Effect of Low-Dose Aspirin on the Course of Age-Related Macular Degeneration: A Secondary Analysis of the ASPREE Randomized Clinical Trial.

Importance: Age-related macular degeneration (AMD) is the leading cause of irreversible vision loss in old age. There is no proven intervention to prevent AMD and, apart from lifestyle, nutritional, and supplement advice, there is no intervention to delay its progression. Objective: To determine the impact of long-term low-dose aspirin on the incidence and progression of AMD. Design, Setting and Participants: The Aspirin in Reducing Events in the Elderly-AMD (ASPREE-AMD) study was an Australian-based substudy of the ASPREE trial, a multicenter, international, randomized, double-masked, placebo-clinical trial investigating the efficacy of low-dose aspirin in prolonging disability-free survival among older individuals. Retinal photography was conducted at baseline from March 2010 to January 2015, then 3 and 5 years after randomization. AMD status was determined using color retinal images and treatment records. Australian participants in ASPREE aged 70 years and older without dementia, independence-limiting physical disability, cardiovascular disease, or chronic illness limiting 5-year survival and with gradable retinal images at baseline were included. Data were analyzed from December 2022 to December 2023. Interventions: Aspirin (100 mg daily, enteric coated) or placebo. Main Outcomes and Measures: Incidence of AMD and progression from early/intermediate to late AMD. Outcomes were analyzed by modified intention-to-treat analysis. Results: A total of 4993 participants were enrolled in this substudy. Baseline characteristics were similar between groups. At the time of sponsor-determined trial termination, retinal follow-up data were available for 3208 participants, 3171 of whom were analyzed for AMD incidence and progression, with a median (IQR) age of 73.5 (71.5-76.4) years and even sex distribution (1619 [51%] female). Median (IQR) follow-up time was 3.1 (3.0-3.5) years. Cumulative AMD incidence was 195 of 1004 (19.4%) in the aspirin group and 187 of 979 (19.1%) in the placebo group (relative risk [RR], 1.02; 95% CI, 0.85-1.22; P = .86). Cumulative progression from early/intermediate AMD to late AMD was observed in 14 of 615 (2.3%) participants in the aspirin group and 18 of 573 (3.1%) in the placebo group (RR, 0.72; 95% CI, 0.36-1.44; P = .36). Conclusions and Relevance: In this trial, low-dose aspirin administered for 3 years did not affect the incidence of AMD. The evidence was weaker for progression of AMD due to low number of progressed cases. Overall, these results do not support suggestion that low-dose daily aspirin prevents the development or progression of AMD. Trial Registration: anzctr.org Identifier: ACTRN12613000755730.

Symptoms of depression and risk of emergency department visits among people aged 70 years and over.

BACKGROUND: Older people experiencing depression and anxiety have higher rates of health service utilisation than others, but little is known about whether these influence their seeking of emergency care. The aim was to examine the associations between symptoms of depression and the use of emergency health care, in an Australian context, among a population of people aged 70 years and over initially free of cardiovascular disease, dementia or major physical disability. METHODS: We undertook secondary analyses of data from a large cohort of community-dwelling Australians aged [Formula: see text]70 years. Multivariable logistic regression was used to compare the association of symptoms of depression (measured using the Center for Epidemiological Studies Depression Scale 10 question version, CESD at baseline) with subsequent episodes of emergency care, adjusting for physical and social factors of clinical interest. Marginal adjusted odds ratios were calculated from the logistic regression. RESULTS: Data were available for 10,837 Australian participants aged at least 70 years. In a follow-up assessment three years after the baseline assessment, 17.6% of people self-reported an episode of emergency care (attended an ED of called an emergency ambulance) in the last 12 months. Use of emergency healthcare was similar for men and women (17.8% vs. 17.4% p = 0.61). A score above the cut-off on the CESD at baseline was associated with greater use of emergency health care (OR = 1.35, 95% CI 1.11,1.64). When modelled separately, there was a greater association between a score above the cut-off on the CESD and emergency healthcare for women compared with men. CONCLUSIONS: This study is unique in demonstrating how depressive symptoms among healthy older persons are associated with subsequent increased use of emergency healthcare. Improved understanding and monitoring of mental health in primary care is essential to undertake effective healthcare planning including prevention of needing emergency care.

