Diagnosing overdiagnosis: conceptual challenges and suggested solutions

Kairos in diagnostics

Kairos has been a key concept in medicine for millennia and is frequently understood as "the right time" in relation to treatment. In this study we scrutinize kairos in the context of diagnostics. This has become highly topical as technological developments have caused diagnostics to be performed ever earlier in the disease development. Detecting risk factors, precursors, and predictors of disease (in biomarkers, pre-disease, and pre-pre-disease) has resulted in too early diagnoses, i.e., overdiagnoses. Nonetheless, despite vast advances in science and technology, diagnoses also come too late. Accordingly, timing diagnostics right is crucial. In this article we start with giving a brief overview of the etymology and general use of the concepts of kairos and diagnosis. Then we delimit kairos in diagnostics by analysing "too early" and "too late" diagnosis and by scrutinizing various phases of diagnostics. This leads us to define kairos of diagnostics as the time when there is potential for sufficient information for making a diagnosis that is most helpful for the person. It allows us to conclude that kairos is as important in diagnostics as in therapeutics.

Clinical decision making of post-treatment disease

Root-filled teeth presenting with signs of post-treatment disease is a common finding in virtually every dental practice. There is both empirical and experimental evidence that, as long as the condition is asymptomatic, it is often left untreated. Professional judgements and decision making in endodontics as in any medical discipline are based on qualified estimations of the probability and the value of relevant outcomes. In this paper we describe various aspects of clinical decision making in general, from a descriptive as well as a normative point of view, but with a particular focus on the condition of the root-filled tooth with post-treatment disease. We review how attention to various types of uncertainties are relevant for the decision-making process. Additionally, we discuss the nature of value judgements and different concepts of health and disease which are important for understanding the complexity of the clinical decision-making process. We also refer to a set of principal rules that can guide the clinician's decision making in every-day practice in front of a case with endodontic post-treatment disease. Finally, we provide some aspects on the sometime cumbersome decision whether to go for a non-surgical or surgical method, whenever a decision on retreatment has been made.

Managing the moral expansion of medicine

Science and technology have vastly expanded the realm of medicine. The numbers of and knowledge about diseases has greatly increased, and we can help more people in many more ways than ever before. At the same time, the extensive expansion has also augmented harms, professional responsibility, and ethical concerns. While these challenges have been studied from a wide range of perspectives, the problems prevail. This article adds value to previous analyses by identifying how the moral imperative of medicine has expanded in three ways: (1) from targeting experienced phenomena, such as pain and suffering, to non-experienced phenomena (paraclinical signs and indicators); (2) from addressing present pain to potential future suffering; and (3) from reducing negative wellbeing (pain and suffering) to promoting positive wellbeing. These expansions create and aggravate problems in medicine: medicalization, overdiagnosis, overtreatment, risk aversion, stigmatization, and healthism. Moreover, they threaten to infringe ethical principles, to distract attention and responsibility from other competent agents and institutions, to enhance the power and responsibility of professionals, and to change the professional-beneficiary relationship. In order to find ways to manage the moral expansion of medicine, four traditional ways of setting limits are analyzed and dismissed. However, basic asymmetries in ethics suggest that it is more justified to address people’s negative wellbeing (pain and suffering) than their positive wellbeing. Moreover, differences in epistemology, indicate that it is less uncertain to address present pain and suffering than future wellbeing and happiness. Based on these insights the article concludes that the moral imperative of medicine has a gradient from pain and suffering to wellbeing and happiness, and from the present to the future. Hence, in general present pain and suffering have normative priority over future positive wellbeing.

Too Much, Too Mild, Too Early: Diagnosing the Excessive Expansion of Diagnoses

Tremendous scientific and technological advances have vastly improved diagnostics. At the same time, false alarms, overdiagnosis, medicalization, and overdetection have emerged as pervasive challenges undermining the quality of healthcare and sustainable clinical practice. Despite much attention, there is no clarity on the classification and handling of excessive diagnoses. This article identifies three basic types of excessive diagnosing: too much, too mild, and too early. Correspondingly, it suggests three ways to reduce excess and advance high value care: we must stop diagnosing new phenomena, mild conditions, and early signs that do not give pain, dysfunction, and suffering.

