OBJECTIVES:Administrative medicine dispensing data often omit prescribed duration, which is important for research on adherence or other pharmacoepidemiological topics. While the reverse waiting time distribution (rWTD) method has been widely used to estimate prescribed durations, its accuracy in real-world dispensing data is unknown. We assessed the performance of the rWTD method against the actual prescribed duration recorded in the Rotterdam Study. METHODS:100 725 antihypertensive (AHT) prescriptions from 2018 to 2019 were extracted from the Rotterdam Study's medicine data. Data were constructed into five scenarios with increasing variability in the number of medicines included and variations in prescribed duration. The rWTD with 10 random index dates with or without adjustment for the quantity of dispensed medicine was conducted in all scenarios. Relative differences and limit of agreement ratio based on Bland-Altman analysis were used to examine agreement between estimated and actual prescribed durations. RESULTS:rWTD models without adjustment for the quantity of dispensed medicine performed well only in the most homogenous scenario. In scenarios with greater data variability, performance improved significantly when adjusted for the quantity of dispensed medicine. Relative difference decreased from ≥ 65% in models without covariates to ≤ 20% with covariates, and the limit of agreement ratio decreased from ≥ 36.8 in models without covariates to ≤ 5.3 with covariates. Stratification analysis by subclass of the AHT medicines provided similar results. CONCLUSIONS:The study demonstrated that as data variability increased, the accuracy of the rWTD estimations decreased. However, the rWTD can produce good estimates (relative difference from 0% to 28%) of prescribed duration for AHT medicines, with the highest accuracy in the model adjusting for the quantity of dispensed medicine or stratification of the data with a relative difference less than 20% and the limit of agreement ratio less than 5.3 for the estimation at the 90th percentile of inter-arrival density. Since this validation was limited to antihypertensive medicines, generalizing the finding to other chronic-use medicines should be undertaken with caution.

BACKGROUND:Neonatal and puerperal sepsis are major manifestations of invasive group B streptococcal (Streptococcus agalactiae; iGBS) infections. International data indicate the importance of iGBS infections among non-pregnant adults. AIMS:To describe the burden of iGBS infections in Western Australia (WA) between 2000 and 2018 in terms of incidence, length of hospitalisation and all-cause 30- and 90-day mortality. METHODS:This was a retrospective, population-based study using linked data from the state government-owned pathology provider, hospitalisations and death registrations. Children and adults with isolation of GBS in a normally sterile site or a hospital-based diagnosis of iGBS infection were included. RESULTS:There were 2861 cases; just over a quarter (n = 768) were aged 0-1 year. Half of the cases were among females (1438 of 2861), and the median age was 39 years. Incidence increased over the study period, with an age- and sex-adjusted incidence rate ratio for year of 1.08 (95% confidence interval (CI) 1.06-1.09). The incidence in 2018 was 9.5 cases (95% CI 8.3-10.6 cases) per 100 000 population. The proportion of cases among those aged 0-1 year fell across the period, while the relative incidence in older age groups increased. The median length of hospital stay was 7 days (interquartile range 4-15 days), and mortality at 30 days was 3% (95 of 2861). CONCLUSIONS:iGBS cases increased across the period 2000-2018 in WA, with older adults making up a higher proportion of cases over time. Preventive efforts among older patients, including potentially through vaccination, may reverse this increase.

Introduction: Increases in computed tomography (CT) use may not always reflect clinical need or improve outcomes. This study aimed to demonstrate how population level data can be used to identify variations in care between patient groups, by analysing system-level changes in CT use around the diagnosis of new conditions. Methods: Retrospective repeated cross-sectional observational study using West Australian linked administrative records, including 504,723 adults diagnosed with different conditions in 2006, 2012 and 2015. For 90 days pre/post diagnosis, CT use (any and 2+ scans), effective dose (mSv), lifetime attributable risk (LAR) of cancer incidence and mortality from CT, and costs were assessed. Results: CT use increased from 209.4 per 1000 new diagnoses in 2006 to 258.0 in 2015; increases were observed for all conditions except neoplasms. Healthcare system costs increased for all conditions but neoplasms and mental disorders. Effective dose increased substantially for respiratory (+2.5 mSv, +23.1%, P < 0.001) and circulatory conditions (+2.1 mSv, +15.4%, P < 0.001). The LAR of cancer incidence and mortality from CT increased for endocrine (incidence +23.4%, mortality +18.0%) and respiratory disorders (+21.7%, +23.3%). Mortality LAR increased for circulatory (+12.1%) and nervous system (+11.0%) disorders. The LAR of cancer incidence and mortality reduced for musculoskeletal system disorders, despite an increase in repeated CT in this group. Conclusions: Use and costs increased for most conditions except neoplasms and mental and behavioural disorders. More strategic CT use may have occurred in musculoskeletal conditions, while use and radiation burden increased for respiratory, circulatory and nervous system conditions. Using this high-level approach we flag areas requiring deeper investigation into appropriateness and value of care.

