What is Overdiagnosis?  – Is this the same as ‘Too much medicine’

Overdiagnosis occurs when individuals are diagnosed with conditions that will never cause symptoms or death [Ref]. More broadly overdiagnosis refers to the related problems of overmedicalisation and subsequent overtreatment, diagnosis creep, shifting thresholds, and disease mongering, all processes helping to reclassify healthy people with mild problems or at low risk as sick [Ref].

Most doctors believe medicine to be a force for good. Why else would they have become doctors? Yet all know medicine’s power to harm individual patients and whole populations. Few would agree with Ivan Illich that “The medical establishment has become a major threat to health.” Many might, however, accept the concept of the health economist Alain Enthoven that increasing medical inputs will at some point become counterproductive and produce more harm than good. So where is that point, and might we have reached it already? [BMJ editorial –Ref ]

In 2011, the cost of overtreatment in the US is estimated between $158 to $226 billion [Ref].  The average expenditures for each false-positive mammogram, invasive breast cancer, and ductal carcinoma in situ in the twelve months following diagnosis were $852, $51,837 and $12,369, respectively. This translates to a national cost of $4 billion each year. [Ref]

There is much to discuss: how should we define overdiagnosis and its ugly siblings overtreatment, medicalisation, and disease mongering; what do we know of their causes; and what evidence based solutions are available, both general and specific? Above all, who gets to judge when care is inappropriate in any individual case? [Ref – Godlee BMJ]

What is not Overdiagnosis?

Overdiagnosis is not a false-positive result of a diagnostic test [Ref ] . False positives are abnormalities that turn out not to be a disease after further investigations. For example if a woman undergoes a mammography screening and a abnormality is detected. A lumpectomy or mastectomy is done, but the removed tissue does not show a malignancy. This is know as a false positive. This woman was not subjected to overdiagnosis but certainly she was overtreated.

Overdiagnosis is not the same as Overtreatment, whether unnecessary or overaggressive. Overdiagnosis typically leads to overtreatment, but not always. However, overtreatment can occur without overdiagnosis.  Examples are middle ear infections in children and bronchitis in adults are correctly diagnosed but overtreated with ineffective antibiotics. Distinguishing overtreatment caused by lack of the knowledge of the current evidence from overtreatment caused by overdiagnosis.

Overdiagnosis is not synonymous with overtesting, sometimes referred to as overuse or overutilization. However overtesting can increase the risk of overdiagnosis, but the risk increased with the proportion of overuse.

Overdiagnosis is not misdiagnosis, but sometimes this is not clearcut. For example, a boy who cannot focus in class and exhibits disruptive behaviour may be diagnosed to have ADHD. However he turns out to have dyslexia, and not ADHD. Not so clear cut issues happens in cancer, overdiagnosed cancer could be considered a misdiagnosis of progressive cancer that requires treatment. Cancer pathology at the time of diagnosis is just a snapshot, it cannot perfectly distinguish the clinically relevant from the overdiagnosed cancers (eg, one Gleason grade prostate cancer might be destined to progress while another of the same grade is not). If new biomarkers, genes or antibodies could perfectly distinguish neoplastic pathology, a diagnosis of ‘cancer’ not destined to progress could be considered to be a misdiagnosis, rather than an overdiagnosis.


Why is overdiagnosis important even in low and middle income countries?

 Anita Jain from BMJ India [Ref] recalls a talk from a respected clinician on the first day of clinical medicine rotation as a medical student.  “A barber does greater service to society than you ever will as a doctor,” he said emphatically. “You are here to make money.”  Some doctors take a cut from investigations and drugs prescribed to stay in business . Compelled to reach a diagnosis, using a battery of tests. This is accompanied by increased screening for diseases, cancer, follow-up test. Repeating test because of unreliability of tests and the uncontrolled laboratories. e.g. Malaria is treated in-spite of blood film negative because doctors cannot trust the labs. Throughout the clinical training doctors are taught, almost compelled to reach a ‘diagnosis’, which got the accolades from the professors. This reflects a disconnection from actual practice where uncertainty if the norm.