Dediagnosing - a novel framework for making people less ill

Diagnosing constitutes a substantial part of healthcare work and triggers a wide range of actions including the prescription of medicines. Dediagnosing is proposed as a novel framework for removing diagnoses that do not contribute to the reduction of persons' suffering and should be introduced to make people less ill. Dediagnosing comes together with other efforts to reduce overuse, such as deimplementation, deprescribing, decommissioning, and disinvestment. Because diagnoses may influence identity construction and social rights, dediagnosing must be conducted in close collaboration with the patient.

Visualizing the Invisible: Invisible Waste in Diagnostic Imaging

There is extensive waste in diagnostic imaging, at the same time as there are long waiting lists. While the problem of waste in diagnostics has been known for a long time, the problem persists. Accordingly, the objective of this study is to investigate various types of waste in imaging and why they are so pervasive and persistent in today's health services. After a short overview of different conceptions and types of waste in diagnostic imaging (in radiology), we identify two reasons why these types of waste are so difficult to address: (1) they are invisible in the healthcare system and (2) wasteful imaging is driven by strong external forces and internal drivers. Lastly, we present specific measures to address wasteful imaging. Visualizing and identifying the waste in diagnostic imaging and its ingrained drivers is one important way to improve the quality and efficiency of healthcare services.

The Effect of Limiting the Scan Range of Computed Tomography Pulmonary Angiography (to Reduce Radiation Exposure) on the Detection of Pulmonary Embolism: A Systematic Review

(1) Background: Computed tomography pulmonary angiography (CTPA) is the standard imaging test for the evaluation of acute pulmonary embolism (PE), but it is associated with patients' exposure to radiation. Studies have suggested that radiation exposure can be reduced without compromising PE detection by limiting the scan range (the z-axis, going from up to down); (2) Methods: A literature search was conducted in MEDLINE and EMBASE on 17 July 2021. Studies were included if they enrolled patients who had undergone a CTPA and described the yield of PE diagnoses, number of missed filling defects and/or other diagnoses using a reduced z-axis in comparison to a full-length scan. To assess risk of bias, we modified an existing risk of bias tools for observational studies, the Newcastle-Ottawa Scale. Results were synthesized in a narrative review. Primary outcomes were the number of missed PE diagnoses (based on at least one filling defect) and filling defects; the secondary outcome was the number of other missed findings; (3) Results: Eleven cohort studies and one case-control study were included reporting on a total of 3955 scans including 1025 scans with a diagnosis of PE. Six different reduced scan ranges were assessed; the most studied was from the top of the aortic arch to below the heart, in which no PEs were missed (seven studies). One sub-segmental PE was missed when the scan coverage was 10 cm starting from the bottom of the aortic arch and 14.7 cm starting from the top of the arch. Five studies that reported on other findings all found that other diagnoses were missed with a reduced z-axis. Most of the included studies had a high risk of bias; (4) Conclusions: CTPA scan coverage reduction from the top of aortic arch to below the heart reduced radiation exposure without affecting PE diagnoses, but studies were generally at high risk of bias.

How do people understand overtesting and overdiagnosis? Systematic review and meta-synthesis of qualitative research

RATIONALE

The public should be informed about overtesting and overdiagnosis. Diverse qualitative studies have examined public understandings of this information. A synthesis was needed to systematise the body of evidence and yield new, generalisable insights.

AIM

Synthesise data from qualitative studies exploring patient and public understanding of overtesting and overdiagnosis.

METHODS

We searched Scopus, CINAHL, Ovid MEDLINE and PsycINFO databases from inception to March 18, 2020. We included published English-language primary studies exploring the perspectives of patients/the public about overtesting/overdiagnosis from any setting, year and relating to any condition. Only qualitative parts of mixed-methods studies were synthesised. We excluded studies that only examined overtreatment or sampled people with specialised medical knowledge. Two authors independently selected studies, extracted data, assessed the methodological quality of included studies using the CASP tool, and assessed confidence in the synthesis findings using the GRADE-CERQual approach. Data was analysed using thematic meta-synthesis, utilising descriptive and interpretive methods.

RESULTS

We synthesised data from 21 studies, comprising 1638 participants, from 2754 unique records identified. We identified six descriptive themes, all graded as moderate confidence (indicating they are likely to reasonably represent the available evidence): i) high confidence in screening and testing; ii) difficulty in understanding overuse; iii) acceptance that overuse can be harmful; iv) rejection or problematisation of overuse; v) limited impacts of overuse information on intended test and screening uptake; vi) desire for information and shared decision-making regarding overuse. The descriptive themes were underpinned by two analytic themes: i) perceived intrinsic value of information and information gathering, and; ii) differences in comprehension and acceptance of overuse concepts.