Introduction Calcium channel blockers (CCB), a commonly prescribed antihypertensive (AHT) medicine, may be associated with increased risk of breast cancer. The proposed study aims to examine whether long-term CCB use is associated with the development of breast cancer and to characterise the dose–response nature of any identified association, to inform future hypertension management.Methods and analysis The study will use data from 2 of Australia’s largest cohort studies; the Australian Longitudinal Study on Women’s Health, and the 45 and Up Study, combined with the Rotterdam Study. Eligible women will be those with diagnosed hypertension, no history of breast cancer and no prior CCB use at start of follow-up (2004–2009). Cumulative dose-duration exposure to CCB and other AHT medicines will be captured at the earliest date of: the outcome (a diagnosis of invasive breast cancer); a competing risk event (eg, bilateral mastectomy without a diagnosis of breast cancer, death prior to any diagnosis of breast cancer) or end of follow-up (censoring event). Fine and Gray competing risks regression will be used to assess the association between CCB use and development of breast cancer using a generalised propensity score to adjust for baseline covariates. Time-varying covariates related to interaction with health services will also be included in the model. Data will be harmonised across cohorts to achieve identical protocols and a two-step random effects individual patient-level meta-analysis will be used.Ethics and dissemination Ethical approval was obtained from the following Human research Ethics Committees: Curtin University (ref No. HRE2022-0335), NSW Population and Health Services Research Ethics Committee (2022/ETH01392/2022.31), ACT Research Ethics and Governance Office approval under National Mutual Acceptance for multijurisdictional data linkage research (2022.STE.00208). Results of the proposed study will be published in high-impact journals and presented at key scientific meetings.Trial registration number NCT05972785.

Background This study aimed to describe the out-of-pocket costs incurred by patients diagnosed with high-grade glioma (HGG) and their carers in the standard care arm of the Care-IS trial in the 6 to 8 months following their diagnosis.Methods Carers completed monthly cost surveys detailing the out-of-pocket costs incurred by patients and carers over a 6-month period. Seventy carers reported out-of-pocket costs at baseline (within 2 months following patient diagnosis), and a maximum of 50% of participants reported costs in any subsequent month. Costs were adjusted to 2023 AUD and reported as medians with an interquartile range. Demographic factors were assessed to determine if any were significantly associated with being in the first or fourth quartile of total out-of-pocket costs at baseline.Results Median monthly costs for patient-carer dyads were highest at baseline ($535[IQR:$170-$930]), and 2 months post-recruitment ($314 [IQR:$150-$772]). The largest contributors to patient-carer costs were patient health service use and patient medications. Patient and carer health service use and medication costs varied over time. The median health service use and medication out-of-pocket costs for patients and carers were mostly below $100 per month; however, there was a large variance in the upper 75th percentile for these cost categories. No factors were significantly associated with higher baseline out-of-pocket costs.Conclusions A HGG diagnosis has a significant and sustained financial impact on people who are diagnosed and their carers. Patients experience significant additional costs relating to their diagnosis and travel to receive care, and their carers also continue to experience sustained costs whilst managing the additional tasks associated with informal caregiving.