‘Unique dimension of overdiagnosis in low and middle income countries is presented by extrapolation to the local context of guidelines derived from research in higher income countries.’ CHDR – India malnutrition is 25%? WHO basing the cut-off on developed country data? – opportunity to promote milk products and biscuits among children. overdiagnosis of thyroid cancer in Korea. Cardiologist in India less investigate?. Engaging with patients is a must. With short consultation time especially channelling? Fixed cost investigations and quality assurance.

Not all agree that overdiagnosis is important. Harvard professor Koplan is quoted as stating that “Overdiagnosis is a myth that has been created by a handful of individuals who provide no care for women with breast cancer.” [Ref]

McCormack’s latest, Bridge Over Diagnosis, may well prove as popular, offering an entertaining way to educate and inform about this complex and often counterintuitive problem, all set to the soundtrack of Simon and Garfunkel’s classic hit record (https://www.youtube.com/watch? v=gfesuNG0-kQ).

Drivers of overdiagnosis



Communicating overdiagnosis

Ref – PubMed

Communication that empowers the public, patients, clinicians, and policy makers to think differently about overdiagnosis will help support a more sustainable healthcare future for all

Understanding of overdiagnosis among the general public and health professionals is limited, so it is essential to communicate what it means for individuals, the health system, and society.

By definition, overdiagnosis will not improve prognosis and will probably harm individuals (for example, by unnecessary intervention) or society (opportunity costs). For individuals, it is important to communicate the nature (physical or psychological), likelihood, and duration of the harms. For societies with free public healthcare, the financial strain and opportunity cost are usually at system level—resources wasted on unnecessary tests and treatments are unavailable for people in greater need. But in private healthcare systems, overdiagnosis can be a huge personal financial burden, even for those with insurance.

Strategies for the individual

Shared decision making is a consultation process where a clinician and patient jointly make a health decision. It changes the way decisions are framed by identifying that there is a decision to be made (not an obligatory test or default treatment), and explaining the range of options available and their benefits and harms. It also involves deciding with patients “what is most important to them” in terms of their values, preferences, and circumstances.4 Importantly, the option of doing nothing or active surveillance can be discussed as a deliberate or positive action5 to counter people’s bias for tests and treatment, especially in cancer.6

Patient decision aids support shared decision making. High quality evidence from 115 trials shows that they improve patients’ knowledge and understanding of options and their risks and benefits, and increase consistency between patients’ values and choices.9 Decision aids have successfully informed women about overdiagnosis in breast screening,3 reduced men’s desire for prostate specific antigen (PSA) testing10 or surgical management for prostate cancer, and reduced preferences for potentially unnecessary elective surgery.

Strategies for communities

Mass media and direct to consumer campaigns can influence large numbers of people simultaneously and promote sustained beneficial changes in behaviour.16 For example, a mass media campaign about back pain,

Other important initiatives include the Choosing Wisely campaign, now operating in nine countries (www. choosingwisely.org), and the UK’s “do not do” list

Policy directed strategies

Deliberative democratic methods (such as community juries) support policy decisions by gathering informed public responses about disputed issues, such as what services are available or reimbursed by health funds. Because overdiagnosis is scientifically and politically contested, this topic is ideal for deliberative democratic methods. Deliberative methods must meet exacting standards and are time consuming.18 Community juries have considered PSA testing in Australia19 20 and mammographic screening in New Zealand, where participants changed their recommendation at least partly because of potential harms from overdiagnosis.21 Disseminating findings from juries could enhance community health literacy, leading to better informed citizens and more transparent decision making.