CONCLUSIONS

This study identified novel and important insights about how lay people interpret overuse concepts. It will guide the development of more effective public messages about overuse, highlighting the importance of interpretative frameworks in these communications.

Why Does Cancer Screening Persist Despite the Potential to Harm?

Population screening for early-stage cancer or cancer precursors began in the mid-twentieth century, with the goal of reducing suffering from cancer illness and lengthening average life by preventing cancer deaths. Since the establishment of cancer screening, concerns have emerged that it may be doing considerable harm; despite this, screening practices have remained relatively intractable. This intractability in the face of harm is the central problematic of my analysis. I reinterpret a large study of breast, cervical and prostate cancer screening completed recently by our Australian research group, working across empirical bioethics, public health and social science. I suggest three reasons why cancer screening might persist as it does, and thus reach conclusions about what might be required to make cancer screening systems more responsive to the potential for harm.

Overdiagnosis: one concept, three perspectives, and a model

Defining, estimating, communicating about, and dealing with overdiagnosis is challenging. One reason for this is because overdiagnosis is a complex phenomenon. In this article we try to show that the complexity can be analysed and addressed in terms of three perspectives, i.e., that of the person, the professional, and the population. Individuals are informed about overdiagnosis based on population-based estimates. These estimates depend on professionals' conceptions and models of disease and diagnostic criteria. These conceptions in turn depend on individuals' experience of suffering, and on population level outcomes from diagnostics and treatment. As the personal, professional, and populational perspectives are not easy to reconcile, we must address them explicitly and facilitate interaction. Population-based estimates of overdiagnosis must be more directly informed by personal need for information. So must disease definitions and diagnostic criteria. Only then can individuals be appropriately informed about overdiagnosis.

The match between need and use of health services among healthy under-fives in Denmark: A register-based national cohort study

OBJECTIVES

To study a potential positive association (referred to as 'a match') between the need for health service (expressed by a mortality risk score) and observed health service utilisation among healthy Danish under-fives. Further, municipal differences in the match were examined to motivate focused comparisons between the organisation of regional health services.

DESIGN

Register-based national cohort study.

PARTICIPANTS

The population of 1,246,599 Danish children born 1997-2016 who survived until date of first discharge to the home after birth without a diagnosis of severe chronic disease.

MAIN OUTCOME MEASURES

Hazard ratios (HR) for a doubling of the mortality rate were calculated for the following health services: total contacts, inpatient contacts (admission > 1 day), outpatient contacts, general practitioner contacts, specialist contacts, medication use, and vaccinations.

RESULTS

The use of total contacts, inpatient contacts (> 1 day) and general practitioner contacts as well as medication matched with the mortality risk score, HRs between 1.027 (1.026 to 1.028) and 1.111 (1.108 to 1.113), whereas outpatient and specialist contacts as well as vaccinations did not, HRs between 0.913 (0.912 to 0.915) and 0.991 (0.991 to 0.991). There were some remarkable differences among the 98 Danish municipalities.

CONCLUSIONS

We found some match between need and use for total contacts, inpatient contacts (> 1 day), contacts with general practitioner, and medication use although the associations were relatively weak. For outpatient and specialist contacts, the mismatch may be related to services not addressing potentially fatal disease whereas for vaccination there was a small mismatch. Our results indicate local discrepancies in diagnosis, and a low adjusted utilisation of hospital admissions in Aarhus compared to the other three major cities in Denmark suggests that a comparison of the organisation of services could be useful.

Defining and Evaluating Overdiagnosis in Mental Health: A Meta-Research Review

BACKGROUND

Overdiagnosis is thought to be common in some mental disorders, but it has not been defined or examined systematically. Assessing overdiagnosis in mental health requires a consistently applied definition that differentiates overdiagnosis from other problems (e.g., misdiagnosis), as well as methods for quantification.

OBJECTIVES

Our objectives were to (1) describe how the term "overdiagnosis" has been defined explicitly or implicitly in published articles on mental disorders, including usages consistent (overdefinition, overdetection) and inconsistent (misdiagnosis, false-positive test results, overtreatment, overtesting) with accepted definitions of overdiagnosis; and (2) identify examples of attempts to quantify overdiagnosis.

METHOD

We searchedPubMed through January 5, 2019. Articles on mental disorders, excluding neurocognitive disorders, were eligible if they usedthe term "overdiagnosis" in the title, abstract, or text.