(1) Background: Pulmonary embolism (PE) can be fatal. Computed tomography pulmonary angiography (CTPA) can accurately diagnose PE, but it should be used only when reasonable pre-test probability exists. Overtesting with CTPA exposes patients to excess ionizing radiation and contrast media, while PE overdiagnosis leads to the treatment of small emboli unlikely to cause harm. This study assessed trends in CTPA use and diagnostic yield. We also assessed trends in PE hospitalizations and mortality to indicate PE severity. (2) Methods: Analysis of Western Australian linked administrative data for 2003–2015 including hospitalizations, emergency department (ED) attendances, and CTPA performed at hospitals. Age-sex standardized trends were calculated for CTPA use, PE hospitalizations, and mortality (as a proxy for severity). Logistic regression assessed diagnostic yield of CTPA following unplanned ED presentations. (3) Results: CTPA use increased from 3.3 per 10,000 person-years in 2003 (95% CI 3.0–3.6) to 17.1 per 10,000 person-years (16.5–17.7) in 2015. Diagnostic yield of CTPA increased from 12.7% in 2003 to 17.4% in 2005, declining to 12.2% in 2015 (p = 0.049). PE hospitalizations increased from 3.8 per 10,000 (3.5–4.1) in 2003 to 5.2 per 10,000 (4.8–5.5) in 2015. Mortality remained constant at 0.50 per 10,000 (0.39–0.62) in 2003 and 0.42 per 10,000 (0.32–0.51) in 2015. (4) Conclusions: CTPA increased from 2003 to 2015, while diagnostic yield decreased, potentially indicating overtesting. PE mortality remained constant despite increasing hospitalizations, likely indicating a higher proportion of less severe cases. As treatment can be harmful, this could represent overdiagnosis.

Purpose Whilst computed tomography (CT) imaging has been a vital component of injury management, its increasing use has raised concern regarding ionising radiation exposure. This study aims to identify latent classes (underlying patterns) of CT use over a 3-year period following the incidence of injury and factors predicting the observed patterns. Method A retrospective observational cohort study was conducted in 21,544 individuals aged 18 + years presenting to emergency departments (ED) of four tertiary public hospitals with new injury in Western Australia. Mixture modelling approach was used to identify latent classes of CT use over a 3-year period post injury. Results Amongst injured people with at least one CT scan, three latent classes of CT use were identified including a: temporarily high CT use (46.4%); consistently high CT use (2.6%); and low CT use class (51.1%). Being 65 + years or older, having 3 + comorbidities, history with 3 + hospitalisations and history of CT use before injury were associated with consistently high use of CT. Injury to the head, neck, thorax or abdomen, being admitted to hospital after the injury and arriving to ED by ambulance were predictors for the temporarily high use class. Living in areas of higher socio-economic disadvantage was a unique factor associated with the low CT use class. Conclusions Instead of assuming a single pattern of CT use for all patients with injury, the advanced latent class modelling approach has provided more nuanced understanding of the underlying patterns of CT use that may be useful for developing targeted interventions.

Objective To examine the use of CT, emergency department (ED)-presentation and hospitalisation and in 12 months before and after a diagnosis of cancer.Design Population-based retrospective cohort study.Setting West Australian linked administrative records at individual level.Participants 104 009 adults newly diagnosed with cancer in 2004–2014.Main outcome measures CT use, ED presentations, hospitalisations.Results As compared with the rates in the 12th month before diagnosis, the rate of CT scans started to increase from 2 months before diagnosis with an increase in both ED presentations and hospitalisation from 1 month before the diagnosis. These rates peaked in the month of diagnosis for CT scans (477 (95% CI 471 to 482) per 1000 patients), and for hospitalisations (910 (95% CI 902 to 919) per 1000 patients), and the month prior to diagnosis for ED (181 (95% CI 178 to 184) per 1000 patients) then rapidly reduced after diagnosis but remained high for the next 12 months. While the patterns of the health services used were similar between 2004 and 2014, the rate of the health services used during after diagnosis was higher in 2014 versus 2004 except for CT use in patients with lymphohaematopoietic cancer with a significant reduction.Conclusion Our results showed an increase in demand for health services from 2 months before diagnosis of cancer. Increasing use of health services during and post cancer diagnosis may warrant further investigation to identify factors driving this change.

