The Quality Chasm Series by the Institute of Medicine elaborates on why it is important to improve diagnosis in healthcare, “Getting the right diagnosis is a key aspect of healthcare. It provides an explanation of a patient’s health problem and informs subsequent healthcare decisions. For decades, diagnostic errors – inaccurate or delayed diagnosis – have represented a blind spot in the delivery of quality healthcare.

The complexity and plethora of causes of diagnostic errors will suggest that there is no ‘magic bullet’ but a need for a ‘multifaceted’ approach to understand and address the many systems and cognitive issues involved.

Diagnostic errors persist throughout all settings of care and continue to harm an acceptable number of patients.” The WHO, in advocating the need for patient safety areas in primary care, included diagnostic errors as a high-priority problem.


The Institute of Medicine defines it as, ‘the failure to (a) establish an accurate and timely explanation of the patient’s health problem(s) or (b) communicate that explanation to the patient’. This definition is from a patient’s perspective because the ‘patients bear the ultimate harm from diagnostic errors’. There are several sources of diagnostic errors. Amongst these are: inadequate collaboration and communication among clinicians, patients and their families; a healthcare system that is not designed to support diagnostic process; limited feedback to clinicians, a lack of transparency and disclosure of diagnostic errors, ‘which in turn may impede attempts to learn from these events and improve diagnoses.

The complexity and plethora of causes of diagnostic errors will suggest that there is no ‘magic bullet’ but a need for a ‘multifaceted’ approach to understand and address the many systems and cognitive issues involved in diagnostic errors. The contributing causes for high risk areas for errors in primary care practice are due to high patient volumes and they may make decisions amid uncertainty. Often patients present at primary care practices with undifferentiated presenting features, uncommon diseases which can be serious and life-threatening.

The pattern often is a diagnosis that may unfold over time and after a number of episodes of care. The challenge is that primary care practitioners must balance the risk of missing a diagnosis. A diagnostic error occurs when a patient’s diagnosis is missed altogether; inappropriately delayed and/or wrong. It is often hard to distinguish between the three; eg in both missed and wrong scenarios, diagnosis could have been delayed. There often are no clear guidelines for ‘timely’ diagnosis for majority of conditions.

Diagnostic errors may cause harm to patients by preventing or delaying appropriate treatment, providing unnecessary or harmful treatment, or resulting in psychological or financial repercussions. It is estimated that 5% of patients who seek outpatient care each year experience diagnostic errors (IOM). The Quality Chasm series goes on to state that post-mortem examination research spanning decades has shown that diagnostic errors contribute to approximately 10% of patients’ deaths and medical record reviews suggest that they account for 6% to 17% of adverse events in hospitals.

It is stated that diagnostic errors are the leading type of paid medical malpractice claims and are almost twice as likely to have resulted in the patients’ deaths compared to other claims. There are five sources of diagnostic errors:

1. The patient – provider encounter: History, examination, ordering tests / referrals based on appropriate assessment
2. Performance and Interpretation of diagnostic tests
3. Follow up and tracking of diagnostic information over time (such as abnormal tests)
4. Sub-speciality and referral-related communication and coordination issues
5. Patient behaviour, adherence and engagement.

Often more than one dimension is involved in an error. Errors can be described as missed opportunities that could be used to promote learning and improvement versus assigning blame or responsibility to a single clinician. The concept of missed opportunities also implies that something different could be done to prevent the error.

There are three criteria that should be considered when defining diagnostic errors:

1. All errors occur when there is evidence of a missed opportunity to correct or for timely diagnosis. Something different could have been done to make the correct diagnosis earlier
2. The missed opportunity due to the ‘evolving diagnostic’ process – due to the temporal context of events This could imply that there is evidence of omission (failure to do the right thing) or commission (doing something wrong) at the time the ‘error’ occurred
3. The opportunity could be missed by the provider, care team and/or patient.

