Demonstrating the use of population level data to investigate trends in the rate, radiation dose and cost of Computed Tomography across clinical groups: Are there any areas of concern?

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.

Risk of Iron Deficiency in Women With Endometriosis: A Population-Based Prospective Cohort Study.

BACKGROUND: Endometriosis may be linked to the risk of iron deficiency through chronic systemic inflammation or heavy menstrual bleeding. No longitudinal studies, however, have examined the relationship between endometriosis and the risk of iron deficiency. METHODS: This study included 3,294 participants born from 1973 to 1978 and followed as part of the Australian Longitudinal Study on Women's Health from 2000 to 2018. Participants with endometriosis were identified using self-reported longitudinal surveys linked to administrative health records. During each survey, participants were also asked to report the diagnosis of iron deficiency, and we validated diagnoses using an administrative health database. Generalized estimating equations for binary responses with an autoregressive correlation matrix were used to examine the association between endometriosis and the risk of iron deficiency over the seven time points. FINDINGS: We found that women with endometriosis had a significantly higher risk of iron deficiency than those without endometriosis after adjusting for sociodemographic, lifestyle, reproductive, and nutrition factors (adjusted odds ratio [aOR] = 1.46; 95% confidence interval [CI] [1.29, 1.66]; p < .0001). Women with a surgically confirmed diagnosis and those with clinically suspected endometriosis had a higher risk of iron deficiency (aOR = 1.38; 95% CI [1.17, 1.64] and aOR = 1.53; 95% CI [1.30, 1.81]), respectively. These associations, however, were slightly attenuated (by 8%) when adjusted for the presence of heavy menstrual bleeding. CONCLUSIONS: Women with endometriosis are at a higher risk of developing iron deficiency than those without endometriosis. The findings suggest that iron deficiency should be concomitantly addressed during initial diagnosis and successive management of endometriosis.

Fertility treatment pathways and births for women with and without polycystic ovary syndrome-a retrospective population linked data study.

OBJECTIVE: To study the fertility treatment pathways used by women with and without polycystic ovary syndrome (PCOS) and which pathways were more likely to result in a birth. DESIGN: This retrospective national community-based cohort study used longitudinal self-report survey data (collected 1996-2022; aged 18-49 years) from women born in 1973-1978 who are participants in the Australian Longitudinal Study on Women's Health. The study also used linked administrative data on fertility treatments (1996-2021). PATIENTS: Of the 8,463 eligible women, 1,109 accessed fertility treatment and were included. EXPOSURE: Polycystic ovary syndrome diagnosis was self-reported. MAIN OUTCOME MEASURE: use of ovulation induction (OI), intrauterine insemination, and/or in vitro fertilization (IVF) was established through linked administrative data. Births were self-reported. RESULTS: One in 10 of the eligible participants had PCOS (783/7,987, 10%) and 1 in 4 of the women who used fertility treatment had PCOS (274/1,109, 25%). Women with PCOS were 3 years younger on average at first fertility treatment (M = 31.4 years, SD = 4.18) than women without PCOS (M = 34.2 years, SD = 4.56). Seven treatment pathways were identified and use differed by PCOS status. Women with PCOS were more likely to start with OI (71%; odds ratio [OR] 4.20, 95% confidence interval [CI]: 2.91, 6.07) than women without PCOS (36%). Of the women with PCOS who started with OI, 46% required additional types of treatment. More women without PCOS ended up in IVF (72% vs. 51%). Overall, 63% (701/1,109) had an attributed birth, and in adjusted regressions births did not vary by last type of treatment (IVF: 67%, reference; intrauterine insemination: 67%, OR 0.94 95% CI: 0.56, 1.58; OI: 61%, OR 0.71, 95% CI: 0.52, 0.98), or by PCOS status (OR 1.27, 95% CI: 0.91, 1.77). By age, 74% of women under 35 years (471/639) and 49% of women 35 years or older had a birth. CONCLUSION: More women with PCOS used fertility treatment but births were equivalent to women without PCOS. Most women followed clinical recommendations. Births did not differ between pathways, so there was no disadvantage in starting with less invasive treatments (although there may be financial or emotional disadvantages).

Use of CT, ED presentation and hospitalisations 12 months before and after a diagnosis of cancer in Western Australia: a population-based retrospective cohort study.

