Research

Percutaneous coronary intervention with stent implantation (PCI‐S) has revolutionised the management of patients with coronary artery disease at high risk of myocardial infarction and stroke.1 Dual antiplatelet therapy (aspirin with clopidogrel, prasugrel or ticagrelor) is superior to aspirin alone for preventing atherothrombotic events, including stent thrombosis, in patients undergoing PCI‐S,2 and is recommended by Australian guidelines.3 We analysed de‐identified, linked Pharmaceutical Benefits Scheme (PBS) and Medicare Benefits Schedule (MBS) data for a 10% random sample of Medicare beneficiaries provided by the Australian Department of Health, to quantify rates of antiplatelet drug dispensing within 30 days of PCI‐S. We included all patients with MBS claims for PCI‐S (items 38306, 38312, 38318) between 1 January 2013 and 30 September 2014. MBS data on PCI‐S procedures are available only for private patients, who account for about 45% of PCI‐S procedures in Australia.4 The medicines of interest for our analysis were clopidogrel and clopidogrel/aspirin (Anatomical Therapeutic Chemical [ATC] codes B01AC04 and B01AC30), ticagrelor (ATC code B01AC24), and prasugrel (ATC code B01AC22). Aspirin alone was not examined because over‐the‐counter use is not captured in PBS claims data. We assessed the association of several factors with antiplatelet medication dispensing within 30 days of PCI‐S, expressed as odds ratios, by logistic regression modelling. The New South Wales Population and Health Services Research Ethics Committee approved the study (Cancer Institute NSW reference, 2013/11/494). Of 2869 patients who underwent PCI‐S during the study period, 2592 (90%) were dispensed antiplatelet drugs within 30 days of the procedure. Dispensing was more frequent for concessional PBS beneficiaries, patients who had not undergone PCI‐S in the preceding year, patients not dispensed antiplatelet drugs during the preceding six months, and patients dispensed proton pump inhibitors within 30 days of the procedure. Antiplatelet therapy was also more frequent among patients from Victoria or Tasmania, Queensland, and Western Australia than for those from NSW or the Australian Capital Territory (Box). Our findings indicate that 10% of patients undergoing PCI‐S did not receive guideline‐recommended dual antiplatelet therapy within 30 days of their procedure. Cost may have been a barrier, as antiplatelet therapy was less frequent among general than concessional PBS beneficiaries; the maximum out‐of‐pocket cost for any single PBS item in 2013 was $5.90 for concessional beneficiaries, but $36.10 for general beneficiaries, and general beneficiaries may have already experienced significant out‐of‐pocket costs for both health insurance and their procedure. In most states, the Public Hospitals Pharmaceutical Reform Agreement6 ensures that PBS‐subsidised medications can be dispensed to patients when they are discharged from hospital. NSW and the ACT, however, do not participate in this agreement; patients are discharged from public hospitals with unsubsidised medicines sufficient for only 2–7 days, after which they must visit a community doctor for prescribing of PBS‐subsidised medications. This inconvenience may contribute to the lower 30‐day dispensing rate in these jurisdictions. We were unable to evaluate the long term clinical effect of antiplatelet therapy as the analysed datasets do not include information about hospital admissions. The number of PCI‐S procedures in Australia increased from 24 500 MBS claims in 2013 to 29 000 in 2018 (http://medicarestatistics.humanservices.gov.au/statistics/mbs_item.jsp), and the number of patients at risk of early stent thrombosis may also have grown. Why some patients undergoing PCI‐S are not receiving dual antiplatelet therapy directly after their procedure should be further investigated. Box – Characteristics of patients undergoing percutaneous coronary intervention with stent implantation (PCI‐S) in Australia, and their association with dual antiplatelet therapy within 30 days of PCI‐S Number of patients Odds ratio (95% confidence interval) Underwent PCI‐S Antiplatelet therapy within 30 days Univariate models Multivariate model Total number of patients undergoing PCI‐S 2869 2592 (90%) Age (years) 18–54 351 (12%) 307 (87%) 1 1 55–64 711 (25%) 640 (90%) 1.29 (0.87–1.93) 1.26 (0.83–1.91) 65–74 965 (34%) 879 (91%) 1.47 (0.99–2.16) 1.17 (0.76–1.81) 75–84 660 (23%) 605 (92%) 1.58 (1.04–2.40) 1.09 (0.66–1.81) 85 or more 182 (6%) 161 (88%) 1.10 (0.63–1.91) 0.83 (0.66–1.60) Sex Women 670 (23%) 604 (90%) 1 1 Men 2199 (77%) 1988 (90%) 0.97 (0.73–1.30) 0.86 (0.63–1.18) State where PCI‐S was undertaken New South Wales/Australian Capital Territory 1121 (39%) 986 (88%) 1 1 Victoria/Tasmania 752 (26%) 694 (92%) 1.64 (1.19–2.26) 1.56 (1.12–2.17) South Australia/Northern Territory 147 (5%) 129 (88%) 0.98 (0.58–1.66) 0.94 (0.55–1.60) Queensland 549 (19%) 504 (92%) 1.53 (1.08–2.19) 1.47 (1.02–2.13) Western Australia 300 (10%) 279 (93%) 1.82 (1.13–2.94) 2.14 (1.28–3.59) PBS patient category General 1453 (51%) 1293 (89%) 1 1 Concessional 1404 (49%) 1299 (93%) 1.53 (1.18–1.98) 1.63 (1.18–2.26) Previous PCI‐S Preceding 12 months 234 (8%) 199 (85%) 1 1 None 2635 (92%) 2393 (91%) 1.74 (1.19–2.55) 1.41 (0.93–2.13) Previous antiplatelet therapy Preceding 6 months 1135 (40%) 995 (88%) 1 1 None 1734 (60%) 1597 (92%) 1.64 (1.28–2.10) 1.96 (1.45–2.64) Anticoagulant therapy within 30 days of PCI‐S No 84 (3%) 77 (92%) 1 1 Yes 2785 (97%) 2515 (90%) 1.18 (0.54–2.59) 1.04 (0.47–2.33) Proton pump inhibitor therapy within 30 days of PCI‐S No 1002 (35%) 931 (93%) 1 1 Yes 1867 (65%) 1661 (89%) 1.63 (1.23–2.16) 1.42 (1.05–1.92) Comorbid conditions (six months before PCI‐S) None 196 (7%) 169 (86%) 1 1 1 180 (6%) 165 (92%) 1.76 (0.90–3.42) 1.47 (0.72–3.01) 2 259 (9%) 234 (90%) 1.50 (0.84–2.67) 1.34 (0.71–2.56) 3 389 (14%) 356 (92%) 1.72 (1.00–2.96) 1.54 (0.84–2.82) 4 452 (16%) 395 (87%) 1.11 (0.68–1.81) 1.01 (0.57–1.79) 5 or more 1393 (49%) 1273 (91%) 1.70 (1.08–2.65) 1.56 (0.88–2.75) PBS = Pharmaceutical Benefits Scheme. *Patients were classified as concessional beneficiaries if all PBS dispensing was concessional during year preceding and the three months following the PCI‐S procedure. †Based on RxRisk comorbidity indices.5