Infective complications in cancer patients treated with subcutaneous versus intravenous trastuzumab and rituximab: An individual patient data meta-analysis.

BACKGROUND: Investigation of infection risk with subcutaneous versus intravenous trastuzumab and rituximab administration in an individual patient data (IPD) and published data meta-analysis of randomised controlled trials (RCTs). METHODS: Databases were searched to September 2021. Primary outcomes were serious and high-grade infection. Relative-risk (RR) and 95% confidence intervals (95%CI) were calculated using random-effects models. RESULTS: IPD meta-analysis (6 RCTs, 2971 participants, 2320 infections) demonstrated higher infection incidence with subcutaneous versus intravenous administration, without reaching statistical significance (serious: 12.2% versus 9.3%, RR 1.28, 95%CI 0.93to1.77, P = 0.13; high-grade: 12.2% versus 9.9%, RR 1.32, 95%CI 0.98to1.77, P = 0.07). With exclusion of an outlying study in post-hoc analysis, increased risks were statistically significant (serious: 13.1% versus 8.4%, RR 1.53, 95%CI 1.14to2.06, P = 0.01; high-grade: 13.2% versus 9.3%, RR 1.56, 95%CI 1.16to2.11, P < 0.01). Published data meta-analysis (8 RCTs, 3745 participants, 648 infections) demonstrated higher incidence of serious (HR 1.31, 95%CI 1.02to1.68, P = 0.04) and high-grade (HR 1.52, 95%CI 1.17to1.98, P < 0.01) infection with subcutaneous versus intravenous administration. CONCLUSIONS: Results suggest increased infection risk with subcutaneous versus intravenous administration, although IPD findings are sensitive to exclusion of one trial with inconsistent results and identified risk-of-bias. Ongoing trials may confirm findings. Clinical surveillance should be considered when switching to subcutaneous administration. PROSPERO registration CRD42020221866/CRD42020125376.

Examining evidence of time-dependent treatment effects: an illustration using regression methods.

BACKGROUND: For the design and analysis of clinical trials with time-to-event outcomes, the Cox proportional hazards model and the logrank test have been the cornerstone methods for many decades. Increasingly, the key assumption of proportionality-or time-fixed effects-that underpins these methods has been called into question. The availability of novel therapies with new mechanisms of action and clinical trials of longer duration mean that non-proportional hazards are now more frequently encountered. METHODS: We compared several regression-based methods to model time-dependent treatment effects. For illustration purposes, we used selected endpoints from a large, community-based clinical trial of low dose daily aspirin in older persons. Relative and absolute estimands were defined, and analyses were conducted in all participants. Additional exploratory analyses were undertaken by selected subgroups of interest using interaction terms in the regression models. DISCUSSION: In the trial with median 4.7 years follow-up, we found evidence for non-proportionality and a time-dependent treatment effect of aspirin on cancer mortality not previously reported in trial findings. We also found some evidence of time-dependence to an aspirin by age interaction for major adverse cardiovascular events. For other endpoints, time-fixed treatment effect estimates were confirmed as appropriate. CONCLUSIONS: The consideration of treatment effects using both absolute and relative estimands enhanced clinical insights into potential dynamic treatment effects. We recommend these analytical approaches as an adjunct to primary analyses to fully explore findings from clinical trials.

Impact of a non-constant baseline hazard on detection of time-dependent treatment effects: a simulation study.

