MEDICALISATION bmj.com � BMJ blog: Elizabeth Loder on tackling unnecessary treatment in the US: This time “it feels diff erent” � Des Spence: The psychiatric oligarchs who medicalise normality (BMJ 2012;344:e3135) � Research: Overdiagnosis in publicly organised mammography screening programmes (BMJ 2009;339:b2587) Preventing overdiagnosis: how to stop harming the healthy Evidence is mounting that medicine is harming healthy people through ever earlier detection and ever wider definition of disease. With the announcement of an international conference to improve understanding of the problem of overdiagnosis, Ray Moynihan , Jenny Doust , and David Henry examine its causes and explore solutions edicine’s much hailed ability to help the sick is fast being challenged by its propensity to harm the healthy. A burgeon- ing scientifi c literature is fuel- M ling public concerns that too many people are being overdosed, 1 overtreated, 2 and overdiag- nosed. 3 Screening programmes are detecting early cancers that will never cause symptoms or death, 4 sensitive diagnostic technologies iden- tify “abnormalities” so tiny they will remain benign, 5 while widening disease defi nitions mean people at ever lower risks receive permanent medical labels and lifelong treatments that will fail to benefit many of them. 3 6 With estimates that more than $200bn (£128bn; €160bn) may be wasted on unnecessary treatment every year in the United States,7 the cumulative burden from overdiagnosis poses a signifi cant threat to human health. Narrowly defined , overdiagnosis occurs when people without symptoms are diagnosed with a disease that ultimately will not cause them to experience symptoms or early death.3 More broadly defi ned, overdiagnosis refers to the related problems of overmedicalisation and subsequent overtreatment, diagnosis creep, shift ing thresholds, and disease mongering, all processes helping to reclassify healthy people with mild problems or at low risk as sick. 8 The downsides of overdiagno- Changing diagnostic criteria sis include the negative effects of for many conditions are unnecessary labelling, the harms of unneeded tests and therapies, and the causing virtually the entire opportunity cost of wasted resources that older adult population to be could be better used to treat or prevent classified as having at least genuine illness. The challenge is to articu- one chronic condition BMJ | 2 JUNE 2012 | VOLUME 344 19 MEDICALISATION 5 late the nature and extent of the problem more Thyroid cancer causes. As we will discuss below, there is now widely, identify the patterns and drivers, and New diagnoses strong evidence from randomised trials and other develop a suite of responses from the clinical to Deaths studies comparing screened and unscreened the cultural. populations that an important proportion of the At the clinical level, a key aim is to better dis- cancer detected through some popular screening criminate between benign “abnormalities” and programmes may be pseudodisease.4 12 Evidence those that will go on to cause harm. In terms of Rate per people from autopsy studies suggests a large reservoir education and raising awareness among both the of subclinical disease in the general population, public and professionals, more honest informa- including prostate, breast, and thyroid cancer, Melanoma 12 tion is needed about the risk of overdiagnosis, the bulk of which will never harm. Similarly, particularly related to screening. More deeply, screening the hearts of people without symp- mounting evidence that we’re harming healthy toms or at low risk may also lead to overdiagno- people may force a questioning of our faith in sis of coronary atherosclerosis and subsequent ever-earlier detection, a renewal of the process unnecessary interventions.13 Our understanding of disease definition, and a fundamental shift in of the nature and extent of overdiagnosis and the Rate per people the systemic incentives driving dangerous excess. amount of pseudodisease detected by screening Next year, an international scientific confer- remains limited but is evolving, and as Woolfe ence called Preventing Overdiagnosis aims to and Harris observed recently in JAMA, “concern Kidney cancer deepen understanding and awareness of the e about overdiagnosis is justified.”14 problem and its prevention. The conference will take place on 10-12 September 2013 in Increasingly sensitive tests the United States, hosted by the Dartmouth People presenting to doctors with symptoms can Institute for Health Policy and Clinical Practice also be overdiagnosed because changes in diag- in partnership with the BMJ, the leading US Rate per peopl nostic technologies or methods have enabled the consumer organisation Consumer Reports, and identification