibrillation, assess patient risk for thromboembolism and evaluate the appropriateness of risk reduction using antiplatelet and oral anticoagulation therapy. Design A retrospective cohort study utilising electronic medical records for 739,000 patients registered with 170 general practices in 2014. Methods Patient diagnoses and prescriptions from 2010-2014 were analysed to identify patients with atrial fibrillation in 2014 and co-morbidities included in the CHA2DS2-VASc algorithm. Adjusted prevalence of atrial fibrillation by patient demographic group and the proportion of patients following recommended antithrombotic therapy were calculated. Results 12,712 patients were identified with AF (1.72%, 95% confidence interval 1.69%-1.75%). Prevalence was significantly higher for Maori (odds ratio 1.91, 95% confidence interval 1.80-2.03) than Europeans after adjusting for age, sex, deprivation and clinical risk factors. Stroke risk for Maori and Pacific Island patients was higher than for Europeans across all age groups. Of the 10,406 patients (81.9%) at high risk for thromboembolism, 60.5% were using anticoagulants, 24.1% aspirin monotherapy and 15.4% neither anticoagulants nor aspirin. Oral anticoagulants were used by 31.5% of patients at low risk (CHA2DS2-VASc <2). Conclusions Oral anticoagulants are under-utilised in the management of thromboembolic risk in high risk patients with atrial fibrillation. Better promotion of guideline recommendations for the treatment of patients with atrial fibrillation may be required to improve clinician and patient decision-making.

Appropriateness of general practitioner imaging requests for transient ischaemic attack patients: secondary analysis of a cluster randomised controlled trial.

AIMS Many transient ischaemic attack (TIA) patients receive initial assessments by general practitioners (GPs). In a randomised controlled trial (RCT) we showed that BPAC Inc. TIA/stroke electronic decision support (EDS) for GPs improves patient outcomes and guideline adherence. This secondary analysis assesses the impact of trial associated enhanced GP access to radiological investigation. METHODS Post-hoc analysis of a multi-centre, single blind, parallel group, cluster RCT comparing TIA/stroke EDS guided GP management with usual care to assess whether imaging requests and their appropriateness differed between study groups. RESULTS GPs requested 15/291 (5.2%) carotid ultrasounds and 19/291 (6.5%) computed tomography (CT) head scans. Scans were obtained more frequently in the intervention group (ultrasound cluster adjusted OR (95% CI) 1.41 (0.44 to 4.49), P = 0.56 and CT 13.8 (1.7 to 110.7), P < 0.001). All CTs were clinically appropriate. More ultrasounds were appropriate in the EDS group (cluster adjusted OR (95% CI) of 8.4 (0.39 to 92.3), P = 0.18). Overall investigation costs did not differ between groups (P = 0.83). Some apparent avoidable imaging duplication occurred where patients were subsequently assessed by secondary services. CONCLUSION In the setting of a RCT assessing GP electronic decision support, frequency of GP initiated imaging requests was low and largely appropriate especially in the setting of EDS use. Thus enhanced GP imaging access as part of the EDS tool did not result in inappropriate or excessive GP imaging requests. However, some duplication occurred and practitioners need to ensure that test referrals and results are adequately communicated between sectors.

A Pharmacoepidemiology Database System for Monitoring Risk Due to the Use of Medicines by New Zealand Primary Care Patients.

INTRODUCTION: The use of large record-linked healthcare databases for drug safety research and surveillance is now accepted practice. New Zealand's standardized national healthcare datasets provide the potential to automate the conduct of pharmacoepidemiological studies to provide rapid validation of medicine safety signals. OBJECTIVES: Our objectives were to describe the methodology undertaken by a semi-automated computer system developed to rapidly assess risk due to drug exposure in New Zealand's population of primary care patients and to compare results from three studies with previously published findings. METHODS: Data from three national databases were linked at the patient level in the automated studies. A retrospective nested case-control design was used to evaluate risk for upper gastrointestinal bleeding (UGIB), acute kidney failure (AKF), and serious arrhythmia associated with individual medicines, therapeutic classes of medicines, and concurrent use of medicines from multiple therapeutic classes. RESULTS: The patient cohort available for each study included 5,194,256 patients registered between 2007 and 2014, with a total of 34,630,673 patient-years at risk. An increased risk for UGIB was associated with non-steroidal anti-inflammatory drugs (NSAIDs) (adjusted odds ratio [AOR] 4.16, 95% confidence interval [CI] 3.90-4.43, p < 0.001) and selective serotonin reuptake inhibitors (AOR 1.39, 95% CI 1.20-1.62, p < 0.001); an increased risk for AKF was associated with NSAIDs (AOR 1.78, 95% CI 1.73-1.83, p < 0.001) and proton pump inhibitors (AOR 1.78, 95% CI 1.72-1.83, p < 0.001); and an increased risk for serious arrhythmia was associated with fluoroquinolones (AOR 1.38, 95% CI 1.26-151, p < 0.001) and penicillins (AOR 1.69, 95% CI 1.61-1.77, p < 0.001). CONCLUSIONS: Automated case-control studies using New Zealand's healthcare datasets can replicate associations of risk with drug exposure consistent with previous findings. Their speed of conduct enables systematic monitoring of risk for adverse events associated with a wide range of medicines.

Epidemiology of Patient Harms in New Zealand: Protocol of a General Practice Records Review Study.

BACKGROUND: Knowing where and why harm occurs in general practice will assist patients, doctors, and others in making informed decisions about the risks and benefits of treatment options. Research to date has been unable to verify the safety of primary health care and epidemiological research about patient harms in general practice is now a top priority for advancing health systems safety. OBJECTIVE: We aim to study the incidence, distribution, severity, and preventability of the harms patients experience due to their health care, from the whole-of-health-system lens afforded by electronic general practice patient records. METHODS: "Harm" is defined as disease, injury, disability, suffering, and death, arising from the health system. The study design is a stratified, 2-level cluster, retrospective records review study. Both general practices and patients will be randomly selected so that the study's results will apply nationally, after weighting. Stratification by practice size and rurality will allow comparisons between 6 study groups (large, medium-sized, small; urban and rural practices). Records of equal numbers of patients from each study group will be included in the study because there may be systematic differences in patient harms in different types of practices. Eight general practitioner investigators will review 3 years of electronic general practice health records (consultation notes, prescriptions, investigations, referrals, and summaries of hospital care) from 9000 patients registered in 60 general practices. Double-blinded reviews will check the concordance of reviewers' assessments. Study data will comprise demographic data of all 9000 patients and reviewers' assessments of whether patients experienced harm arising from health care. Where patient harm is identified, their types, preventability, severity, and outcomes will be coded using the Medical Dictionary for Regulatory Activities (MedDRA) 18.0. RESULTS: We have recruited practices and collected electronic records from 9078 patients. Reviews of these records are under way. The study is expected to be completed in August 2017. CONCLUSIONS: The design of this complex study is presented with discussion on data collection methods, sampling weights, power analysis, and statistical approach. This study will show the epidemiology of patient harms recorded in general practice records for all of New Zealand and will show whether this epidemiology differs by rural location and clinic size.