Benjumin Hsu · Michael O Falster · Andrea L Schaffer · Sallie Pearson · Louisa Jorm · David B Brieger

Objective: To examine the prevalence of psychotropic medicine dispensing before and after older people enter residential care. Design: Retrospective national cohort study; analysis of Registry of Senior Australians (ROSA) data. Setting, participants: All concession card‐holding residents of government‐subsidised residential aged care facilities in Australia who entered residential care for at least three months between 1 April 2008 and 30 June 2015. Main outcome measures: Proportions of residents dispensed antipsychotic, benzodiazepine, or antidepressant medicines during the year preceding and the year after commencing residential care, by quarter. Results: Of 322 120 included aged care residents, 68 483 received at least one antipsychotic (21.3%; 95% CI, 21.1–21.4%), 98 315 at least one benzodiazepine (30.5%; 95% CI, 30.4–30.7%), and 122 224 residents at least one antidepressant (37.9%; 95% CI, 37.8–38.1%) during their first three months of residential care; 31 326 of those dispensed antipsychotics (45.7%), 38 529 of those dispensed benzodiazepines (39.2%), and 25 259 residents dispensed antidepressants (19.8%) had not received them in the year preceding their entry into care. During the first three months of residential care, the prevalence of antipsychotic (prevalence ratio [PR], 3.37; 95% CI, 3.31–3.43) and antidepressant dispensing (PR, 1.05; 95% CI, 1.04–1.07) were each higher for residents with than for those without dementia; benzodiazepine dispensing was similar for both groups (PR, 1.01; 95% CI, 0.99–1.02). Conclusions: Dispensing of psychotropic medicines to older Australians is high before they enter residential care but increases markedly soon after entry into care. Non‐pharmacological behavioural management strategies are important for limiting the prescribing of psychotropic medicines for older people in the community or in residential care.