BACKGROUND: Non-proportional hazards are common with time-to-event data but the majority of randomised clinical trials (RCTs) are designed and analysed using approaches which assume the treatment effect follows proportional hazards (PH). Recent advances in oncology treatments have identified two forms of non-PH of particular importance - a time lag until treatment becomes effective, and an early effect of treatment that ceases after a period of time. In sample size calculations for treatment effects on time-to-event outcomes where information is based on the number of events rather than the number of participants, there is crucial importance in correct specification of the baseline hazard rate amongst other considerations. Under PH, the shape of the baseline hazard has no effect on the resultant power and magnitude of treatment effects using standard analytical approaches. However, in a non-PH context the appropriateness of analytical approaches can depend on the shape of the underlying hazard. METHODS: A simulation study was undertaken to assess the impact of clinically plausible non-constant baseline hazard rates on the power, magnitude and coverage of commonly utilized regression-based measures of treatment effect and tests of survival curve difference for these two forms of non-PH used in RCTs with time-to-event outcomes. RESULTS: In the presence of even mild departures from PH, the power, average treatment effect size and coverage were adversely affected. Depending on the nature of the non-proportionality, non-constant event rates could further exacerbate or somewhat ameliorate the losses in power, treatment effect magnitude and coverage observed. No single summary measure of treatment effect was able to adequately describe the full extent of a potentially time-limited treatment benefit whilst maintaining power at nominal levels. CONCLUSIONS: Our results show the increased importance of considering plausible potentially non-constant event rates when non-proportionality of treatment effects could be anticipated. In planning clinical trials with the potential for non-PH, even modest departures from an assumed constant baseline hazard could appreciably impact the power to detect treatment effects depending on the nature of the non-PH. Comprehensive analysis plans may be required to accommodate the description of time-dependent treatment effects.

Odds of culpability associated with use of impairing drugs in injured drivers in Victoria, Australia.

Culpability analysis was conducted on 5000 drivers injured as a result of a vehicular collision and in whom comprehensive toxicology testing in blood was conducted. The sample included 1000 drivers for each of 5 years from approximately 5000-6000 drivers injured and taken to hospital in the State of Victoria. Logistic regression was used to investigate differences in the odds of culpability associated with alcohol and drug use and other selected crash attributes using the drug-free driver as the reference group. Adjusted odds ratios were obtained from multivariable logistic regression models in which other potentially explanatory driver and crash attributes were included. Drivers with alcohol present showed large increases in the odds of culpability similar to that seen in other studies investigating associations between blood alcohol concentration and crash risk. Methylamphetamine also showed a large increase in the odds of culpability (OR 19) compared to the reference group at both below and above 0.1 mg/L, whereas those drivers with Δ9-tetrahydrocannabinol (THC) present showed only modest increase in odds when all concentrations were assessed (OR 1.9, 95 %CI 1.2-3.1). Benzodiazepines in drivers also gave an increase in odds (3.2, 95 %CI 1.6-6.1), but not other medicinal drugs such as antidepressants, antipsychotics and opioids. Drivers that had combinations of impairing drugs generally gave a large increase in odds, particularly combinations of alcohol with THC or benzodiazepines, and those drivers using both THC and methamphetamine.

Are non-constant rates and non-proportional treatment effects accounted for in the design and analysis of randomised controlled trials? A review of current practice.