of less severe forms of diseases or Bond University. The conference is timely, as disorders. It is becoming clearer that a substan- growing concern about overdiagnosis is giving Prostate cancer tial proportion of these earlier “abnormalities” way to concerted action. The Archives of Internal will never progress, raising awkward questions Medicine’s feature “Less is More” now regularly about exactly when to use diagnostic labels and 9 augments the evidence base, high level health therapeutic approaches traditionally deployed policy groups in Europe are debating ways against much more serious forms of disease. to tackle excess,10 and the recently launched Rate per people Choosing Wisely campaign warns about dozens Incidentalomas of potentially unnecessary tests and treatments Diagnostic scanning of the abdomen, pelvis, across nine specialties.11 chest, head, and neck can reveal “incidental Breast cancer Many factors—including the best of inten- findings” in up to 40% of individuals being tions—are driving overdiagnosis, but a key con- tested for other reasons.15 Some of these are tributor is advances in technology. The literature tumours, and most of these “incidentalomas” suggests several broad and related pathways to are benign. A very small number of people will overdiagnosis: screening detected overdiagno- benefit from early detection of an incidental sis in people without symptoms; overdiagnosis Rate per people malignant tumour, while others will suffer the resulting from use of increasingly sensitive tests anxiety and adverse effects of further investi- in those with symptoms; overdiagnosis made gation and treatment of an “abnormality” that incidentally—“incidentalomas”; and overdiag- Year would never have harmed them. As others have nosis resulting from excessively widened disease Rates of new diagnosis and death for five types of shown, the rapidly rising incidence for some can- cancer in the US, 1975-2005. Adapted from Welch definitions. These different pathways are not 12 cers, set against relatively stable death rates, is a mutually exclusive, and a more rigorous classi- and Black phenomenon suggestive of widespread overdiag- fication of the different forms of overdiagnosis nosis, whether from screening or the detection of will be a focus of discussion at the 2013 scien- form that will never cause that person symptoms incidentalomas (figure).12 tific conference. or early death. Sometimes this form of disease is called pseudodisease. Contrary to popular Excessively widened definitions Screening detected overdiagnosis notions that cancers are universally harmful and Another pathway to overdiagnosis is through dis- This pathway to overdiagnosis occurs when a ultimately fatal, some cancers can regress, fail ease boundaries being widened and treatment screening programme detects disease in a per- to progress, or grow so slowly that they will not thresholds lowered to a point where a medical son without symptoms but the disease is in a cause harm before the individual dies from other label and subsequent therapy may cause people 20 BMJ | 2 JUNE 2012 | VOLUME 344 MEDICALISATION Arguably the strongest evidence of overdiagnosis comes from studies of screening detected breast cancers more harm than good. Changing diagnostic cri- Box 1 | Problems of overdiagnosis Gestational diabetes teria for many conditions are routinely increasing A 2010 revision of the criteria defining gesta- 16 Asthma—Canadian study suggests 30% the numbers of people defined as sick, causing of people with diagnosis may not have tional diabetes recommended a dramatic low- virtually the entire older adult population to be asthma, and 66% of those may not require ering of the diagnostic threshold, more than classified as having at least one chronic condi- medications37 doubling the number of pregnant woman clas- tion.17 This widening has happened both with Attention deficit hyperactivity disorder— sified to almost 18%.29 Proponents argue uni- asymptomatic conditions that carry a risk of an Widened definitions have led to concerns versal screening with the new definition will adverse event, such as osteoporosis, where treat- about overdiagnosis; boys born at the end of the reduce health problems, including babies being ments may do more harm than good for those at school year have 30% higher chance of diagnosis “large for gestational age.”29 Critics, however, and 40% higher chance of medication than those very low risk of fracture,18 and for behavioural are calling for an urgent debate before the new born at the beginning of the year46 conditions such as female sexual dysfunction, expanded definition is more widely adopted, Breast cancer—Systematic review suggests up where common difficulties have been reclassi- because