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.

Patterns of computed tomography utilisation in injury management: latent classes approach using linked administrative data in Western Australia.

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.

Excess healthcare costs of psychological distress in young women: Evidence from linked national Medicare claims data.

The prevalence of mental health disorders in young adults is increasing, yet there is limited empirical evidence on its economic consequences. We contribute to the literature by estimating the healthcare costs of psychological distress using panel data of young women (aged 18-23 years with a 5-year follow-up) from the Australian Longitudinal Study on Women's Health and linked administrative data from Medicare Australia. Our empirical strategy is based on the classical two-part model of healthcare costs with individual specific fixed-effects. We complement our analysis with a test for selection on unobservables to address potential concerns of endogeneity. We find that young women with psychological distress have 15% higher annual healthcare costs (excluding hospital costs) than women with no psychological distress. A large proportion of these costs is driven by the use of antidepressants and the services of psychiatrists and psychologists. We further find that women with psychological distress have higher out-of-pocket costs on these mental health related services compared to non-mental health specific services. Additionally, we show that the effect of psychological distress on healthcare costs is highest during the first 6 months of onset, which gradually decreases afterwards. The findings justify the importance of policy initiatives towards early prevention and treatment of psychological distress, especially among young women.

Associations of socioeconomic and health factors with dental non-attendance: A comparison of three cohorts of women.

OBJECTIVES: Most studies on factors influencing dental attendance are cross-sectional and focus on specific age groups. The associations between private ancillary health insurance, tobacco smoking, alcohol consumption and overweight/obesity with dental attendance were examined in three cohorts of Australian women of different ages using multiple waves of data over similar time periods. METHODS: Data from 10 233, 12 378 and 7892 women born in 1973-1978, 1946-1951 and 1921-1926 participating in the Australian Longitudinal Study on Women's Health were used. Poisson regression using generalized estimating equations was used to investigate factors associated with self-report of not visiting the dentist in the 12 months before completing each wave. RESULTS: The role of dental non-attendance was higher in women without insurance (versus those with insurance) in all cohorts with adjusted rate ratios (RR) of 1.52 95% CI 1.48-1.57, RR 1.45 95% CI 1.41-1.49 and RR 1.32 95% CI 1.28-1.36 in the 1973-78, 1946-51 and 1921-26 cohorts respectively. Current smokers at any intensity (versus never smokers) had a higher risk of non-attendance and the risk was strongest for women in the 1946-51 cohort who smoked ≥20 cigarettes/day (RR 1.35 95% CI 1.30-1.41). Compared with low-risk drinkers, non-drinkers were more likely to be non-attenders, but only in the two older cohorts. Women who were overweight or obese (versus healthy weight) were more likely to be non-attenders in all cohorts, with the risk of non-attendance higher with increasing BMI. CONCLUSIONS: This study emphasizes the continued need to address socioeconomic inequities in access to dental care, along with strategies to overcome barriers for those who are obese or smoke. In this study, barriers to access existed for women of all ages, indicating that interventions need to be appropriate across age groups.

A novel methodological framework was described for detecting and quantifying overdiagnosis.

OBJECTIVES: Methods to quantify overdiagnosis of screen detected cancer have been developed, but methods for quantifying overdiagnosis of noncancer conditions (whether symptomatic or asymptomatic) have been lacking. We aimed to develop a methodological framework for quantifying overdiagnosis that may be used for asymptomatic or symptomatic conditions and used gestational diabetes mellitus as an example of how it may be applied. STUDY DESIGN AND SETTING: We identify two earlier definitions for overdiagnosis, a narrower prognosis-based definition and a wider utility-based definition. Building on the central importance of the concepts of prognostic information and clinical utility of a diagnosis, we consider the following questions: within a target population, do people found to have a disease using one diagnostic strategy but found not to have the disease using another diagnostic strategy (so called 'additional diagnoses'), have an increased risk of adverse clinical outcomes without treatment (prognosis evidence), and/or a decreased risk of adverse outcomes with treatment (utility evidence)? RESULTS: Using Causal Directed Acyclic Graphs and fair umpires, we illuminate the relationships between diagnostics strategies and the frequency of overdiagnosis. We then use the example of gestational diabetes mellitus to demonstrate how the Fair Umpire framework may be applied to estimate overdiagnosis. CONCLUSION: Our framework may be used to quantify overdiagnosis in noncancer conditions (and in cancer conditions) and to guide further studies on this topic.