A preventable error or delay may occur due to factors outside a single physician’s immediate control. These errors may involve some degree of hindsight bias – a bias in judgment about a diagnosis, which can be determined by retrospective knowledge, where warning signs and symptoms are overlooked or are less obvious at the time of the encounter (BMJ, Quality + Safety). Not all missed opportunities are harmful.

The goal is to focus on preventable diagnostic harm, based on the evidence of all types of diagnostic errors. It is important to focus on low- and middle-income countries, where diagnosis poses even greater challenges as the access to healthcare is limited and there are limited diagnostic testing resources. There is also a paucity of qualified primary care providers, sometimes specialists and electronic record keeping.

There appears to be a higher rate of diagnostic errors in low- and middle-income settings compared with high resource settings. It is postulated that the limited access to health professionals, diagnostic tests might lead to under-diagnosis in LMICs, whilst in high resource countries might be prone to over-diagnosis. This may be due to sophisticated imaging and laboratory testing and sub-speciality consultation that are more accessible and the concern about malpractice liability if a diagnosis is missed (BMJ, Quality + Safety).

Common diagnostic errors in primary care practices include cancer, pulmonary embolism and coronary artery disease. In the USA, of the 181 malpractice claims, cancer was the most common diagnosis involved. In an analysis of 1 000 malpractice claims against UK General Practitioners identified diagnostic errors most commonly involving infections, trauma and cancer. In the outpatient settings, infections, cardio-vascular disease and cancer are the most significant categories of harmful diagnostic errors.

As children are frequently seen in primary care and are vulnerable to errors, they are included in the high-risk populations. The Quality Chasm series (IOM) outlined eight goals to reduce diagnostic errors and improve diagnosis:

1. Facilitate more effective teamwork in the diagnostic process among healthcare professionals, patients and their families. The process to make a diagnosis hinges on successful collaboration among healthcare professionals, patients and their families. Patients and families are important partners in the diagnostic process, supported by healthcare professionals. This is the concept of an inclusive informed teamwork in the diagnostic process
2. Enhance Healthcare Professional education and training in the diagnostic process. Increased emphasis on diagnostic competencies and feedback on diagnostic performance are needed
3. Ensure the health information technologies (IT) support patients and healthcare professionals in the diagnostic process. There is a need to better align it with the diagnostic process. Health IT has the potential to improve diagnosis and reduce diagnostic errors. The process needs to be coordinated to avoid it contributing to errors itself
4. Develop and deploy approaches to identify, learn from, and reduce diagnostic errors and near misses in clinical practice. There is a need to collect information, to learn from experiences and to implement changes. This will improve process and improve alertness to avoid errors
5. Establish a work team and culture that supports the diagnostic process and improvements in diagnostic performance. There should be feedback on diagnostic performance, ensure effective communication, in diagnostic testing and design a work system that supports team members involved in diagnostic process, including integrating error recovery mechanisms
6. Develop a reporting environment and medical liability system that facilitates improved diagnosis through learning from diagnostic errors and near misses
7.  Design payment and care delivery environments that support the diagnostic process. Payment methods are likely to influence the diagnostic process and the occurrence of diagnostic errors. For example, the fee for service payment lacks incentives to coordinate care. Research needs to be conducted to understand the impact of payment methods on the care delivery models and on diagnosis
8. Provide dedicated funding for research on the diagnosis process and diagnostic errors.

AUTHOR: Prof Morgan Chetty, visiting Prof: Health Sciences, DUT chairman, IPAF, CEO: KZNDHC


Diagnostic errors are relatively frequent and harmful in primary care. Primary care practices are at the cold front of healthcare and are challenged to isolate the main reason for the consultation notwithstanding the related issues that patients present with. The arrival at a diagnosis should occur after a protracted period of listening and examining the patient. In most times there will be an element of uncertainty. This will need to be investigated or referred appropriately. PCPs need to benefit from working in a blame-free environment.