BACKGROUND: Most clinical trials with time-to-event primary outcomes are designed assuming constant event rates and proportional hazards over time. Non-constant event rates and non-proportional hazards are seen increasingly frequently in trials. The objectives of this review were firstly to identify whether non-constant event rates and time-dependent treatment effects were allowed for in sample size calculations of trials, and secondly to assess the methods used for the analysis and reporting of time-to-event outcomes including how researchers accounted for non-proportional treatment effects. METHODS: We reviewed all original reports published between January and June 2017 in four high impact medical journals for trials for which the primary outcome involved time-to-event analysis. We recorded the methods used to analyse and present the main outcomes of the trial and assessed the reporting of assumptions underlying these methods. The sample size calculation was reviewed to see if the effect of either non-constant hazard rates or anticipated non-proportionality of the treatment effect was allowed for during the trial design. RESULTS: From 446 original reports we identified 66 trials with a time-to-event primary outcome encompassing trial start dates from July 1995 to November 2014. The majority of these trials (73%) had sample size calculations that used standard formulae with a minority of trials (11%) using simulation for anticipated changing event rates and/or non-proportional hazards. Well-established analytical methods, Kaplan-Meier curves (98%), the log rank test (88%) and the Cox proportional hazards model (97%), were used almost exclusively for the main outcome. Parametric regression models were considered in 11% of the reports. Of the trials reporting inference from the Cox model, only 11% reported any results of testing the assumption of proportional hazards. CONCLUSIONS: Our review confirmed that when designing trials with time-to-event primary outcomes, methodologies assuming constant event rates and proportional hazards were predominantly used despite potential efficiencies in sample size needed or power achieved using alternative methods. The Cox proportional hazards model was used almost exclusively to present inferential results, yet testing and reporting of the pivotal assumption underpinning this estimation method was lacking.

Prevalence of chronic kidney disease in the elderly using the ASPirin in Reducing Events in the Elderly study cohort.

AIM: The prevalence of chronic kidney disease (CKD) in the elderly is controversial because age-related decline in kidney function may not truly reflect underlying kidney disease. We estimate the baseline prevalence and predictors of CKD using the CKD Epidemiology Collaboration (CKD-EPIeGFR ) and Berlin Initiative Study 1 (BIS1eGFR ) eGFR equations in the ASPirin in Reducing Events in the Elderly (ASPREE) trial cohort of healthy older participants. METHODS: GFR was estimated using CKD-EPI and BIS1 equations. CKD was defined as eGFR <60 mL/min/1.73 m2 or ≥ 60 mL/min/1.73 m2 with urine albumin creatinine ratio (UACR) ≥ 3 mg/mmol. Logistic regression was used to identify predictors of CKD prevalence defined by each eGFR equation. RESULTS: Data for analysis were complete for 17,762 participants. Mean age was 75.1 years (SD 5); 56.4% were female, 76.4% had hypertension, 9% had diabetes mellitus. Mean CKD-EPIeGFR was 73.0 (SD 14.2), compared with mean BIS1eGFR of 62.7 (11.4). Median UACR was 0.8 (IQR 0.5, 1.5) mg/mmol. Prevalence of CKD by CKD-EPIeGFR was 27% (predominantly due to normoalbuminuric stage 3a CKD), substantially lower than 47.1% by BIS1eGFR ; the difference was predominantly driven by reclassification of individuals from G1 and G2 CKD to stage G3a without albuminuria. Increased prevalence of CKD by either equation was related to older age, hypertension, diabetes, or higher body mass index. CONCLUSIONS: Prevalence of CKD with CKD-EPIeGFR was 27%, and doubled using the elderly specific BIS1eGFR , with most participants reclassified from stage 2 to stage 3a. Increased prevalence of CKD was related older age, hypertension, diabetes, or increased body mass index.

Patterns and Predictors of Language Development from 4 to 7 Years in Verbal Children With and Without Autism Spectrum Disorder.

This study used a prospective community-based sample to describe patterns and predictors of language development from 4 to 7 years in verbal children (IQ ≥ 70) with autism spectrum disorder (ASD; n = 26-27). Children with typical language (TD; n = 858-861) and language impairment (LI; n = 119) were used for comparison. Children with ASD and LI had similar mean language scores that were lower on average than children with TD. Similar proportions across all groups had declining, increasing and stable patterns. Language progressed at a similar rate for all groups, with progress influenced by IQ and language ability at 4 years rather than social communication skills or diagnosis of ASD. These findings inform advice for parents about language prognosis in ASD.

Medication use in infants admitted with bronchiolitis.