RESULTS

We identified 164 eligible articles with 193 total explicit or implicit uses of the term "overdiagnosis." Of 9 articles with an explicit definition, only one provided a definition that was partially consistent with accepted definitions. Of all uses, 11.4% were consistent, and 76.7% were related to misdiagnosis and thus inconsistent. No attempts to quantify the proportion of patients who were overdiagnosed based on overdetection or overdefinition were identified.

CONCLUSIONS

There are few examples of mental health articles that describe overdiagnosis consistent with accepted definitions and no examples of quantifying overdiagnosis based on these definitions. A definition of overdiagnosis based on diagnostic criteria that include people with transient or mild symptoms not amenable to treatment (overdefinition) could be used to quantify the extent of overdiagnosis in mental disorders.

Is it really always only the others who are to blame? GP's view on medical overuse. A questionnaire study

BACKGROUND

Medical overuse is a common problem in health care. Preventing unnecessary medicine is one of the main tasks of General Practice, so called quaternary prevention. We aimed to capture the current opinion of German General Practitioners (GPs) to medical overuse.

METHODS

A quantitative online study was conducted. The questionnaire was developed based on a qualitative study and literature search. GPs were asked to estimate prevalence of medical overuse as well as to evaluate drivers and solutions of medical overuse. GPs in Bavaria were recruited via email (750 addresses). A descriptive data analysis was performed. Additionally the association between doctors' attitudes and (1) demographic variables and (2) interest in campaigns against medical overuse was assessed.

RESULTS

Response rate was 18%. The mean age was 54 years, 79% were male and 68% have worked as GP longer than 15 years. Around 38% of medical services were considered as medical overuse and nearly half of the GPs (47%) judged medical overuse to be the more important problem than medical underuse. Main drivers were seen in "patients´ expectations" (76%), "lack of a primary care system" (61%) and "defensive medicine" (53%), whereas "disregard of evidence/guidelines" (15%) and "economic pressure on the side of the doctor" (13%) were not weighted as important causes. Demographic variables did not have an important impact on GPs´ response pattern. GPs interested in campaigns like "Choosing Wisely" showed a higher awareness for medical overuse, although these campaigns were only known by 50% of the respondents.

DISCUSSION

Medical overuse is an important issue for GPs. Main drivers were searched and found outside their own sphere of responsibility. Campaigns as "Choosing Wisely" seem to have a positive effect on GPs attitude, but knowledge is still limited.

Measures to Improve Diagnostic Safety in Clinical Practice

Timely and accurate diagnosis is foundational to good clinical practice and an essential first step to achieving optimal patient outcomes. However, a recent Institute of Medicine report concluded that most of us will experience at least one diagnostic error in our lifetime. The report argues for efforts to improve the reliability of the diagnostic process through better measurement of diagnostic performance. The diagnostic process is a dynamic team-based activity that involves uncertainty, plays out over time, and requires effective communication and collaboration among multiple clinicians, diagnostic services, and the patient. Thus, it poses special challenges for measurement. In this paper, we discuss how the need to develop measures to improve diagnostic performance could move forward at a time when the scientific foundation needed to inform measurement is still evolving. We highlight challenges and opportunities for developing potential measures of "diagnostic safety" related to clinical diagnostic errors and associated preventable diagnostic harm. In doing so, we propose a starter set of measurement concepts for initial consideration that seem reasonably related to diagnostic safety and call for these to be studied and further refined. This would enable safe diagnosis to become an organizational priority and facilitate quality improvement. Health-care systems should consider measurement and evaluation of diagnostic performance as essential to timely and accurate diagnosis and to the reduction of preventable diagnostic harm.

"I Did Not Believe You Could Get Better"-Reversal of Diabetes Risk Through Dietary Changes in Older Persons with Prediabetes in Region Stockholm

Diabetes risk can be controlled and even reversed by making dietary changes. The aim of this study was to improve the understanding of how older persons with a high risk of developing Type 2 diabetes manage and relate to information about diabetes risk over a ten-year period. Fifteen qualitative interviews were conducted among participants from the Stockholm Diabetes Prevention Program (SDPP). The participants were asked to recall the health examinations conducted by the SDPP related to their prediabetes and to describe their experiences and potential changes related to diet and physical activity. Data were analyzed using qualitative content analysis. The main theme found was that T2D (type 2 diabetes) risk is not perceived as concrete enough to motivate lifestyle modifications, such as changing dietary patterns, without other external triggers. Diagnosis was recognized as a reason to modify diet, and social interactions were found to be important for managing behavior change. Diagnosis was also a contributing factor to lifestyle modification, while prognosis of risk was not associated with efforts to change habits. The results from this study suggest that the potential of reversing prediabetes needs to be highlighted and more clearly defined for older persons to serve as motivators for lifestyle modification.

