Katy J L Bell

• MBChB, MMed (clin epi), PhD
• Senior Researcher at The University of Sydney

Despite increasing attention on health literacy and the inclusion of grade reading level recommendations in guidelines, it remains unclear if lowering the grade reading level of written health information to specific target grades improves patient-related outcomes. To assess whether grade reading level of written information affects knowledge, perc...

Background Clinical care contributes to at least 50% of the greenhouse gas (GHG) emissions of healthcare. This includes the 40% of healthcare that is harmful or low value, adding avoidable emissions without improving health or quality of care. Clinicians are well-placed to mitigate emissions associated with the provision of clinical care. This stud...

Background Limited data exist on the motivations and expectations of participants when enrolling in dermatology clinical trials, including melanoma early detection trials. Understanding participant motivators for research engagement has been identified as a prioritized area for trial methodology research. Objective The study aimed to determine mot...

The Society of Obstetric Medicine Australia and New Zealand (SOMANZ) Hypertension in Pregnancy Guideline 2023 is the first evidence‐based guideline for hypertensive disorders of pregnancy that has been developed to the standards of the Australian National Health and Medical Research Council (NHMRC). This article describes the methodology, challenge...

Introduction Many types of prostate cancer present minimal risk to a man’s lifespan or well-being, but existing terminology makes it difficult for men to distinguish these from high-risk prostate cancers. This study aims to explore whether using an alternative label for low-risk prostate cancer influences management choice and anxiety levels among...

Objectives To determine the annual numbers of first ICD insertions in New South Wales during 2005–2020; to examine health outcomes for people who first received ICDs during this period. Study design Retrospective cohort study; analysis of linked administrative health data. Setting, participants All first insertions of ICDs in NSW, 2005–2020. Mai...

BACKGROUND Limited data exist on the motivations and expectations of participants when enrolling in dermatology clinical trials, including melanoma early detection trials. Understanding participant motivators for research engagement has been identified as a prioritized area for trial methodology research. OBJECTIVE The study aimed to determine mot...

Background Digital mammography has replaced film mammography in breast-screening programs globally, including Australia. This led to an increase in the rate of detection, but whether there was increased detection of clinically important cancers is uncertain. Methods In this population-wide retrospective cohort study in New South Wales, Australia s...

Objectives To quantify the proportion of melanoma diagnoses (invasive and in situ) in the USA that might be overdiagnosed. Design In this ecological study, incidence and mortality data were collected from the Surveillance, Epidemiology and End Results 9 registries database. DevCan software was used to calculate the cumulative lifetime risk of bein...

Using scoping review methods, we systematically searched multiple online databases for publications in the first year of the pandemic that proposed pragmatic population or health system-level solutions to health inequities. We found 77 publications with proposed solutions to pandemic-related health inequities. Most were commentaries, letters, or ed...

Objectives The objective of this study is to map the range and variety of direct-to-consumer (DTC) tests advertised online in Australia and analyse their potential clinical utility and implications for medical overuse. Design Systematic online search of DTC test products in Google and Google Shopping. DTC test advertisements data were collected an...

A shift in practice by anaesthetists away from anaesthetic gases with high global warming potential towards lower emission techniques (e.g. total intravenous anaesthesia) could result in significant carbon savings for the health system. The purpose of this qualitative interview study was to understand anaesthetists’ perspectives on the carbon footp...

Objectives To review evaluations of the diagnostic accuracy of coronavirus disease 2019 (COVID‐19) rapid antigen tests (RATs) approved by the Therapeutic Goods Administration (TGA) for self‐testing by ambulatory people in Australia; to compare these estimates with values reported by test manufacturers. Study design Systematic review of publication...

Highlights •The negative findings from the linked study suggest breast density may not affect prognosis after a breast cancer diagnosis. •Cancer stage and overdiagnosis are potential confounders of the relationship between breast density and health outcomes. •The prognostic value of changes in mammographic density over time may be explored in futur...

Introduction: Post-trial follow-up studies have become increasingly important to investigate the long-term effectiveness of interventions after randomized controlled trials (RCTs). Legacy effects refer to intervention effects that are only observed after the trial has ended and are not the direct effects observed during the trial period. However,...