OBJECTIVE:The professional service review (PSR) is an Australian Government agency aiming to reduce inappropriate practices funded via Medicare, Australia's public insurer. Our objective was to examine changes in CT following the 2008-2009 PSR annual report, which noted excessive CT use. DESIGN:Interrupted time series analysis examined trends in CT use following the 2008-2009 PSR report, estimating both change in the immediate rate of CT and the slope of the trend in usage postintervention. SETTING:Medicare-funded imaging (most out-of-hospital imaging) in Australia. PARTICIPANTS:Patients receiving Medicare-funded CT and other imaging. INTERVENTION:The 2008-2009 PSR report highlighted concerns regarding excessive CT use. Two providers were financially penalised for CT overuse with these cases detailed in the PSR report and highlighted in an associated Report to the Professions, distributed to 50 000 providers. Media articles on radiation risks followed. OUTCOMES:Quarterly rates of out-of-hospital CT, MRI (as a comparator), and all other Medicare-funded diagnostic imaging examinations 2001-2019. RESULTS:CT scanning increased from 4663.5 per 100 000 person-years in 2001 to 14 506 in 2019 (211% increase), with substantial variation by type and anatomical region. The 2008-2009 PSR report was followed by an immediate reduction in CT scanning of 237.7 CTs per 100 000 people per quarter (95% CI -333.4 to -141.9) though growth in use soon continued at the preintervention rate. The degree of change in utilisation following the report differed between states/territories and by scan type, both in terms of the immediate change and the slope. For other diagnostic imaging modalities, there was an increase in the slope, while for MRI there was no change in either parameter. CONCLUSION:Actions consisting of financial disincentives for service overtesting and provider/public education components may limit excessive use of diagnostic imaging in fee-for-service systems, however, effects observed here were only short lived.

Background This study evaluated changes in regularity of general practitioner (GP) contact (the pattern of visits over time) and the impact of regularity on diabetes-related hospitalisation following introduction of care co-ordination incentives. Methods Linked primary care, hospital and death records covered West Australian adults from 1991-2004. Different eras were evaluated based on incentive program changes and model fit, to assess changes in regularity. Changes in regularity, derived from the variance in the number of days between GP contacts, were evaluated using ordered logistic regression. The impact of regularity on hospitalisation rates and costs were evaluated. Results Two eras prior to program introduction (1991/92-1994/9 and 1995/96-1998/99), and one after (1999/2000-2002/03) were assessed. Among 153,455 at risk of diabetes-related hospitalisation GP contact became slightly less regular in the second era, though there was no change from the second to third era. The most regular decile had 5.5% fewer hospitalisations (95% CI -0.9% to -9.9%) and lower per-patient costs (difference AU$115, CI -$63 to -$167) than the least regular. Associations were similar in each era. Conclusions Ongoing relationships between GPs and patients are important to maintaining health. Historical data provide the opportunity to assess the impact of care co-ordination incentives on relationships.

ObjectiveHigh use of CT scanning has raised concern due to the potential ionising radiation exposure. This study examined trends of CT during admission to tertiary hospitals and its associations with length of stay (LOS), readmission and mortality.DesignRetrospective observational study from 2003 to 2015.SettingWest Australian linked administrative records at individual level.Participants2 375 787 episodes of tertiary hospital admission in adults aged 18+ years.Main outcome measuresLOS, 30-day readmissions and mortality stratified by CT use status (any, multiple (CTs to multiple areas during episode), and repeat (repeated CT to the same area)).MethodsMultivariable regression models were used to calculate adjusted rate of CT use status. The significance of changes since 2003 in the outcomes (LOS, 30-day readmission and mortality) was compared among patients with specific CT imaging status relative to those without.ResultsBetween 2003 and 2015, while the rate of CT increased 3.4% annually, the rate of repeat CTs significantly decreased −1.8% annually and multiple CT showed no change. Compared with 2003 while LOS had a greater decrease in those with any CT, 30-day readmissions had a greater increase among those with any CT, while the probability of mortality remained unchanged between the any CT/no CT groups. A similar result was observed in patients with multiple and repeat CT scanning, except for a significant increase in mortality in the recent years in the repeat CT group.ConclusionThe observed pattern of increase in CT utilisation is likely to be activity-based funding policy-driven based on the discordance between LOS and readmissions. Meanwhile, the repeat CT reduction aligns with a more selective strategy of use based on clinical severity. Future research should incorporate in-hospital and out-of-hospital CT to better understand overall CT trends and potential shifts between settings over time.