BACKGROUND: There are no medications known that improve the outcome of infants with bronchiolitis. Studies have shown the management of bronchiolitis to be varied. OBJECTIVES: To describe medication use at the seven study hospitals from a recent multi-centre randomised controlled trial on hydration in bronchiolitis (comparative rehydration in bronchiolitis [CRIB]). METHODS: A retrospective analysis of extant data of infants between 2 months (corrected for prematurity) and 12 months of age admitted with bronchiolitis identified through the CRIB trial. CRIB study records, medical records, pathology and radiology databases were used to collect data using a standardised form and entered in a single site database. Medications investigated included salbutamol, adrenaline, steroids, ipratropium bromide, normal saline, hypertonic saline, steroids and antibiotics. RESULTS: There were 3456 infants available for analysis, of which 42.0% received at least one medication during hospitalisation. Medication use varied by site between 27.0 and 48.7%. The most frequently used medication was salbutamol (25.5%). Medication use in general, and salbutamol use in particular, increased by 8.2 and 9.3%, respectively, per month after 4 months of age; from 22.9 and 3.6% at 4 months to 81.4 and 68.8% at 11 months. In infants admitted to the intensive care unit (ICU) compared with those not admitted to ICU 81.6 and 39.5%, respectively, received medication at one point during the hospital stay. CONCLUSIONS: Medication was used for infants with bronchiolitis frequently and variably in Australia and New Zealand. Medication use increased with age. Better strategies for translating evidence into practice are needed.

Prevalence and determinants of antibiotic exposure in infants: A population-derived Australian birth cohort study.

AIM: The aim of this study was to describe antibiotic exposure in Australian infants during the first year of life, focusing on antibiotic class, indication, risk factors associated with exposure and comparison with international counterparts. METHODS: The Barwon Infant Study is a birth cohort study (n = 1074) with an unselected antenatal sampling frame from a large regional centre in Victoria, Australia. Longitudinal data on infection and medication were collected at 1, 3, 6, 9 and 12 months by parental questionnaire and from general practitioner and hospital records. Predictors of questionnaire non-completion were identified. A total of 660 infants with complete serial data were comprehensively examined. Antibiotic exposure was calculated as (i) antibiotic prescriptions and (ii) antibiotic days-exposed per person-year. RESULTS: Mean antibiotic prescription rate was 0.92 prescriptions (95% confidence interval (CI), 0.83-1.02) per person-year, with the highest rates in those aged <1 month (1.50 (95% CI, 1.09-1.91) per person-year). A total of 50.0% of infants were exposed to at least one antibiotic in their first year of life. Increasing number of siblings was associated with increased antibiotic exposure. Penicillin with extended spectrum (365 of 661 antibiotic prescriptions, 52.6%) and cephalosporins (12.0%) were the most frequently prescribed antibiotics. One fifth of antibiotics were prescribed for respiratory tract infections and bronchiolitis. CONCLUSION: Australian infants in this large population-based study are exposed to considerably more antibiotics than the majority of their international counterparts. Interventions aimed at addressing avoidable prescribing by medical practitioners and modifiable risk factors associated with antibiotic exposure may reduce antibiotic use.

Influence of weather on incidence of bronchiolitis in Australia and New Zealand.

AIM: We aimed to examine the impact of weather on hospital admissions with bronchiolitis in Australia and New Zealand. METHODS: We collected data for inpatient admissions of infants aged 2-12 months to seven hospitals in four cities in Australia and New Zealand from 2009 until 2011. Correlation of hospital admissions with minimum daily temperature, wind speed, relative humidity and rainfall was examined using linear, Poisson and negative binomial regression analyses as well as general estimated equation models. To account for possible lag between exposure to weather and admission to hospital, analyses were conducted for time lags of 0-4 weeks. RESULTS: During the study period, 3876 patients were admitted to the study hospitals. Hospital admissions showed strong seasonality with peaks in wintertime, onset in autumn and offset in spring. The onset of peak incidence was preceded by a drop in temperature. Minimum temperature was inversely correlated with hospital admissions, whereas wind speed was directly correlated. These correlations were sustained for time lags of up to 4 weeks. Standardised correlation coefficients ranged from -0.14 to -0.54 for minimum temperature and from 0.18 to 0.39 for wind speed. Relative humidity and rainfall showed no correlation with hospital admissions in our study. CONCLUSION: A decrease in temperature and increasing wind speed are associated with increasing incidence of bronchiolitis hospital admissions in Australia and New Zealand.