Stephanie L Harrison · Janet K Sluggett · Catherine Lang · Craig Whitehead · Maria Crotty · Megan Corlis · Steven L Wesselingh · Maria C Inacio

Objectives: To assess the risks of stroke and cardiovascular mortality for Aboriginal and non‐Aboriginal Australians with atrial fibrillation. Design: Retrospective data linkage cohort study. Setting, participants: All people aged 20–84 years hospitalised with atrial fibrillation in Western Australia during 2000–2012. Main outcome measures: Stroke incidence rates and mortality after hospitalisation for atrial fibrillation, and 10‐year risks of stroke and of cardiovascular and all‐cause mortality. Results: Among 55 482 index admissions with atrial fibrillation, 7.7% of 20–59‐year‐old patients and 1.3% of 60–84‐year‐old patients were Aboriginal Australians. A larger proportion of Aboriginal patients aged 20–59 years had CHA2DS2‐VASc scores of 2 or more (59.8% v 21.8%). In 20–59‐year‐old Aboriginal patients, the incidence during follow‐up (maximum, 10 years; median, 7.1 years) of stroke (incidence rate ratio [IRR], 3.2; 95% CI, 2.5–4.1) and fatal stroke (IRR, 5.7; 95% CI, 3.9–8.9) were markedly higher than for non‐Aboriginal patients. Stroke incidence was higher for 60–84‐year‐old patients, but the difference between Aboriginal and non‐Aboriginal patients was smaller (IRR, 1.6; 95% CI, 1.3–2.0). Cardiovascular mortality during follow‐up was also higher for 20–59‐year‐old Aboriginal patients (IRR, 4.4; 95% CI, 4.3–5.9). The hazards of stroke (adjusted HR [aHR], 1.67; 95% CI, 1.22–2.28) and cardiovascular mortality (aHR, 1.47; 95% CI, 1.18–1.83) in younger Aboriginal patients remained significantly higher after multivariable adjustment; age/sex, principal diagnosis of atrial fibrillation, and CHA2DS2‐VASc score were the most influential factors. Conclusion: Stroke risk and cardiovascular mortality are markedly higher for Aboriginal than non‐Aboriginal patients with atrial fibrillation, particularly for patients under 60. Strategies for providing evidence‐based therapies and cardiovascular prevention to Aboriginal people with atrial fibrillation must be improved.

Lee Nedkoff · Erin A Kelty · Joseph Hung · Sandra C Thompson · Judith M Katzenellenbogen