Epidemiologic data on invasive group C/G Streptococcus (iGCGS) infections are sparse internationally. Linked population-level hospital, pathology, and death data were used to describe the disease burden in Western Australia, Australia, during 2000–2018 compared with that of invasive group A Streptococcus (GAS, Streptococcus pyogenes) infections. Of 1,270 cases, 866 (68%) occurred in men. Patients with iGCGS infection were older (median age 62 years) than those with invasive GAS (median age 44 years; p<0.0001). The age and sex-adjusted incidence rate ratio by year was 1.08 (95% CI 1.07–1.09). The incidence rate ratio for Indigenous compared with non-Indigenous Australians was 3.6 (95% CI 3.0–4.3). The all-cause 90-day death rate was 9% for iGCGS infection compared with 7% for invasive GAS (p = 0.03). iGCGS infection was more common in men and older persons and had a higher death rate, perhaps reflecting the effect of age and comorbidities on incidence and death.

BACKGROUND:The aim was to determine the cost-effectiveness of radioguided occult lesion localization using 125I-labelled seeds (125I seeds) versus hookwire localization in terms of incremental cost per reoperation avoided for women with non-palpable breast cancer undergoing breast-conserving surgery.METHODS:This study was based on a multicentre RCT with eight study sites comprising seven public hospitals and one private hospital. An Australian public health system perspective was taken. The primary effectiveness outcome for this study was reoperations avoided. Cost-effectiveness was expressed as an incremental cost-effectiveness ratio (ICER). One-way and probabilistic sensitivity analyses were used to explore uncertainty. The willingness to pay (additional cost of localization using 125I seeds justified by reoperation cost avoided) was set at the weighted, top-down cost of reoperation. Costs were in 2019 Australian dollars ($1 was equivalent to €0.62).RESULTS:The reoperation rate was 13.9 (95 per cent confidence interval 10.7 to 18.0) per cent for the 125I seed group and 18.9 (14.8 to 23.8) per cent for the hookwire localization group. The ICER for 125I seed versus hookwire localization was $4474 per reoperation averted. The results were most sensitive to uncertainty around the probability of reoperation. Accounting for transition probability and cost uncertainty for 125I seed localization, there was a 77 per cent probability that using 125I seeds would be cost-effective, with a willingness to pay of $7693 per reoperation averted.CONCLUSION:Radioguided occult lesion localization using 125I seeds is likely to be cost-effective, because the marginal (additional) cost compared with hookwire localization is less than the cost of reoperations avoided.

The Australian and New Zealand governments have allocated significant funding to advance efforts towards a group A Streptococcus (Strep A) vaccine. The argument for Strep A vaccine development has to date focussed on prevention of non-invasive disease (e.g. pharyngitis) and immune-mediated complications (especially rheumatic heart disease). Because of the poorer prognosis and theoretically more precisely known burden of invasive, compared to non-invasive disease, exploration of the burden of invasive Strep A disease could lend further support to the vaccine business case. This narrative review critically assesses the Australian incidence of invasive Strep A disease. Case notification data were first assessed through government sources, expressing annual incidence as cases per 100 000 population. Published literature accessed through PubMed and MEDLINE was assessed to March 2020. Where estimates could be updated by replicating reported methods with publicly available data, this was performed. Invasive Strep A disease is currently notifiable in Queensland and the Northern Territory only. The magnitude, degree of certainty and recency of estimates vary by state/territory and between sub-populations, including higher incidence among Indigenous Australians compared to non-Indigenous Australians. According to inpatient records from 2017 to 2018, the Australian incidence of invasive Strep A disease was 8.3 per 100 000. However, this is likely to be an underestimate. Preventing invasive Strep A disease is an important use for a Strep A vaccine. This narrative review highlights deficiencies in our current understanding of the Australian disease burden. These difficulties would be overcome by nationally consistent mandatory case reporting.