Too much? Mortality and health service utilisation among Danish children 1999-2016: A register-based study

OBJECTIVES

To describe the temporal development of mortality and health service utilisation defined as in- and outpatient hospital contacts, contacts with general practitioner and specialists, and prescribed dispensed medication among Danish children 0-5 years of age from 1999 to 2016.

DESIGN

Register-based descriptive study.

PARTICIPANTS

All children born in Denmark in the period 1994-2016 followed until 5 years of age.

MAIN OUTCOME MEASURES

Annual incidence rates of mortality and health service utilisation outcomes, and incidence rate ratios compared to the reference calendar year 1999. The new measure of post-discharge mortality is presented.

RESULTS

Post-discharge mortality decreased from 1999 to 2016, IRR2016 = 0.49 (95% CI: 0.36 to 0.66). Total contacts did not change much over time, IRR2016 = 1.02 (1.02 to 1.03), but increased among neonates, IRR2016 = 3.69 (3.63 to 3.75), and decreased among children with chronic disease IRR2016 = 0.94 (0.93 to 0.94). In- and out-patient hospitalisations increased, IRR2016 = 1.26 (1.24-1.27) resp. IRR2016 = 1.62 (1.60-1.63), contacts with medical specialists increased, IRR2016 = 1.43 (1.42 to 1.43), whilst contacts with general practitioner decreased, IRR2016 = 0.91 (0.91 to 0.91). Medication use decreased, IRR2016 = 0.82 (0.82 to 0.82).

CONCLUSIONS

Our measure of post-discharge mortality was halved during the study period indicating improved health. Overall health service utilisation did not change much, but the type of utilisation changed, and the development over time differed between subgroups defined by age and chronic disease status. Our findings call for considerations about the benefit of increased specialisation and increased use of health services among 'healthy' children not suffering from chronic disease.

Back to Basics: Overdiagnosis Is About Unwarranted Diagnosis

Epidemiologic studies of overdiagnosis are challenged by unclear definitions and the absence of unified measures. This spurs great controversies. Etymologically, overdiagnosis means too much diagnosis and stems from the inability to distinguish what is important from what is not. Accordingly, in order to grasp, measure, and handle overdiagnosis, we should revive medicine's original goal and reconnect diagnosis to what matters to professionals and patients: knowledge and suffering, respectively. This will make overdiagnosis easier to define and measure, and eventually less difficult to reduce.

Analysing the ethics of breast cancer overdiagnosis: a pathogenic vulnerability

Breast cancer screening aims to help women by early identification and treatment of cancers that might otherwise be life-threatening. However, breast cancer screening also leads to the detection of some cancers that, if left undetected and untreated, would not have damaged the health of the women concerned. At the time of diagnosis, harmless cancers cannot be identified as non-threatening, therefore women are offered invasive breast cancer treatment. This phenomenon of identifying (and treating) non-harmful cancers is called overdiagnosis. Overdiagnosis is morally problematic as it leads to overall patient harm rather than benefit. Further, breast cancer screening is offered in a context that exaggerates cancer risk and screening benefit, minimises risk of harm and impedes informed choice. These factors combine to create pathogenic vulnerability. That is, breast cancer screening exacerbates rather than reduces women's vulnerability and undermines women's agency. This paper provides an original way of conceptualising agency-supporting responses to the harms of breast cancer overdiagnosis through application of the concept of pathogenic vulnerability.

Getting personal on overdiagnosis: On defining overdiagnosis from the perspective of the individual person

How can overdiagnosis be defined, explained, and estimated on an individual level? The answers to this question are essential for persons to be able to make informed choices and give valid consents for tests. Traditional conceptions of overdiagnosis tend to depend on counterfactual thinking and prophetic abilities as you would have to know what would happen in the future if you did not test now. To avoid this, overdiagnosis can be defined in terms of the chance of diagnosing a person with a disease when this does not avoid or reduce manifest disease. To be able to relate this to 1's own life and deliberation, I argue that we need answers to specific questions such as the following: If I am tested, and the test and subsequent test results are positive, but I am not treated, what is the chance that I would not experience and suffer from manifest disease? A definition of overdiagnosis that aims at providing answers to this question is as follows: Prospectively overdiagnosis (of an individual person) is given by the estimated chance that a person having a positive test result would not experience and suffer from manifest disease if not treated or followed up in any way. Getting personal on overdiagnosis directs the attention of overdiagnosis estimates towards what matters in medicine: the experience of individual persons.

