Half of all harm to patients owing to medical error can be prevented, say researchers

Half of all harm to patients owing to medical error can be prevented, say researchers

Half of all harm that comes to patients as a result of errors during their medical care can be prevented, shows an analysis involving over 330,000 patients in the US and Europe. The study said in 12% of the cases, preventable harm was severe as it led to permanent disability or death.

According to the research, preventable patient harm not only causes public health concerns but also incurs a considerable “opportunity cost.” The excess length of hospital stays owing to medical errors is estimated to be 2.4 million hospital days, which accounts for $9.3 billion excess charges in the US.

The study has been done by a team of medical professionals led by Dr. Maria Panagioti from the NIHR Greater Manchester Patient Safety Translational Research Centre. 

“Patient harm in the process of healthcare is common, but at least half of these harms could be prevented. Although serious harm or permanent disability for patients is less common, we need strategies in place to detect and correct the key causes of patient harm in healthcare. Our findings are the same across the US and Europe, where 90% of the studies were based. There were fewer studies available from low and middle-Income countries (only 10%), and we need more evidence in those countries,” Dr. Panagioti told MEA Worldwide (MEAWW). 

According to the study, which was published in The BMJ, in terms of actual incidents of patient harm, there were 47,148 cases, of which 25,977 (55%) were preventable.


“The overall patient harm was 12%, while the preventable patient harm was 6%. We, therefore, concluded that 50% of patient harm is preventable. In terms of actual incidents of patient harm, there were 47,148, of which 25,977 could be avoided,” she told MEAWW. 

The World Health Organization (WHO) defines patient harm as “an incident that results in harm to a patient such as impairment of structure or function of the body” which happens “during the provision of healthcare, rather than an underlying disease or injury, and maybe physical, social or psychological.”

The WHO states that patient harm is the 14th leading cause of the global disease burden, comparable to diseases such as malaria and tuberculosis. According to the WHO estimates, there are 421 million hospitalizations globally each year, and about 42.7 million adverse events occur in patients during hospitalizations.


“Patient safety is the absence of preventable harm to a patient during the process of health care and reduction of risk of unnecessary harm associated with health care to an acceptable minimum,” says the WHO.

Some of the causes of preventable harm in healthcare may include unsafe medication practices, medication errors, hospital infections, complications in surgery, and inaccurate and delayed diagnoses, among others. 

The research team, which looked at 70 observational studies, examined the prevalence of preventable patient harm across a range of medical settings, including hospitals and in primary care. They also analyzed the severity and most common types of preventable patient harm.

Describing how preventable harm is determined, Dr. Panagioti says most of the studies use a standard validated six-point scale to assess preventability.

“Expert physicians and/or nurses come together, and they decide whether the recurrence of an incident of patient harm could be avoided by reasonable adaptation to a healthcare process or adherence to guidelines. Based on their judgment, they score the six-point scale. A score of four or higher usually means that the patient harm was preventable,” Dr. Panagioti said. 


The researchers found that incidents relating to drugs and other treatments accounted for the highest or 49% of preventable patient harm. This was followed by incidents related to surgical procedures (23%), healthcare-related infections (16%), and incorrect/missed diagnosis (16%), shows the study. 

Drug management and other therapeutic management incidents accounted for the highest proportion (49%) of preventable patient harm followed by incidents related to surgical procedures (23%), healthcare infections (16%), and diagnosis (16%), says the study. (Getty Images)

Preventable patient harm was more common in patients treated in surgical and intensive care units as compared with patients treated within across general hospitals. The analysis found it to be the lowest in obstetric units.

“An important finding is that preventable patient harm appears to be a serious concern in advanced medical specialties, including intensive care and surgical units. Patients treated in these specialties were more likely to experience preventable patient harm compared with patients treated in general hospitals. The underlying causes of these figures warrant further investigation because current safety standards could be failing to rescue many high-risk patients treated in advanced specialties. Moreover, clinicians in these specialties are often exposed to work pressures and are expected to deliver life-changing decisions quickly which might negatively impact on their personal well-being, a well-known risk factor for preventable medical incidents,” says the paper. 

The study also says the financial cost from "only six selected types of preventable patient harms in English hospitals is equivalent to over 2000 salaried general practitioners or over 3500 hospital nurses each year."

Understanding and mitigating preventable patient harm is a significant public health challenge across the globe, says the team.


“A combination of individual-level improvement strategies (for example, educational interventions for practitioners), system-level improvement strategies (for example, human-centered design of healthcare tasks and work environments), and organizational-level strategies (for example, introducing quality monitoring and improvement processes) are needed for mitigating preventable patient harm. Our findings show that most harm relates to medication, and this is one core area that preventative strategies could focus,” Dr. Panagioti told MEAWW. 

In a linked editorial, experts from the London School of Economics and the Harvard Medical School say the study is a reminder that medical harm is prevalent across health systems, and more importantly, draws attention to how much is potentially preventable.

“Moving forward, efforts need to be focused on improving the ability to measure preventable harm. This includes fostering a culture that allows for more systematic capturing of near misses, identifying harm across multiple care settings and countries, and empowering patients to help ensure a safe and effective health system,” says the editorial.


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 BMJ report Maria Panagioti preventable harm affects one in every 20 patients