Association of regulatory body actions and subsequent media coverage with use of services in a fee-for-service system: a longitudinal cohort study of CT scanning in Australia.

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.

The challenges with managing polycystic ovary syndrome: A qualitative study of women's and clinicians' experiences.

OBJECTIVE: To explore clinicians' and women's views and experiences with managing polycystic ovary syndrome (PCOS). METHODS: Semi-structured interviews with 36 clinicians and 26 women with PCOS. Clinicians were recruited through advertising via relevant professional organisations, snowballing and contacting clinics across Australia. Women with PCOS were recruited through social media advertising. Transcribed audio-recordings were analysed thematically using Framework analysis. RESULTS: Findings across women with PCOS and clinician interviews were organised into three themes. Both women and clinicians experienced 1) challenges with managing PCOS, often stemming from the disparate and wide spectrum of presentations, issues with current treatment options (including limited evidence) and the long-term nature of management. Both spoke about 2) online information about PCOS and alternative treatments, including lack of relevant information and widespread misinformation. 3) Follow-up and continuity of care, where we found notable differences between women's and clinicians' expectations. CONCLUSIONS: This is the first study to explore both clinicians' and women's experiences with managing PCOS, illustrating several challenges in managing this heterogeneous condition. PRACTICE IMPLICATIONS: Clarifying and addressing patient expectations, providing personalised counselling and information according to PCOS phenotype and a multidisciplinary approach may reduce uncertainty and improve patient-centred care.

Regularity and Continuity of GP Contacts and Use of Statins Amongst People at Risk of Cardiovascular Events.

BACKGROUND: Regularity and continuity of general practitioner (GP) contacts are associated with reduced hospitalisation. Opportunities for improved medication management are cited as a potential cause. OBJECTIVE: Determine associations between continuity and regularity of primary care and statin use amongst individuals at risk of cardiovascular disease (CVD) outcomes. DESIGN: Observational cohort study using self-report and administrative data from 267,153 participants of the Sax Institute's 45 and Up Study conducted in New South Wales, Australia. from 2006 to 2009. Medicare Benefits Schedule (MBS) and Pharmaceutical Benefits Scheme (PBS) data, from Services Australia, were linked to survey, hospital and death data by the NSW Centre for Health Record Linkage. PARTICIPANTS: The 45 and Up Study participants at risk of CVD outcomes based on self-report and administrative data, divided into existing users and potential users based on dispensing records through the exposure period. MAIN MEASURES: The Continuity of Care index (COC), measuring whether patients see the same GP, and an index assessing whether GP visits are on a regular basis, measured from July 2011 to June 2012. Amongst potential users, statin initiation from July 2012 to June 2013 was assessed using logistic regression; amongst existing users, adherence was assessed from July 2012 to June 2015 using Cox regression (non-adherence being 30 days without statins). KEY RESULTS: Amongst 29,420 potential users, the most regular quintile had 1.22 times the odds of initiating statin (95%CI 1.11-1.34), while the high continuity group had an odds ratio of 1.12 (95%CI 1.02-1.24). Amongst 30,408 existing users, the most regular quintile had 0.82 the hazard of non-adherence (95%CI 0.78-0.87); the high continuity group had a hazard ratio of 0.89 (95%CI 0.84-0.94). CONCLUSIONS: Regularity and continuity of care impact on medication management. It is possible that this mediates impacts on hospitalisation. Where there is a risk of unobserved confounding, potential causal pathways should be investigated.

Rates, costs and determinants of lumbar spine imaging in population-based women born in 1973-1978: Data from the Australian Longitudinal Study on Women's Health.