Is an indistinct picture "exactly what we need"? Objectivity, accuracy, and harm in imaging for cancer

Assumptions about the epistemic ideal of objectivity, closely related to ontological assumptions about the nature of disease as pathophysiological abnormality, lead us into oversimplified ways of thinking about medical imaging. This is illustrated by current controversies in the early detection of cancer. Improvements in the technical quality of imaging failed to address the problem of overdiagnosis in breast cancer screening and exacerbate the problem in thyroid cancer diagnosis. Drawing on Douglas and on Daston and Galison, I distinguish 3 dimensions of objectivity (accuracy, reliability, and precision) and demonstrate ways they may be at odds, as illustrated in the early detection of cancer. Guidelines for evaluating the efficacy of diagnostic imaging are insufficiently sensitive to this complexity. Improving imaging quality may raise epistemic issues, place disease definitions in question, and lead to overall harm or to changes in the distribution of harms and benefits among population subgroups. With a nod to Wittgenstein, I argue that we cannot take for granted that "an indistinct picture" is not "exactly what we need."

Précising definitions as a way to combat overdiagnosis

Roughly, overdiagnosis (ODx) occurs when people are harmed by receiving diagnoses (often accompanied by interventions) that do not benefit them, usually because the diagnosed conditions do not pose a threat to their health. ODx is a theoretical as well as a practical problem as it relates to definitions of disease. Elsewhere, it has been argued that disease is a vague concept and that this vagueness may contribute to ODx. In response, we develop a stipulative or précising definition of disease, for the specific purpose of decreasing or preventing ODx. We call this disease_ODx , aimed at distinguishing cases where it would be beneficial to identify (and treat the condition) from those where diagnosis is more likely to harm than benefit. A preliminary definition of disease_ODx is that X is a disease_ODx iff there is dysfunction that has a significant risk of causing severe harm. This paper examines the 3 concepts in this definition, using a naturalistic account of function, a Feinbergian account of comparative harm, and a probabilistic understanding of risk. We then test the utility of this approach using examples of clinical conditions that are currently overdiagnosed.

Explaining variations in test ordering in primary care: protocol for a realist review

INTRODUCTION

Studies have demonstrated the existence of significant variation in test-ordering patterns in both primary and secondary care, for a wide variety of tests and across many health systems. Inconsistent practice could be explained by differing degrees of underuse and overuse of tests for diagnosis or monitoring. Underuse of appropriate tests may result in delayed or missed diagnoses; overuse may be an early step that can trigger a cascade of unnecessary intervention, as well as being a source of harm in itself.

METHODS AND ANALYSIS

This realist review will seek to improve our understanding of how and why variation in laboratory test ordering comes about. A realist review is a theory-driven systematic review informed by a realist philosophy of science, seeking to produce useful theory that explains observed outcomes, in terms of relationships between important contexts and generative mechanisms.An initial explanatory theory will be developed in consultation with a stakeholder group and this 'programme theory' will be tested and refined against available secondary evidence, gathered via an iterative and purposive search process. This data will be analysed and synthesised according to realist principles, to produce a refined 'programme theory', explaining the contexts in which primary care doctors fail to order 'necessary' tests and/or order 'unnecessary' tests, and the mechanisms underlying these decisions.

ETHICS AND DISSEMINATION

Ethical approval is not required for this review. A complete and transparent report will be produced in line with the RAMESES standards. The theory developed will be used to inform recommendations for the development of interventions designed to minimise 'inappropriate' testing. Our dissemination strategy will be informed by our stakeholders. A variety of outputs will be tailored to ensure relevance to policy-makers, primary care and pathology practitioners, and patients.

PROSPERO REGISTRATION NUMBER

CRD42018091986.

On the Social Construction of Overdiagnosis Comment on "Medicalisation and Overdiagnosis: What Society Does to Medicine"

In an interesting article Wieteke van Dijk and colleagues argue that societal developments and values influence the practice of medicine, and thus can result in both medicalisation and overdiagnosis. They provide a convincing argument that overdiagnosis emerges in a social context and that it has socially constructed implications. However, they fail to show that overdiagnosis per se is socially constructed and how this construction occurs. Moreover, the authors discuss overdiagnosis on a micro level without acknowledging that overdiagnosis cannot be observed in individuals "in the doctor’s office." We cannot tell whether a diagnosed person is overdiagnosed or not. This is the core of the problem. Despite these shortcomings, Wieteke van Dijk and her colleagues are certainly on to something important, and they should be encouraged to elaborate their perspective. We certainly need to deepen our understanding of the social construction of overdiagnosis.