Objective To quantify the burden of invasive group A Streptococcus (GAS) disease in Western Australia during 2000-2018. Design, setting Population-based data linkage study: Hospital Morbidity Data Collection (HMDC; all WA public and private hospital records), PathWest pathology data (government-owned pathology services provider), and death registrations. Participants People with invasive GAS disease, defined by an isolate from a normally sterile site (PathWest) or a hospital-based principal ICD-10-AM diagnosis code (HMDC). Main outcome measures Incidence of invasive GAS disease; median length of hospital stay; all-cause mortality. Results We identified 2237 cases of GAS disease during 2000-2018; 1283 were in male patients (57%). 1950 cases had been confirmed by GAS isolates from normally sterile tissues (87%; including 1089 from blood [56% of cases] and 750 from tissue [38%]). The age-standardised incidence increased from 2.0 (95% CI, 1.4-2.7) cases per 100 000 population in 2000 to 9.1 (95% CI, 7.9-10.2) cases per 100 000 in 2017 (by year, adjusted for age group and sex: incidence rate ratio [IRR], 1.09; 95% CI, 1.08-1.10). Incidence was consistently higher among Indigenous than non-Indigenous Australians (year-adjusted IRR, 13.1; 95% CI, 11.3-15.1). All-cause 30-day mortality was 5% (116 deaths), and 90-day mortality 7% (156 deaths); 30-day mortality, adjusted for age group and sex, was not statistically significantly different for cases involving Indigenous or non-Indigenous patients (adjusted odds ratio, 0.8; 95% CI, 0.6-1.1). Conclusions The incidence of invasive GAS disease in WA increased between 2000 and 2018, particularly among Indigenous Australians. Mandatory notification of invasive GAS disease would therefore be appropriate. The social determinants of differences in incidence should be addressed, and other relevant host, pathogen, and health system factors investigated.

BACKGROUND:This study investigated trends in computed tomography (CT) utilization across different triage categories of injury presentations to tertiary emergency departments (EDs) and associations with diagnostic yield measured by injury severity, hospitalization and length of stay (LOS), and mortality.METHODS:A total of 411,155 injury-related ED presentations extracted from linked records from Western Australia from 2004 to 2015 were included in the retrospective study. The use of CT scanning and diagnostic yield measured by rate of diagnosis with severe injury, hospitalizations and LOS, and mortality were captured annually for injury-related ED presentations. Multivariable regression models were used to calculate the annual adjusted rate of CT scanning for injury presentations and hospitalizations across triage categories, diagnosis with severe injury, LOS, and mortality. The significance of changes observed was compared among patients with CT imaging relative to those without CT.RESULTS:While the number of ED presentations with injury increased by 65% from 2004 to 2015, the use of CT scanning in these presentations increased by 176%. The largest increase in CT use was among ED presentations triaged as semi-/nonurgent (+256%). Injury presentations with CT, compared to those without, had a higher rate of diagnosis with moderate/severe injury and hospitalization but no difference in LOS and mortality. The probability/rate observed in the outcomes of interest had a greater decrease over time in those with CT scanning compared with those without CT scanning across triage categories.CONCLUSIONS:The reduction in diagnostic yield in terms of injury severity and hospitalization found in our study might indicate a shift toward overtesting using CT in ED for injury or a higher use of CT to assist in the management of injuries. This helps health care policymakers consider whether the current increase in CT use meets the desired levels of quality and efficient care.

Abstract Background Epidemiological studies on sarcoma from Australia are lacking, as previous studies have focused on a sarcoma type (e.g. soft tissue) or anatomical sites. Planning for centralised referral and management of sarcoma, which improves outcomes, is aided by accurate understanding of the disease burden. Methods Routinely linked cancer registry, hospital morbidity and death registration data from 1982 to 2016 for Western Australia (WA) were used. All new sarcoma cases among WA residents were included, using the European Information Network on Rare Cancers definitions. Measures of interest were incidence, prevalence, relative survival and cancer-related hospitalisations. Results The age-standardised incidence and prevalence for bone sarcoma was stable, relative to soft tissue sarcoma (STS), which increased over time. For 2012-16, the combined sarcoma crude annual incidence was 7.3 per 100,000, with the majority being STS (incidence of 5.9 per 100,000). Five-year relative survival for the period 2012-16 was higher for bone sarcoma (71%) than for STS (65%). The cumulative cost for cancer-related hospitalisations was an estimated $(Australian, 2019) 29 million. Conclusions STS incidence increased over time in WA, with an increasing proportion of people diagnosed aged ≥65 years. This study provides insights into the burden of sarcoma in WA. Use of a European sarcoma definition facilitated comparison of incidence and survival with values reported in Europe. Key messages This study describes the epidemiology of sarcoma, a heterogeneous group of mesenchymal tumours, in WA. The linked data approach facilitated assessment of health service utilisation; this approach may be useful for application in other settings.