Changing terminology: Behaviours can be influenced by medical terminology, and changing the names for medical conditions may help reduce the effect of overdiagnosis. In one study, describing ductal carcinoma in situ as “non-invasive cancer” resulted in 13-16% more women choosing surgical treatment (rather than medication or active surveillance) compared with calling it a “breast lesion” or “abnormal cells.”22 Similar findings were reported in Australia.23 24 Independent experts convened by the US National Cancer Institute25 and National Institute of Health have proposed dropping the word “cancer” entirely in this case, arguing for it to be reserved for lesions likely to progress if untreated.25 26 Similar arguments exist for thyroid and prostate cancer,27 but effects of disease labels extend beyond cancer.

Potential challenges to effective communication

Low levels of awareness: Awareness of overdiagnosis is low, particularly for cancer screening with few people understanding overdiagnosis of cancer is even possible.29

Cognitive biases and counterintuitive messages: Longstanding, prominent public health messages have emphasised the benefits and ignored the harms of early diagnosis for many diseases.36 37 This makes the concept of overdiagnosis unfamiliar, counterintuitive, and difficult to understand.

Cognitive biases and counterintuitive messages: Longstanding, prominent public health messages have emphasised the benefits and ignored the harms of early diagnosis for many diseases.36 37 This makes the concept of overdiagnosis unfamiliar, counterintuitive, and difficult to understand.

Vested interests and persuasive communication: Vested interests may influence how information is presented in the media and the scientific arena. Pharmaceutical and device manufacturers

Overdiagnosis, Ethics and trolley problems [Ref Stacy Carter USyd ]

‘In February 2014, the non-governmental Swiss Medical Board recommended that mammography programmes in Switzerland may eventually be closed down because they might not deliver more benefits than harms. In the resulting uproar the board was accused of being “unethical.” (Ref Link ) [Committee appointed consists of 6 different specialities). Ref gives an historical facts of BCS from early 1990

‘Controversy about mammography has persisted in the UK,2 US,3 Canada, and elsewhere,4 and disputes about overdiagnosis exist in prostate cancer,5 chronic kidney disease,6 attention-deficit/hyperactivity disorder (ADHD),7 and many other conditions. People concerned about overdiagnosis are compelled by evidence of harms outweighing benefits. But not everyone is equally compelled. This may be because of disagreements over the evidence,8 conflicts of interest,9 10 or cognitive biases.11 Another possible cause of disagreement is that some people may not think that benefits and harms are the most important consideration.’

Two classic trolley problems are “switch” and “bridge.”

In the switch problem, a trolley (tram) is hurtling down a track. Five workers are on the main track. One worker is on a branch track. If the trolley continues, it will kill the five workers. A switch will divert the trolley onto the side track, and it will kill one worker.14 15 Should you throw the switch?

In the bridge problem, five workers are on the track. A large, heavy person stands on a bridge. If you push the person off the bridge and onto the track it will stop the trolley. The large person will die; the five will live.14 15 Should you push the person?

In empirical studies of ordinary people, however, responses to the two scenarios differ. About 90% of people say it is acceptable to throw the switch,16 17 whereas only 10% of people are comfortable with pushing the person.16

Reactions are generally even stronger to a medical example known as “transplant.” A skilled transplant surgeon has five patients who will die without immediate transplantation, each of a different organ. A passerby happens to be a perfect donor for all five patients. Should the surgeon anaesthetise the passerby and transplant their organs, saving the five but killing the donor? Almost everyone says no emphatically,20 even though it results in one dead person and five survivors, just as in “switch.”

Theoretical and experimental research indicates that framing is important, including the order in which options are presented and the terminology used (for example, “saving” versus “killing”).17 21

People may be less willing to trade lives for lives and more willing to trade injuries or property loss for lives.17 Avoiding harm may seem more important than providing benefit.14-22 Serious outcomes may not be exchangeable for (even many) more trivial outcomes.

Sri Lankan context – out of pocket expenses are increasing and is around 27%

Examples of overdiagnosis with specific examples

The definition of hypertension – SPRINT to lower limits

Recent BMJ article 

The problems with lowering the BP based on just ONE trial – SPRINT why SPRINT may be not methodologically strong [some concerns from the AC Cardiology LINK ]