Defining disease in the context of overdiagnosis

Recently, concerns have been raised about the phenomenon of 'overdiagnosis', the diagnosis of a condition that is not causing harm, and will not come to cause harm. Along with practical, ethical, and scientific questions, overdiagnosis raises questions about our concept of disease. In this paper, we analyse overdiagnosis as an epistemic problem and show how it challenges many existing accounts of disease. In particular, it raises questions about conceptual links drawn between disease and dysfunction, harm, and risk. We argue that 'disease' should be considered a vague concept with a non-classical structure. On this view, overdiagnosed cases are 'borderline' cases of disease, falling in the zone between cases that are clearly disease, and cases that are clearly not disease. We then develop a précising definition of disease designed to provide practical help in preventing and limiting overdiagnosis. We argue that for this purpose, we can define disease as dysfunction that has a significant risk of causing severe harm to the patient.

Medicalisation and Overdiagnosis: What Society Does to Medicine

The concept of overdiagnosis is a dominant topic in medical literature and discussions. In research that targets overdiagnosis, medicalisation is often presented as the societal and individual burden of unnecessary medical expansion. In this way, the focus lies on the influence of medicine on society, neglecting the possible influence of society on medicine. In this perspective, we aim to provide a novel insight into the influence of society and the societal context on medicine, in particularly with regard to medicalisation and overdiagnosis.

A definition and ethical evaluation of overdiagnosis

Overdiagnosis is an emerging problem in health policy and practice: we address its definition and ethical implications. We argue that the definition of overdiagnosis should be expressed at the level of populations. Consider a condition prevalent in a population, customarily labelled with diagnosis A. We propose that overdiagnosis is occurring in respect of that condition in that population when (1) the condition is being identified and labelled with diagnosis A in that population (consequent interventions may also be offered); (2) this identification and labelling would be accepted as correct in a relevant professional community; but (3) the resulting label and/or intervention carries an unfavourable balance between benefits and harms. We identify challenges in determining and weighting relevant harms, then propose three central ethical considerations in overdiagnosis: the extent of harm done, whether harm is avoidable and whether the primary goal of the actor/s concerned is to benefit themselves or the patient, citizen or society. This distinguishes predatory (avoidable, self-benefiting), misdirected (avoidable, other-benefiting) and tragic (unavoidable, other-benefiting) overdiagnosis; the degree of harm moderates the justifiability of each type. We end with four normative challenges: (1) methods for adjudicating between professional standards and identifying relevant harms and benefits should be procedurally just; (2) individuals, organisations and states are differently responsible for addressing overdiagnosis; (3) overdiagnosis is a matter for distributive justice: the burdens of both overdiagnosis and its prevention could fall on the least-well-off; and (4) communicating about overdiagnosis risks harming those unaware that they may have been overdiagnosed. These challenges will need to be addressed as the field develops.

Getting clearer on overdiagnosis

Overdiagnosis refers to diagnosis that does not benefit patients because the diagnosed condition is not a harmful disease in those individuals. Overdiagnosis has been identified as a problem in cancer screening, diseases such as chronic kidney disease and diabetes, and a range of mental illnesses including depression and attention deficit hyperactivity disorder. In this paper, we describe overdiagnosis, investigate reasons why it occurs, and propose two different types. Misclassification overdiagnosis arises because the diagnostic threshold for the disease in question has been set at a level where many people without harmful disease are nonetheless diagnosed. We illustrate misclassification overdiagnosis using the example of chronic kidney disease. Misclassification occurs in diseases diagnosed using biomarkers or based on patient reported phenomena. Maldetection overdiagnosis arises because, at the time the diagnosis is made and despite the presence of a 'gold standard' diagnostic test, it is not possible to discriminate between harmful and non-harmful cases of the index disease. We illustrate maldetection overdiagnosis using the example of thyroid cancer. While there is some overlap between misclassification and maldetection overdiagnosis, this conceptual analysis helps to clarify the phenomenon of overdiagnosis and is a necessary first step in developing strategies to address the problem.