OBJECTIVE: There are concerns that lumbar spine imaging represents low value care. Our aim was to examine the use of lumbar spine imaging [radiography, computed tomography (CT), magnetic resonance imaging (MRI)] over 20 years, and costs and person-level characteristics of imaging in a large cohort of Australian women. METHODS: The Australian Longitudinal Study on Women's Health (ALSWH) is a longitudinal population-based survey of women randomly selected from national health insurance scheme (Medicare) database. This study examined 13458 women born in 1973-1978 who consented to link their ALSWH and Medical Benefits Scheme records. Self-reported data on demographics, body mass index, depression, physical and mental health, and back pain were collected in each survey performed in 1996, 2000, 2003, 2006, 2009, 2012, and 2015. Data on lumbar spine imaging from 1996 to 2015 were obtained from the Medical Benefits Scheme database. RESULTS: 38.9% of women underwent some form of lumbar spine imaging over 20 years. While radiography increased from 1996 to 2011 and decreased thereafter, CT and MRI continued to increase from 1996 to 2015. In women with self-reported back pain, depression and poorer physical health were associated with imaging, with no significant differences in types of imaging. Based on imaging rates in ALSWH, the estimated costs for Australian women aged 30-39 years were AU$51,735,649 over 2011-2015. CONCLUSIONS: Lumbar spine imaging was common in population-based Australian women, with rates increasing over 20 years. Depression and poor physical health were associated with lumbar spine imaging. Raising awareness of this in clinicians is likely to result in significant cost savings if clinical guidelines are followed, with the potential of freeing resources for high value care and health outcomes.

Did changes to recommended testing criteria affect the rate of vitamin D testing among Australian women.

We examine whether new government criteria designed to reduce overuse of vitamin D testing changed testing rates in Australian women. Although testing initially declined, the reduction was not sustained. Women who had more doctor visits and who had been tested previously were more likely to have vitamin D testing. PURPOSE: Vitamin D testing increased substantially in the 2000s in many countries, particularly in women. Because of concerns about potential over-testing, in 2014, the Australian criteria for subsidised testing were restricted to those at high risk of vitamin D deficiency. We aimed to describe vitamin D testing trends in Australian women (1996 to 2019) and investigate sociodemographic and health factors associated with testing under the new criteria. METHODS: We used joinpoint regression to assess changes in national testing trends in Australian women (aged 15+ years) using universal health insurance system data. Additionally, we investigated the factors associated with vitamin D testing through Poisson regression with robust error variance using survey and linked insurance system data from participants born 1946-51 in the Australian Longitudinal Study on Women's Health (ALSWH). RESULTS: Between 1996 and 2013, vitamin D testing rates increased in all age groups. Rates declined between 2013 and 2016, but increased again between 2016 and 2019. In the ALSWH cohort, a higher likelihood of testing under the new criteria was associated with 12 or more doctor visits per year compared to two or fewer visits per year (relative risk (RR) 1.85; 95% CI 1.61-2.12), and women who had two or more vitamin D tests between 2012 and 2014 compared to no test (RR 1.55; 95% CI 1.48-1.62). CONCLUSION: The introduction of new criteria has not led to sustained declines in testing. High testing rates and repeated testing suggest that over-testing for vitamin D deficiency in Australian women is still occurring.

Trends in knee magnetic resonance imaging, arthroscopies and joint replacements in older Australians: still too much low-value care?

BACKGROUND: The objective of the study is to describe temporal trends and regional variations in the use of knee magnetic resonance imaging (MRI), knee arthroscopy and total knee replacement surgery in Australians older than 55 years. METHODS: Design: A retrospective descriptive study using routinely collected administrative data. MAIN OUTCOME MEASURES: Age-standardized rates of knee MRI, knee arthroscopy and knee replacement surgery from 2003 to 2017. RESULTS: Knee MRI rates increased from 216/100 000 in 2003, to 1509/100 000 in 2017 (sevenfold relative increase). Knee arthroscopy rates initially increased from 372/100 000 in 2003 to a maximum of 475/100 000 in 2011, before declining to 283/100 000 in 2017. Knee joint replacement surgery increased from 535/100 000 in 2003 to 840/100 000 in 2017 (57% relative increase). The use of MRI increased in all regions of Australia but to differing extents. Knee arthroscopy rates declined in all regions from 2011, but to differing extents. Knee joint replacement surgery increased at roughly the same rate across Australia. CONCLUSION: Knee arthroscopy rates increased before declining modestly in more recent years, most likely in response to evidence against its effectiveness. Knee MRI rates have continued to increase despite consistent recommendations against their routine use in the evaluation of knee pain. Future research could investigate potential drivers of the increased use of MRI, and of the continued use of arthroscopy. Further exploration of the extent to which either procedure explains the increase in numbers of knee joint replacements is also warranted.