Intensive care unit admissions and ventilation support in infants with bronchiolitis.

OBJECTIVES: To describe the rate of intensive care unit (ICU) admission, type of ventilation support provided and risk factors for ICU admission in infants with bronchiolitis. DESIGN: Retrospective review of hospital records and Australia and New Zealand Paediatric Intensive Care (ANZPIC) registry data for infants 2-12 months old admitted with bronchiolitis. SETTING: Seven Australian and New Zealand hospitals. These infants were prospectively identified through the comparative rehydration in bronchiolitis (CRIB) study between 2009 and 2011. RESULTS: Of 3884 infants identified, 3589 charts were available for analysis. Of 204 (5.7%) infants with bronchiolitis admitted to ICU, 162 (79.4%) received ventilation support. Of those 133 (82.1%) received non-invasive ventilation (high flow nasal cannula [HFNC] or continuous positive airway pressure [CPAP]) 7 (4.3%) received invasive ventilation alone and 21 (13.6%) received a combination of ventilation modes. Infants with comorbidities such as chronic lung disease (OR 1.6 [95% CI 1.0-2.6]), congenital heart disease (OR 2.3 [1.5-3.5]), neurological disease (OR 2.2 [1.2-4.1]) or prematurity (OR 1.5 [1.0-2.1]), and infants 2-6 months of age (OR 1.5 [1.1-2.0]) were more likely to be admitted to ICU. Respiratory syncitial virus positivity did not increase the likelihood of being admitted to ICU (OR 1.1 [95% CI 0.8-1.4]). HFNC use changed from 13/53 (24.5% [95% CI 13.7-38.3]) patient episodes in 2009 to 39/91 (42.9% [95% CI 32.5-53.7]) patient episodes in 2011. CONCLUSION: Admission to ICU is an uncommon occurrence in infants admitted with bronchiolitis, but more common in infants with comorbidities and prematurity. The majority are managed with non-invasive ventilation, with increasing use of HFNC.

Accuracy of PECARN, CATCH, and CHALICE head injury decision rules in children: a prospective cohort study.

BACKGROUND: Clinical decision rules can help to determine the need for CT imaging in children with head injuries. We aimed to validate three clinical decision rules (PECARN, CATCH, and CHALICE) in a large sample of children. METHODS: In this prospective observational study, we included children and adolescents (aged <18 years) with head injuries of any severity who presented to the emergency departments of ten Australian and New Zealand hospitals. We assessed the diagnostic accuracy of PECARN (stratified into children aged <2 years and ≥2 years), CATCH, and CHALICE in predicting each rule-specific outcome measure (clinically important traumatic brain injury [TBI], need for neurological intervention, and clinically significant intracranial injury, respectively). For each calculation we used rule-specific predictor variables in populations that satisfied inclusion and exclusion criteria for each rule (validation cohort). In a secondary analysis, we compiled a comparison cohort of patients with mild head injuries (Glasgow Coma Scale score 13-15) and calculated accuracy using rule-specific predictor variables for the standardised outcome of clinically important TBI. This study is registered with the Australian New Zealand Clinical Trials Registry, number ACTRN12614000463673. FINDINGS: Between April 11, 2011, and Nov 30, 2014, we analysed 20 137 children and adolescents attending with head injuries. CTs were obtained for 2106 (10%) patients, 4544 (23%) were admitted, 83 (<1%) underwent neurosurgery, and 15 (<1%) died. PECARN was applicable for 4011 (75%) of 5374 patients younger than 2 years and 11 152 (76%) of 14 763 patients aged 2 years and older. CATCH was applicable for 4957 (25%) patients and CHALICE for 20 029 (99%). The highest point validation sensitivities were shown for PECARN in children younger than 2 years (100·0%, 95% CI 90·7-100·0; 38 patients identified of 38 with outcome [38/38]) and PECARN in children 2 years and older (99·0%, 94·4-100·0; 97/98), followed by CATCH (high-risk predictors only; 95·2%; 76·2-99·9; 20/21; medium-risk and high-risk predictors 88·7%; 82·2-93·4; 125/141) and CHALICE (92·3%, 89·2-94·7; 370/401). In the comparison cohort of 18 913 patients with mild injuries, sensitivities for clinically important TBI were similar. Negative predictive values in both analyses were higher than 99% for all rules. INTERPRETATION: The sensitivities of three clinical decision rules for head injuries in children were high when used as designed. The findings are an important starting point for clinicians considering the introduction of one of the rules. FUNDING: National Health and Medical Research Council, Emergency Medicine Foundation, Perpetual Philanthropic Services, WA Health Targeted Research Funds, Townsville Hospital Private Practice Fund, Auckland Medical Research Foundation, A + Trust.

