Errors and adverse events in dentistry – a review

The difference between an error and a violation

An error is defined as an inadvertent divergence from your intended course of action,¹ whereas faults or violations are defined as a deliberate deviation from the guidelines and rules of a given system.¹

Whilst we accept that every clinician may commit an error, we assume that, as responsible clinicians, we would never consider deliberately deviating from the guidelines. However, although there are no papers relating directly to dentistry, there is a body of evidence suggesting that 30% of those in the medical profession possess attitudes that represent a danger to the safety of their patient.⁵ In particular macho, anti-authority, impulsive and invulnerability.⁵

Why do we make errors?

As clinicians, we are not simply fixing a problem, we are treating a patient. We typically want to do our best and provide a high standard of care. Despite this, we can underestimate the risk of complications during our initial assessment.⁶ This is likely due to dentists adopting an empathetic approach rather than an analytic approach. This, combined with 75–90% of dentists thinking that they are smarter or more skillful than the others,⁶ creates a feeling of security and invincibility.

Frequency and aetiology of error

Errors are inextricably linked to human behaviour.^{7,8,9,10,11,12,13,14,15} The first and significant step in the process of changing our attitude to error is to acknowledge that errors will happen and to try to establish the level of risk of error associated with specific types of performance in dentistry.

Errors are not associated with fault or punishment, however, we need to analyse the cause of error in order to help prevent errors occurring and improve patient safety. The International Classification for Patient Safety (ICPS) 2009 aims to strengthen science-based systems, and identify and define key concepts in order to improve patient safety.¹⁶

This need has directed a body of research to develop strategies for a ‘patient safety culture’,¹⁷ including the use of clinical audit,¹⁸ safety checklists,¹⁹ reporting of errors,^20,21 a national database of errors,^20,22 the NHS publishing ‘Never Events List’, including wrong site surgery and wrong tooth extraction,²³ a call to action to develop a patient safety initiative,²⁴ the development of a novel trigger tool to detect adverse events in patients' charts,²⁵ a study on the dangers of dental devices,²⁶ and studies investigating the aetiology of error.²⁷

Despite clinical audit being a widely adopted tool for analysing practice and identifying errors, to the best of our knowledge there is little research in dentistry on the causes and frequency of error in day-to-day practice, thus little is understood about the role of human factors and their likely risk of causing adverse events.

A recent investigation sought to establish, for the first time, an insight into the risk factors likely to contribute to errors and if there is a link between risk of error and perceived cause of an adverse event in dental practice. This study found that the perceived mean number of errors that occur each day is 2.016, ranging from a minimum of 1 and maximum of 4. The number of errors was unrelated to the number of years qualified and number of sessions worked each week. Importantly, the same study found that, on average, 1.45% of errors are perceived to lead to an adverse event (ranging from a minimum of 0 and maximum of 6.)

Kalenderian et al²⁵ looked retrospectively at patient charts and notes, and identified 34% of randomly selected case notes, and 50% of case notes that ‘triggered’ predefined characteristics contained at least one adverse event. However, as far as we are aware, there are no other studies that investigate the frequency that errors occur within dentistry. One study has investigated the percentage of patient contacts where errors occur. A total of 1000 patients' notes were assessed and they found 46 errors, of which 18 were preventable.¹ However, they noted that the poor record-keeping may have resulted in an underestimation of the result.

Wetzel et al identified stress as a major contributory factor negatively affecting surgical performance.²⁸ They cite emergency cases, unexpected complications, equipment problems, team work problems, distractions, personal factors and problems having major effects on the frequency and severity of error. They also state that these stresses are accumulative and therefore managing these is essential for patient safety.

Preventing error

The role of human factors in healthcare is concerned with ensuring patient safety through promoting efficiency, safety and effectiveness by improving the design of technologies, processes and work systems.²⁹ Essentially, it embraces standardization and involves examining and designing out error.

Despite the National Quality Board forming the ‘Human Factors in Healthcare Concordat’, Health Education England highlighting education in Human Factors as a priority workstream, and US Department of Health and Human Services Agency for Healthcare Research and Quality (AHRQ) driving forward the agenda for quality and patient safety,³⁰ there are many impediments to progress as system changes are slow and difficult to implement.³¹ This effectively means that, at present, it is up to individual practitioners to introduce the concept of human factors into their practices.