Impact of a diagnosis of polycystic ovary syndrome on diet, physical activity and contraceptive use in young women: findings from the Australian Longitudinal Study of Women's Health.

STUDY QUESTION: Do diet, physical activity and contraceptive use change after receiving a diagnosis of polycystic ovary syndrome (PCOS)? SUMMARY ANSWER: Using longitudinal data 12 months apart, young women newly diagnosed with PCOS were more likely to stop using contraception but did not change their physical activity or vegetable intake. WHAT IS KNOWN ALREADY: Diagnostic criteria for PCOS have widened to capture more women, despite limited evidence of the benefits and harms. Possible benefits of a PCOS diagnosis are that it may help women with family planning and motivate them to implement healthy lifestyle changes to reduce the reproductive, metabolic and cardiovascular risks associated with PCOS. However, there are no empirical studies investigating how women respond to a diagnosis of PCOS with respect to their health behaviour, and longitudinal population-based studies are lacking. STUDY DESIGN, SIZE, DURATION: This is a longitudinal analysis of two waves of data collected 12 months apart from the cohort born 1989-1995 in the Australian Longitudinal Survey on Women's Health, a population-based cohort study. Women in this cohort were first surveyed in 2012-2013, aged 18-23 years. PARTICIPANTS/MATERIALS, SETTING, METHODS: Women who responded to the 2014 survey (aged 19-24, n = 11 344) and 2015 survey (aged 20-25, n = 8961) were included. Using logistic regression, multinomial logistic regression and linear regression, change in vegetable intake, physical activity and contraceptive use were compared for women newly diagnosed with PCOS to women not reporting a diagnosis of PCOS. Changes in psychological distress and BMI were also examined. MAIN RESULTS AND THE ROLE OF CHANCE: Young women reporting a new diagnosis of PCOS were no more likely to increase their vegetable intake or physical activity than women not reporting a PCOS diagnosis. Women newly diagnosed with PCOS were 3.4 times more likely to stop using contraception during the 12-month study period than women without PCOS (14% versus 4%, 95% CI = 2.3 to 5.1, P < 0.001). This difference remained significant after controlling for demographics, chronic conditions associated with PCOS, endometriosis, BMI and psychological distress (P < 0.001). LIMITATIONS, REASONS FOR CAUTION: All data was self-reported including PCOS diagnosis, assessment of diet quality was limited to vegetable intake only. The exact timing of diagnosis within the 12-month period and whether the women intended to conceive are unknown. The number of women reporting a new diagnosis of PCOS was also relatively small. WIDER IMPLICATIONS OF THE FINDINGS: These findings suggest that a diagnosis of PCOS may not produce short-term benefits by way of improving health behaviour. The observed reduction in contraception use suggests some women may be at increased risk of unplanned pregnancies, highlighting the importance of counselling about contraceptive needs. Both potential benefits and harms must be considered when determining the appropriateness of a PCOS diagnosis. STUDY FUNDING/COMPETING INTEREST(S): The Australian Longitudinal Study on Women's Health is funded by the Australian Government Department of Health. BWM reports consultancy for ObsEva, Merck, Merck KGaA and Guerbet. No further competing interests exist. TRIAL REGISTRATION NUMBER: N/A.

How have advances in CT dosimetry software impacted estimates of CT radiation dose and cancer incidence? A comparison of CT dosimetry software: Implications for past and future research.