Background Population mammographic screening for breast cancer has led to large increases in the diagnosis and treatment of ductal carcinoma in situ (DCIS). Active surveillance has been proposed as a management strategy for low-risk DCIS to mitigate against potential overdiagnosis and overtreatment. However, clinicians and patients remain reluctant...

Background: Previous mixed findings on the associations between whole blood (WB) donation and risk of cardiovascular diseases (CVD) may in part reflect inadequate adjustment for the "healthy donor effect" (HDE). Methods: We used the Sax Institute's 45 and Up Study linked with blood donation history and other health-related databases to examine t...

Importance Adherence, both in research trials and in clinical practice, is crucial to the success of interventions. There is limited guidance on strategies to increase adherence and the measurement and reporting of adherence in trials of melanoma self-management practices. Objective This scoping review aimed to describe (1) strategies to improve a...

Background: Active surveillance (AS) mitigates harms from overtreatment of low-risk prostate lesions. Recalibration of diagnostic thresholds to redefine which prostate lesions are considered "cancer" and/or adopting alternative diagnostic labels could increase AS uptake and continuation. Methods: We searched PubMed and EMBASE to October 2021 for...

BACKGROUND After treatment for a localised melanoma, patients attend routinely scheduled clinics to monitor for new primary or recurrent melanoma. Patient-led surveillance (skin self-examination with patient-performed teledermoscopy) is an alternative model of follow-up that could replace some routinely scheduled visits. OBJECTIVE To assess the ac...

Background After treatment for a localized melanoma, patients attend routinely scheduled clinics to monitor for new primary or recurrent melanoma. Patient-led surveillance (skin self-examination with patient-performed teledermoscopy) is an alternative model of follow-up that could replace some routinely scheduled visits. Objective This study aims...

This cross-sectional study examines the variability of readability scores across widely used online calculators.

This framework focuses on the importance of the consideration of the downstream intermediate and long-term health outcomes when a change to a screening program is introduced. The authors present a methodology for utilising the relationship between screen-detected and interval cancer rates to infer the benefits and harms associated with a change to...

Background. Overdiagnosis is an accepted harm of cancer screening, but studies of prostate cancer screening decision aids have not examined provision of information important in communicating the risk of overdiagnosis, including overdiagnosis frequency, competing mortality risk, and the high prevalence of indolent cancers in the population. Methods...

Importance: Appropriate diagnosis of attention-deficit/hyperactivity disorder (ADHD) can improve some short-term outcomes in children and adolescents, but little is known about the association of a diagnosis with their quality of life (QOL). Objective: To compare QOL in adolescents with and without an ADHD diagnosis. Design, setting, and partic...

AimsHuman health is intrinsically linked with planetary health. But planetary resources are currently being degraded and this poses an existential threat to human health and the sustainability of our healthcare systems. The aims of this study were to (1) describe an approach to integrate environmental impacts in a cost analysis; and (2) demonstrate...

A shared decision-making approach is considered optimal in primary cardiovascular disease (CVD) prevention. Evidence-based patient decision aids can facilitate this but do not always meet patients’ health literacy needs. Coronary artery calcium (CAC) scans are increasingly used in addition to traditional cardiovascular risk scores, but the availabi...

Background Globally, ADHD diagnoses have increased substantially and there is concern that this trend does not necessarily reflect improved detection of cases but that overdiagnosis may be occurring. We directly compared ADHD diagnoses with ADHD‐related behaviours and looked for changes across time among Australian children in a large, population‐b...

Background Non-invasive prenatal screening (NIPS) is being increasingly used by expectant parents. Much provision of this test in Australia is occurring in clinical settings where specialised genetic counselling is unavailable. Potential psychosocial consequences of NIPS remain largely unexplored. Aim This study aimed to understand potential psych...

Purpose It is not known how underlying subclinical papillary thyroid cancer (PTC) differs by age. This meta-analysis of autopsy studies investigates how subclinical PTC prevalence changes over the lifetime. Methods We searched PubMed, Embase, and Web of Science databases from inception to May 2021 for studies that reported the prevalence of PTC fo...