Computed tomography for head injuries in children: Change in Australian usage rates over time.

OBJECTIVE: Paediatric head injury is a common presentation to the ED. North American studies demonstrate increasing use of computed tomography (CT) brain scan (CTB) to investigate head injury. No such data exists for Australian EDs. The aim of this study was to describe CTB use in head injury over time in eight Australian EDs. METHODS: Retrospective ED electronic database and medical imaging database audit was undertaken for the years 2001-2010 by International Classification of Diseases (ICD) 9 or 10 code for head injury in children <16 years. EDs and medical imaging departments of eight hospitals in Australia (five tertiary referral and three mixed departments). Data for ED presentations with head injury, and all CTB performed by medical imaging were merged to obtain a data set of CTB performed within 24 h for head injury-related attendances to the ED. Descriptive and comparative analysis of CTB rates was performed. RESULTS: The rate of CTB over the decade was 10.2% (95% confidence interval (CI) 9.9-10.5). The annual rate varied from 9.5% (95% CI 8.2-10.9) to 12.5% (95% CI 11.2-13.9). CTB use did not increase over time. Median year of age at time of CT scan was 4 years, with an interquartile range of 1.5-9.4 years. Overall there was a 9.2% increase in the CTB scan rate for every additional year of age at presentation (95% CI 6.6-12.1; P < 0.001). CONCLUSION: CTB use in head injuries did not increase during the study period, and rates of CTB were less than reported for North America.

Economic evaluation of nasogastric versus intravenous hydration in infants with bronchiolitis.

OBJECTIVE: Bronchiolitis is the most common lower respiratory tract infection in infants and the leading cause of hospitalisation. We aimed to assess whether intravenous hydration (IVH) was more cost-effective than nasogastric hydration (NGH) as a planned secondary economic analysis of a randomised trial involving 759 infants (aged 2-12 months) admitted to hospital with a clinical diagnosis of bronchiolitis and requiring non-oral hydration. No Australian cost data exist to aid clinicians in decision-making around interventions in bronchiolitis. METHODS: Cost data collections included hospital and intervention-specific costs. The economic analysis was reduced to a cost-minimisation study, focusing on intervention-specific costs of IVH versus NGH, as length of stay was equal between groups. All analyses are reported as intention to treat. RESULTS: Intervention costs were greater for IVH than NGH ($113 vs $74; cost difference of $39 per child). The intervention-specific cost advantage to NGH was robust to inter-site variation in unit prices and treatment activity. CONCLUSION: Intervention-specific costs account for <10% of total costs of bronchiolitis admissions, with NGH having a small cost saving across all sites.