Colorectal cancer is an important cause of morbidity and mortality in Australia.1 The National Bowel Cancer Screening Program (NBCSP) aims to detect the disease early by offering faecal occult blood testing (faecal immunochemical test, FIT) to people aged 50–74 years.2 The expansion of the NBCSP has been paralleled by increased numbers of FITs outside the program (community‐initiated FITs) for a number of reasons, including the presence of symptoms. We investigated whether colonoscopy services should provide endoscopies to patients with positive FIT results with the same priority, regardless of whether the test was instigated by the NBCSP, by analysing data from the Newcastle Direct Access Colonoscopy Service (DACS) for the period 2014–18. The DACS manages all patients in the same manner: a positive FIT result leads to assessment for colonoscopy.3,4 Ethics approval was granted by the Hunter New England Human Research Ethics Committee (reference, AU201608‐01). All data were recorded prospectively. Findings were categorised according to surveillance categories endorsed by the Gastroenterological Society of Australia and the Colorectal Surgical Society of Australia and New Zealand.5 Data accuracy was confirmed by reviewing the primary sources for 10% of patients. We identified 2693 patients referred for screening colonoscopy between 1 July 2014 and 30 June 2018; 1439 (53%) had had community‐initiated FITs (Box 1). After excluding 318 patients who did not attend or were lost to follow‐up (community‐initiated, 200; NBCSP, 118) and ten patients with poor bowel preparation and no follow‐up colonoscopy during the study period, 2365 complete screening colonoscopy outcomes were analysed: 1233 following community‐initiated and 1132 following NBCSP testing. With these sample sizes, the study had 80% power to detect differences in colonic neoplasia rate ranging from 16 percentage points (assumed prevalence, 50%) to two percentage points (assumed prevalence, 3%). Z‐tests were used to calculate P values, and Wald tests (two‐tailed) for calculating confidence intervals (CIs) for the differences between the two groups. Differences between the two groups in the proportion of patients with each specific finding are presented with 99% asymptotic CIs to control for multiple testing. Colonoscopy quality was high: the completion rate (defined as either caecal intubation, reaching an ileocolic anastomosis, or reaching an obstructing mass lesion) was 97.1% (community‐initiated, 1193 of 1233, 96.8%; NBCSP, 1104 of 1132, 97.5%), and the adenoma detection rate was 49%, exceeding international benchmarks for either symptomatic or screening patients (for screening: at least 25% in men and 15% in women;6 for populations enriched with patients with positive FIT results: 35%7). The rate of colorectal neoplasia (malignant or pre‐malignant) was similar in the two groups. Importantly, the difference in the rates of adenocarcinoma was not statistically significant (community‐initiated, 4.0%; NBCSP, 2.7%; difference, 1.3 percentage points [99% CI, –0.6 to 3.3 percentage points]; P = 0.09). The only statistically significant difference by type was that the incidence of high risk adenoma was slightly higher in the NBCSP group (22.9% v 17.2%; difference, 5.7 percentage points [99% CI, 1.4–10 percentage points]; P < 0.001) (Box 2). We found that the incidence and detection rates of colorectal neoplasia in people aged 50–74 years were similar for people with positive results for NBCSP or community‐initiated FITs. The large population in our study means that it provides colonoscopy providers strong evidence that evaluation should be performed equally promptly for patients with positive results from NBSCP and community‐initiated FITs. Box 1 – Demographic characteristics of the 2693 patients with positive faecal immunochemical test results and referred to the Newcastle Direct Access Colonoscopy Service for colonoscopy, 2014–18 Faecal immunochemical test Total Community‐initiated NBCSP Number of patients 1439 1254 2693 Sex Women 675 559 1234 Men 764 695 1459 Age (years), mean (SD) 62.9 (6.8) 63.2 (7.3) 63.1 (7.0) Numbers of patients 50–54 years 213 147 360 55–59 years 280 271 551 60–64 years 312 212 524 65–69 years 330 288 618 70–74 years 304 336 640 NBCSP = National Bowel Cancer Screening Program; SD = standard deviation. Box 2 – Differences in colonoscopy outcomes for people who had community‐initiated (1233 patients) or NBCSP (1132 patients) faecal immunochemical tests CI = confidence interval; NBCSP = National Bowel Cancer Screening Program. *Large sessile polyps (> 2 cm) or malignant polyps. † Between values for community‐initiated and NBCSP groups.

Simon Whitcher · Monique Magnusson · Jon Gani · Christopher Oldmeadow · Peter G Pockney

Patients with ruptured HCC should be treated with the aim of long term survival

Natassia P Tan · Ammar Majeed · Stuart K Roberts · Paul J Gow · Penny Hey · Xianjun Mah · Mark Goodwin · Siddharth Sood · John Lubel · Amanda Nicoll · Anouk Dev · Sally J Bell · William W Kemp

The impact of discharge destination on outcomes after treatment for orthopaedic trauma requires further investigation

Lara A Kimmel · Pamela M Simpson · Anne E Holland · Elton R Edwards · Peter A Cameron · Richard S Steiger · Richard S Page · Raphael Hau · Andrew Bucknill · Jessica Kasza · Belinda J Gabbe

The causes of childhood cancers must be understood before interventions to reduce their incidence can be developed

Danny R Youlden · Peter D Baade · Adèle C Green · Patricia C Valery · Andrew S Moore · Joanne F Aitken

Self-reported wheat sensitivity was reported by 14% of respondents in both 2015 and 2018

Michael DE Potter · Michael P Jones · Marjorie M Walker · Natasha A Koloski · Simon Keely · Gerald Holtmann · Nicholas J Talley AC

Inaccurate recording of Indigenous status in administrative datasets can influence health service decision making

Mary O'Loughlin · Linton Harriss · Jane Mills · Fintan Thompson · Robyn McDermott