Linked Article: Whiteman et al. Br J Dermatol 2022; 187:515–522.

Objective To undertake an assessment of the health, financial and environmental impacts of a well-recognised example of low-value care; inappropriate vitamin D testing. Design Combination of systematic literature search, analysis of routinely collected healthcare data and environmental analysis. Setting Australian healthcare system. Participants...

Background Current clinician-led melanoma surveillance models require frequent routinely scheduled clinic visits, with associated travel, cost, and time burden for patients. Patient-led surveillance is a new model of follow-up care that could reduce health care use such as clinic visits and medical procedures and their associated costs, increase ac...

Background The growing number of melanoma patients who need long-term surveillance increasingly exceeds the capacity of the dermatology workforce, particularly outside of metropolitan areas. Digital technologies that enable patients to perform skin self-examination and send dermoscopic images of lesions of concern to a dermatologist (mobile teleder...

BACKGROUND The large and growing number of melanoma patients who need long term surveillance increasingly exceeds capacity of the dermatology workforce, particularly outside of metropolitan areas. Digital technologies that enable patients to do skin self-examination and send dermoscopic images of lesions of concern to a dermatologist (mobile telede...

Objectives Current practice monitors women with low-grade cervical abnormalities at 12 months later, but women with high-grade cervical abnormalities (cervical intraepithelial neoplasia (CIN) 2 and 3) routinely receive immediate treatment to remove abnormal cells. There is evidence of increased risk of obstetric complications following invasive tre...

Background Overdiagnosis is an accepted harm of cancer screening, but studies of prostate cancer screening decision aids have not examined provision of information important in communicating the risk of overdiagnosis, including: overdiagnosis frequency, competing mortality risk, and the high prevalence of indolent cancers in the population. Method...

Aim: To investigate the impact of adenotonsillectomy (ADT) and adenoidectomy (AD) on child health and evaluated their post-operative complications. Methods: We included all children aged <16 years undergoing ADT (tonsillectomy ± adenoidectomy) or AD in New South Wales, Australia, 2008-2017. Health information was obtained from administrative hos...

Background: Non-invasive prenatal screening (NIPS) is being increasingly used by expectant parents. Much provision of this test in Australia is occurring in clinical settings where specialised genetic counselling is unavailable, such as general practice. Potential psychosocial consequences from this kind of prenatal genetic screening remain largel...

Since 2020, hundreds of thousands of more deaths than expected have been observed across the globe. Amid the coronavirus 2019 (COVID-19) pandemic, current research priorities are to control the spread of infection and minimise loss of life. However, there may be future opportunities to learn from the pandemic to build a better healthcare system tha...

Importance: Coronary artery calcium scores (CACS) are used to help assess patients' cardiovascular status and risk. However, their best use in risk assessment beyond traditional cardiovascular factors in primary prevention is uncertain. Objective: To find, assess, and synthesize all cohort studies that assessed the incremental gain from the addi...

Risk prediction models are potentially useful tools for health practitioners and policy makers. When new predictors are proposed to add to existing models, the improvement of discrimination is one of the main measures to assess any increment in performance. In assessing such predictors, we observed two paradoxes: 1) the discriminative ability withi...

Objective: Care for fear of cancer recurrence (FCR) is considered the most common unmet need among cancer survivors. Yet the prevalence of FCR and predisposing factors remain inconclusive. To support targeted care, we provide a comprehensive overview of the prevalence and severity of FCR among cancer survivors and patients, as measured using the s...

Background Population trends in PSA testing and prostate cancer incidence do not perfectly correspond. We aimed to better understand relationships between trends in PSA testing, prostate cancer incidence and mortality in Australia and factors that influence them. Methods We calculated and described standardised time trends in PSA tests, prostate b...

Background The MEL-SELF trial is a randomised controlled trial of patient-led surveillance compared to clinician-led surveillance in people treated for localised cutaneous melanoma (stage 0, I, II). The primary trial aim is to determine if patient led-surveillance compared to clinician-led surveillance increases the proportion of participants who a...

Objectives Methods to quantify overdiagnosis of screen detected cancer have been developed, but methods for quantifying overdiagnosis of non-cancer 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 conditio...