OBJECTIVE: Organ radiation dose from a CT scan, calculated by CT dosimetry software, can be combined with cancer risk data to estimate cancer incidence resulting from CT exposure. We aim to determine to what extent the use of improved anatomical representation of the adult human body "phantom" in CT dosimetry software impacts estimates of radiation dose and cancer incidence, to inform comparison of past and future research. METHODS: We collected 20 adult cases for each of three CT protocols (abdomen/pelvis, chest and head) from each of five public hospitals (random sample) (January-April inclusive 2010) and three private clinics (self-report). Organ equivalent and effective dose were calculated using both ImPACT (mathematical phantom) and NCICT (voxelised phantom) software. Bland-Altman plots demonstrate agreement and Passing-Bablok regression reports systematic, proportional or random differences between results. We modelled the estimated lifetime attributable risk of cancer from a single exposure for each protocol, using age-sex specific risk-coefficients from the Biologic Effects of Ionizing Radiation VII report. RESULTS: For the majority of organs used in epidemiological studies of cancer incidence, the NCICT software (voxelised) provided higher dose estimates. Across the lifespan NCICT resulted in cancer estimates 2.9%-6.6% and 14.8%-16.3% higher in males and females (abdomen/pelvis) and 7.6%-19.7% and 12.9%-26.5% higher in males and females respectively (chest protocol). For the head protocol overall cancer estimates were lower for NCICT, but with greatest disparity, >30% at times. CONCLUSION: When the results of previous studies estimating CT dose and cancer incidence are compared to more recent, or future, studies the dosimetry software must be considered. Any change in radiation dose or cancer risk may be attributable to the software and phantom used, rather than-or in addition to-changes in scanning practice. Studies using dosimetry software to estimate radiation dose should describe software comprehensively to facilitate comparison with past and future research.

Lifetime risk of prostate cancer overdiagnosis in Australia: quantifying the risk of overdiagnosis associated with prostate cancer screening in Australia using a novel lifetime risk approach.

OBJECTIVES: To quantify the risk of overdiagnosis associated with prostate cancer screening in Australia using a novel lifetime risk approach. DESIGN: Modelling and validation of the lifetime risk method using publicly available population data. SETTING: Opportunistic screening for prostate cancer in the Australian population. PARTICIPANTS: Australian male population (1982-2012). INTERVENTIONS: Prostate-specific antigen testing for prostate cancer screening. PRIMARY AND SECONDARY OUTCOME MEASURES: Primary: lifetime risk of overdiagnosis in 2012 (excess lifetime cancer risk adjusted for changing competing mortality); Secondary: lifetime risk of prostate cancer diagnosis (unadjusted and adjusted for competing mortality); Excess lifetime risk of prostate cancer diagnosis (for all years subsequent to 1982). RESULTS: The lifetime risk of being diagnosed with prostate cancer increased from 6.1% in 1982 (1 in 17) to 19.6% in 2012 (1 in 5). Using 2012 competing mortality rates, the lifetime risk in 1982 was 11.5% (95% CI 11.0% to 12.0%). The excess lifetime risk of prostate cancer in 2012 (adjusted for changing competing mortality) was 8.2% (95% CI 7.6% to 8.7%) (1 in 13). This corresponds to 41% of prostate cancers being overdiagnosed. CONCLUSIONS: Our estimated rate of overdiagnosis is in agreement with estimates using other methods. This method may be used without the need to adjust for lead times. If annual (cross-sectional) data are used, then it may give valid estimates of overdiagnosis once screening has been established long enough for the benefits from the early detection of non-overdiagnosed cancer at a younger age to be realised in older age groups.

An Australian community jury to consider case-finding for dementia: Differences between informed community preferences and general practice guidelines.

BACKGROUND: Case-finding for dementia is practised by general practitioners (GPs) in Australia but without an awareness of community preferences. We explored the values and preferences of informed community members around case-finding for dementia in Australian general practice. DESIGN, SETTING AND PARTICIPANTS: A before and after, mixed-methods study in Gold Coast, Australia, with ten community members aged 50-70. INTERVENTION: A 2-day citizen/community jury. Participants were informed by experts about dementia, the potential harms and benefits of case-finding, and ethical considerations. PRIMARY AND SECONDARY OUTCOMES: We asked participants, "Should the health system encourage GPs to practice 'case-finding' of dementia in people older than 50?" Case-finding was defined as a GP initiating testing for dementia when the patient is unaware of symptoms. We also assessed changes in participant comprehension/knowledge, attitudes towards dementia and participants' own intentions to undergo case-finding for dementia if it were suggested. RESULTS: Participants voted unanimously against case-finding for dementia, citing a lack of effective treatments, potential for harm to patients and potential financial incentives. However, they recognized that case-finding was currently practised by Australian GPs and recommended specific changes to the guidelines. Participants increased their comprehension/knowledge of dementia, their attitude towards case-finding became less positive, and their intentions to be tested themselves decreased. CONCLUSION: Once informed, community jury participants did not agree case-finding for dementia should be conducted by GPs. Yet their personal intentions to accept case-finding varied. If case-finding for dementia is recommended in the guidelines, then shared decision making is essential.