Medicalization and overdiagnosis: different but alike

Medicalization is frequently defined as a process by which some non-medical aspects of human life become to be considered as medical problems. Overdiagnosis, on the other hand, is most often defined as diagnosing a biomedical condition that in the absence of testing would not cause symptoms or death in the person's lifetime. Medicalization and overdiagnosis are related concepts as both expand the extension of the concept of disease. They are both often used normatively to critique unwarranted or contested expansion of medicine and to address health services that are considered to be unnecessary, futile, or even harmful. However, there are important differences between the concepts, as not all cases of overdiagnosis are medicalizations and not all cases of medicalizations are overdiagnosis. The objective of this article is to clarify the differences between medicalization and overdiagnosis. It will demonstrate how the subject matter of medicalization traditionally has been non-medical (social or cultural everyday life) phenomena, while the subject matter of overdiagnosis has been biological or biomolecular conditions or processes acknowledged being potentially harmful. They also refer to different types of uncertainty: medicalization is concerned with indeterminacy, while overdiagnosis is concerned with lack of prognostic knowledge. Medicalization is dealing with sickness (sick role) while overdiagnosis with disease. Despite these differences, medicalization and overdiagnosis are becoming more alike. Medicalization is expanding, encompassing the more "technical" aspects of overdiagnosis, while overdiagnosis is becoming more ideologized. Moreover, with new trends in modern medicine, such as P4 (preventive, predictive, personal, and participatory) medicine, medicalization will become all-encompassing, while overdiagnosis more or less may dissolve. In the end they may converge in some total "iatrogenization." In doing so, the concepts may lose their precision and critical sting.

The Rotterdam Study: 2016 objectives and design update

The Rotterdam Study is a prospective cohort study ongoing since 1990 in the city of Rotterdam in The Netherlands. The study targets cardiovascular, endocrine, hepatic, neurological, ophthalmic, psychiatric, dermatological, otolaryngological, locomotor, and respiratory diseases. As of 2008, 14,926 subjects aged 45 years or over comprise the Rotterdam Study cohort. The findings of the Rotterdam Study have been presented in over 1200 research articles and reports (see www.erasmus-epidemiology.nl/rotterdamstudy ). This article gives the rationale of the study and its design. It also presents a summary of the major findings and an update of the objectives and methods.

Wind turbines and health: An examination of a proposed case definition

Renewable energy demands have increased the need for new wind farms. In turn, concerns have been raised about potential adverse health effects on nearby residents. A case definition has been proposed to diagnose "Adverse Health Effects in the Environs of Industrial Wind Turbines" (AHE/IWT); initially in 2011 and then with an update in 2014. The authors invited commentary and in turn, we assessed its scientific merits by quantitatively evaluating its proposed application. We used binomial coefficients to quantitatively assess the potential of obtaining a diagnosis of AHE/IWT. We also reviewed the methodology and process of the development of the case definition by contrasting it with guidelines on case definition criteria of the USA Institute of Medicine. The case definition allows at least 3,264 and up to 400,000 possibilities for meeting second- and third-order criteria, once the limited first-order criteria are met. IOM guidelines for clinical case definitions were not followed. The case definition has virtually no specificity and lacks scientific support from peer-reviewed literature. If applied as proposed, its application will lead to substantial potential for false-positive assessments and missed diagnoses. Virtually any new illness that develops or any prevalent illness that worsens after the installation of wind turbines within 10 km of a residence could be considered AHE/IWT if the patient feels better away from home. The use of this case definition in the absence of a thorough medical evaluation with appropriate diagnostic studies poses risks to patients in that treatable disorders would be overlooked. The case definition has significant potential to mislead patients and its use cannot be recommended for application in any health-care or decision-making setting.

The challenges in defining and measuring diagnostic error

Diagnostic errors have emerged as a serious patient safety problem but they are hard to detect and complex to define. At the research summit of the 2013 Diagnostic Error in Medicine 6th International Conference, we convened a multidisciplinary expert panel to discuss challenges in defining and measuring diagnostic errors in real-world settings. In this paper, we synthesize these discussions and outline key research challenges in operationalizing the definition and measurement of diagnostic error. Some of these challenges include 1) difficulties in determining error when the disease or diagnosis is evolving over time and in different care settings, 2) accounting for a balance between underdiagnosis and overaggressive diagnostic pursuits, and 3) determining disease diagnosis likelihood and severity in hindsight. We also build on these discussions to describe how some of these challenges can be addressed while conducting research on measuring diagnostic error.