Aim: To assess whether the observed numbers and seasonality of deaths in Australia during 2020 differed from expected trends based on 2015-19 data. Methods: We used provisional death data from the Australian Bureau of Statistics, stratified by state, age, sex and cause of death. We compared 2020 deaths with 2015-19 deaths using interrupted time...

This study aimed to explore the impact of health literacy on psychosocial and behavioural outcomes for people who were not at high risk of cardiovascular disease receiving a hypothetical blood pressure reading of 135/85 mmHg. We performed a secondary analysis of data from a national sample of Australians aged 40 to 50 years (n = 1318) recruited onl...

Background/objectives Pathology laboratories are required to determine or estimate the measurement uncertainty for all quantitative results, but there is no literature on the uncertainty in margin measurements for skin cancer excisions. Methods Six pathologists measured 4–14 histological margins in each of 10 basal cell carcinoma. Results The mea...

BACKGROUND Current clinician-led melanoma surveillance models require frequent routinely scheduled clinic visits, with associated travel, cost, and time burden for patients. Patient-led surveillance is a new model of follow-up care that could reduce health care use such as clinic visits and medical procedures and their associated costs, increase ac...

Objective To determine the impact of test measurement variation on misclassification of prediabetes and diabetes in the US adult population. Study Design and Setting Data from adults with no prior diagnosis of diabetes in the 2015-2016 National Health and Nutrition Examination Survey (NHANES) were used to simulate populations of US adults eligible...

Importance Patient-led surveillance is a promising new model of follow-up care following excision of localized melanoma. Objective To determine whether patient-led surveillance in patients with prior localized primary cutaneous melanoma is as safe, feasible, and acceptable as clinician-led surveillance. Design, Setting, and Participants This was...

We are in a health emergency precipitated by climate change.¹ As well as physical health threats, climate change and its effects are adversely affecting Australians’ mental health,² and worsening the health inequities suffered by vulnerable populations. In response, the Australian health care community must both adapt to increased demand and to det...

Background Australian Red Cross Lifeblood (Lifeblood) advises donors to visit their general practitioner (GP) for medical follow‐up if they are deferred from donating due to having a lower than acceptable level of hemoglobin (Hb) and/or serum ferritin (iron‐related deferrals). Methods We used the Sax Institute's 45 and Up Study data linked to Life...

Background: Active surveillance for cervical intraepithelial neoplasia 2 (CIN2) would allow time for most cases to regress naturally and in turn avoid potentially unnecessary and harmful treatment. Aim: To determine reasons for choosing active surveillance over surgery among women given a hypothetical diagnosis of CIN2. Materials and methods:...

Analytical performance specifications (APS) for measurands describe the minimum analytical quality requirements for their measurement. These APS are used to monitor and contain the systematic (trueness/ bias) and random errors (precision/ imprecision) of a laboratory measurement to ensure the results are “fit for purpose” in informing clinical deci...

Background: Recalibrating diagnostic thresholds or using alternative labels may mitigate overdiagnosis and overtreatment of microscopic papillary thyroid cancer (mPTC). We aimed to identify and collate relevant epidemiological evidence on mPTC, to assess the case for recalibration and/or new labels. Methods: We searched EMBASE and PubMed databas...

Background Analyses of legacy effects are mainly based on post-trial follow-up study after initial randomized controlled trials (RCT). However, the differential event rates between arms may cause a violation of randomization balance and induce selection bias in the post-trial analysis. We conducted a simulation to illustrate the bias and explore if...

Importance Thyroid cancer is more common in women than in men, but the associated causes of these differences are not fully understood. Objective To compare sex-specific thyroid cancer rates in the US to the prevalence of subclinical thyroid cancer at autopsy. Data Sources Data on thyroid cancer incidence and mortality by sex among US adults (≥18...

Background Many blood collection agencies are generating important data on donor health outcomes using large‐scale blood donor cohort studies. Such studies can be very effective when donors provide access to linkage of their data to external health databases, and storage and genomic testing of their blood sample. In this study, we aimed to assess t...