SmartStartAllergy faccilitates monitoring of infant feeding practices in primary care and parent-reported reactions to food

Michael O'Sullivan · Sandra Vale · Richard KS Loh · Jessica Metcalfe · Karin Orlemann · Sandra Salter · Ian Peters · Alan Leeb

Cancer overdiagnosis is a substantial problem that urgently requires changes in public health policy

Paul P Glasziou · Mark A Jones · Thanya Pathirana · Alexandra L Barratt · Katy JL Bell

Blood lead levels in the pre-school children in our sample were lower than in previous surveys

Christos Symeonides · Peter Vuillermin · Peter D Sly · Fiona Collier · Victoria Lynch · Sandra Falconer · Angela Pezic · Nicole Wardrop · Terence Dwyer · Sarath Ranganathan · Anne‐Louise B Ponsonby

Survivors of childhood cancer remain at increased risk of a second primary cancer well into adulthood

Danny R Youlden · Peter D Baade · Adèle C Green · Patricia C Valery · Andrew S Moore · Joanne F Aitken

Rates of non-reconstructive, non-reparative arthroscopic procedures in people over 50 years have declined over the past 10 years

So Mang (Simon) Lee · Wasim Awal · Christopher Vertullo

Essential oil exposures are frequent in Australia, and more than half involve children

Kristenbella AYR Lee · Joanna E Harnett · Rose Cairns

Introducing the floor price was followed by a significant reduction in ICU admissions associated with acute alcohol misuse

Paul J Secombe · Penny Stewart · Alex Brown · Michael J Bailey · David Pilcher

The clinical significance of asymptomatic infection is uncertain, and routine testing is not recommended

James D Stewart · Brooke Webb · Michelle Francis · Maryza Graham · Tony M Korman

Mental disorders in children known to child protection services during early childhood

Melissa J. Green · Gabrielle Hindmarsh · Maina Kariuki · Kristin R. Laurens · Amanda L Neil · Ilan Katz · Marilyn Chilvers · Felicity Harris · Vaughan J Carr

Changes in the modes of twin birth in Victoria, 1983–2015

Yizhen (Amy) Liu · Mary‐Ann Davey · Rilka Lee · Kirsten R Palmer · Euan M Wallace

The decline in codeine-related presentations was not associated with a rise in alternative opioid-related presentations

Keith Harris · Andrew Jiang · Robert Knoeckel · Katherine Z Isoardi

Glucose and HbA1c screening alone does not increase detection of previously unidentified diabetes in patients admitted from EDs

N Wah Cheung · Lesley V Campbell · Gregory R Fulcher · Patrick McElduff · Barbara Depczynski · Shamasunder Acharya · John Carter · Bernard Champion · Roger Chen · David Chipps · Jeff Flack · Jen Kinsella · Margaret Layton · Mark McLean · Robert G Moses · Kris Park · Ann M Poynten · Carol Pollock · Debbie Scadden · Katherine T Tonks · Mary Webber · Chris White · Vincent Wong · Sandy Middleton

The current method for calculating lifetime risks overestimates these risks, especially for men

Anthea C Bach · Kelvin SE Lo · Thanya Pathirana · Paul P Glasziou · Alexandra L Barratt · Mark A Jones · Katy JL Bell

Universal tumour testing strategies for guiding germline genetic testing are likely to be cost-effective compared with no testing

Yoon‐Jung Kang · James Killen · Michael Caruana · Kate Simms · Natalie Taylor · Ian M Frayling · Tristan Snowsill · Nicola Huxley · Veerle MH Coupe · Suzanne Hughes · Victoria Freeman · Alex Boussioutas · Alison H Trainer · Robyn L Ward · Gillian Mitchell · Finlay A Macrae · Karen Canfell

Breast cancer detection, recall for assessment, and screen reading time were each higher for tomosynthesis than standard mammography

Nehmat Houssami · Darren Lockie · Michelle Clemson · Vicki Pridmore · David Taylor · Georgina Marr · Jill Evans · Petra Macaskill

More systematic data collection could assist clinicians and patients when considering overseas travel for organ transplantation

Georgia Smith · Diba Gujari · Oscar Russell · Lyle Palmer · Maeghan Toews · Germaine Wong · Wai Lim · Stephen McDonald · Phillip Clayton · Dominique Martin · Patrick T Coates