IntroductionBecause sarcomas are a rare group of malignancies, centralised referral and management improves outcomes. To plan centralised care, an understanding of disease burden is essential. Epidemiological studies on sarcoma from Australia are lacking, as previous studies have focused on a sarcoma type (e.g. soft tissue) or anatomical sites. As notification of all cancer diagnoses is required in Western Australia (WA), routinely collected data provides a platform to improve understanding of the sarcoma burden and associated cost. Objectives and ApproachThis study aimed to determine incidence, prevalence, relative survival and cost of cancer-related hospitalisation for sarcoma in WA. Routinely linked cancer registry, hospital morbidity and death registration data from 1982 to 2016 were used. All new sarcoma cases among WA residents were included, using the Information Network on Rare Cancers (RARECARENet) definitions. To provide a reference point, comparisons were made with female breast, colorectal, prostate and lung cancers. ResultsThe age-standardised incidence and prevalence of STS increased over time, while bone sarcoma remained more stable. For 2012-16, the combined sarcoma crude annual incidence was 7.3 per 100,000, with the majority of these soft tissue sarcoma (STS, incidence of 5.9 per 100,000). Five-year relative survival for the period 2012-16 for STS was 65% for STS, while five-year relative survival was 71% for bone sarcoma. This was higher than lung cancer, but lower than breast, colorectal and prostate cancer. Cancer-related hospitalisations cost an estimated $(Australian) 29.1 million over the period. Conclusion / ImplicationsThe analysis of health service use showed sarcoma had a lower mean episode of cancer-related hospitalisation compared to the reference cancers in 2016, but the mean cost per prevalent person was higher for sarcoma than for female breast, colorectal and prostate cancer. STS incidence increased over time in WA, with an increasing proportion of people diagnosed aged ≥65 years.

BACKGROUND:Cancer survival has improved in Western Australia (WA) over recent decades. Loss of life expectancy (LOLE) is a useful measure for assessing cancer survival at a population-level. Some previous studies estimating LOLE have required a minimum follow-up beyond diagnosis to reduce the impact of modelled extrapolation, while others have not. The first aim of this study was to assess the impact of minimum length of follow-up on LOLE estimates for people diagnosed in 2006 with female breast, colorectal, prostate, lung, cervical, combined oesophageal and stomach cancers, and melanoma. Based on these results, the second aim was to assess temporal changes in LOLE for these cancer types for diagnoses between 1982 and 2016.METHODS:Person-level linked cancer registry and mortality data were used for invasive primary cancer diagnoses for WA residents aged 15-89 years. The analysis for aim one included cases diagnosed from 1982 to the end of 2006, followed to the end of 2006 (i.e. no minimum follow-up), 2011 (i.e. five years minimum follow-up, assuming survival) or 2016 (i.e. 10 years minimum follow-up). To achieve the second study aim, the diagnostic period was extended to the end of 2016. Life expectancy estimates were obtained after fitting flexible parametric relative survival models. Single-year age and sex-specific death rates were used as a reference to estimate LOLE and proportionate loss of life expectancy.RESULTS:Temporal changes were not reported for prostate, cervical, oesophageal and stomach cancers or melanoma, due to differences in LOLE estimates by minimum follow-up time, or estimate imprecision. Marked reductions in LOLE were observed for female breast and colorectal cancer. There was minimal absolute reduction for lung cancer, where LOLE remained high.CONCLUSION:This study considered the appropriateness of including recent cancer diagnoses when assessing temporal changes in LOLE, finding variation in estimates with differing minimum follow-up or high parameter uncertainty for most included cancer types. Temporal changes in LOLE in-turn reflected changes in the life expectancy of the general population, cancer detection and management. These factors must be considered when estimating and interpreting LOLE estimates.