Background Most subsequent new primary or recurrent melanomas might be self-detected if patients are trained to systematically self-examine their skin and have access to timely medical review (patient-led surveillance). Routinely scheduled clinic visits (clinician-led surveillance) is resource-intensive and has not been shown to improve health outc...

Importance Reported increases in attention-deficit/hyperactivity disorder (ADHD) diagnoses are accompanied by growing debate about the underlying factors. Although overdiagnosis is often suggested, no comprehensive evaluation of evidence for or against overdiagnosis has ever been undertaken and is urgently needed to enable evidence-based, patient-c...

Background Recent US guidelines lowered the threshold for diagnosing hypertension while other international guidelines use alternative/no labels for the same group (blood pressure [BP], <140/90 mm Hg). We investigated potential benefits and harms of hypertension and high-normal BP labels, compared with control, among people at lower risk of cardiov...

Background Accurate seroprevalence estimates of SARS-CoV-2 in different populations could clarify the extent to which current testing strategies are identifying all active infection, and hence the true magnitude and spread of the infection. Our primary objective was to identify valid seroprevalence studies of SARS-CoV-2 infection and compare their...

Testing for SARS-CoV-2 infection is key in managing the current pandemic. More than 1700 preprints and peer reviewed journal articles evaluating tests for SARS-CoV-2 infection have been published as of January 2021. However, evaluations of these studies have identified many methodological issues, leading to a high risk of bias and difficulties appl...

Background: Most subsequent new primary or recurrent melanomas might be self-detected if patients are trained to systematically self-examine their skin and have access to timely medical review (patient-led surveillance). Routinely scheduled clinic visits (clinician-led surveillance) is resource-intensive and has not been shown to improve health out...

Background Pathologists sometimes disagree over the histopathologic diagnosis of melanoma. ‘Over‐calling’ and ‘under‐calling’ of melanoma may harm individuals and healthcare systems. Objectives To estimate the extent of ‘over‐calling’ and ‘under‐calling’ of melanoma for a population undergoing one excision per person and to model the impact of pot...

Objective To investigate framing of active surveillance as a management option for cervical intraepithelial neoplasia (CIN)2 in women of childbearing age. Methods We conducted a between-subjects factorial (2 × 2) randomised experiment. Women aged 25–40 living in Australia were presented with the same hypothetical pathway of testing human papilloma...

Mendelian randomization is an epidemiological approach to making causal inferences using observational data. It makes use of the natural randomization that occurs in the generation of an individual’s genetic makeup in a way that is analogous to the study design of a randomized controlled trial and uses instrumental variable analysis where the genet...

Objectives The objective of the study was to assess the methods used, and potential for bias, in posttrial studies of cardiovascular disease (CVD) where legacy effects may be estimated. Study Design and Setting We undertook a methods review of posttrial studies after randomized controlled trials (RCTs) of interventions to prevent CVD. For each inc...

Background: Knowing the prevalence of true asymptomatic coronavirus disease 2019 (COVID-19) cases is critical for designing mitigation measures against the pandemic. We aimed to synthesize all available research on asymptomatic cases and transmission rates. Methods: We searched PubMed, Embase, Cochrane COVID-19 trials, and Europe PMC for primary...

Objectives Several guidelines for the evaluation of laboratory tests for severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) infection have recommended establishing an a priori definition of minimum clinical performance specifications before test selection and method evaluation. Methods Using positive (PPV) and negative predictive values...

Background Medical tests provide important information to guide clinical management. Overtesting, however, may cause harm to patients and the healthcare system, including through misdiagnosis, false positives, false negatives and overdiagnosis. Clinicians are ultimately responsible for test requests, and are therefore ideally positioned to prevent...

Background: The prevalence of true asymptomatic COVID-19 cases is critical to policy makers considering the effectiveness of mitigation measures against the SARS-CoV-2 pandemic. We aimed to synthesize all available research on the asymptomatic rates and transmission rates where possible. Methods: We searched PubMed, Embase, Cochrane COVID-19 trials...

Objective: To estimate the extent that BP measurement variability may drive over- and underdiagnosis of 'hypertension' when measurements are made according to current guidelines. Methods: Using data from the National Health and Nutrition Examination Survey and empirical estimates of within-person variability, we simulated annual SBP measurement...