A number of factors have been identified that are critical to reducing error, namely teamwork,³² communication,³³ leadership³⁴ and fatigue.³⁵

The understanding of the link between the significant cause of error and human performance in healthcare is improving, however, when compared to other organizations, dental practitioners still have much to learn.³⁶ In order for this to happen, it is necessary to raise awareness of human factors and the benefit that training in human factors can bring to our practising life and to the safety of our patients.

There is awareness that we need to minimize error in healthcare. However, almost all of this relates to the secondary care sector, where it is recognized that effective leadership,¹⁹ specific policy and procedure,³⁷ and monitoring and measuring compliance, leads to a strong patient safety culture.¹⁹ However, there is no evidence that this level of rigour is prevalent in primary care.

There is a body of literature which offers advice to the primary care practitioner of how errors relating to human factors can be minimized. Pemberton suggests four strategies:

The General Medical Council commissioned a study in 2009 to investigate errors in trainee doctors and consultants. They investigated prescribing errors and concluded that 1 in 10 prescriptions were incorrect for junior doctors, and 1 in 20 were incorrect for consultants.³⁸ A literature review concluded that 2700 patients each year are harmed by wrong site surgery, and highlighted that understanding the nature of errors and that of human factors is key in creating a just culture that encourages a shared vision of patient safety.³⁹

Several studies demonstrate that fatigue and working long hours affect judgement, behaviour and the likelihood of a professional to make an error,⁴⁰ and there are many tools, eg FAST (Fatigue Avoidance Scheduling Tool)⁴¹ to educate and reduce the effects of fatigue. These studies are largely subjective and there are no studies that directly relate working hours to the number of errors that are made in dentistry.

The progression of error to an adverse event

An error in itself does not necessarily lead to complications, however, safety margins are reduced, making the likelihood of an error leading to an adverse event more likely. The number of errors that lead to an ‘adverse event’ was perceived to be 1.4%. There are a number of models that discuss how we can avoid this progression from an error to a more significant complication. It is usually the result of multiple system failures, as described initially by the ‘Swiss Cheese Model’,⁴² and more recently by Eindhoven's Classification of Errors and the PRISMA (Prevention and Recovery Information System for Monitoring and Analysis).⁴³

There are few studies, however, that investigate the frequency or incidence of this progression, and additionally none that relates specifically to dentistry. A multi-centred study investigated errors in psychiatry and concluded that most errors are insignificant, however, 4.3% result in serious adverse effects or death.⁴⁴ A further paper described, significantly, that 1.7% of prescribing errors by doctors were potentially fatal.³⁸ A study by the authors of this paper found that the main reason why we commit errors is due to time pressures, closely followed by poor management, implicating ‘the system’ in the aetiology of error. This is consistent with research in other areas of medicine, where studies have shown that up to 69% of complications were caused by avoidable (cognitive) human factor error,⁴⁵ citing time pressure as the major cause.³⁷

Strategies for avoiding error are best described in the literature relating to aviation, and many of these principles are now starting to be reported in the medical literature. Strategies such as checklists,⁴⁶ crew resource management (CRM)⁴⁷ and teamwork⁴⁷ have been translated to dentistry in the form of checklists,¹⁹ audit cycles,³⁵ clinical effectiveness dashboards,³⁵ and prospective and retrospective risk analysis.⁴⁸

Implications for practice

The majority of the causes of error are related to human factors rather than technical ability or inadequate knowledge. This has major implications for primary care practice, as currently we are concentrating our professional development on the use of technology and our intellectual capabilities, rather than learning from the hospital setting in secondary care, or other high risk organizations, such as aviation, and implementing education from within with the development of ‘human factors’. Furthermore, based on this review, we should have strategies in place to help reduce errors due to human factors (Table 1). It is our recommendation that ‘human factors’ form part of our undergraduate teaching and core CPD (Continued Professional Development).

Implications for research

There needs to be a paradigm shift from a culture of blame to a just culture, where it is accepted that, despite our experience, character and talents, we are going to commit errors. This way errors can be reported, analysed and preventive measures taken.

We need further research to understand the causes of error within Dentistry, and to create a ‘fair blame’ reporting system for adverse events. This can then be made available to the profession for analysis and to establish approaches that minimize error and improve patient safety.