The research, published in the British Medical Journal, reviewed evidence from 70 different studies reporting preventable harm in a range of medical settings including hospitals and primary care.
“We need a culture that strongly encourages the diligent reporting of near misses”
The analysis found 6% of patients had been affected by preventable harm, causing permanent disability or death in 12% of cases.
Most incidents of preventable harm related to drugs, other therapeutic management of patients and invasive medical or surgical procedures and were more common in surgical and intensive care units, the study found.
The researchers not only highlighted the human cost but concluded avoidable harm was a major financial burden to health systems across the globe.
For example, in England they worked out the cost from just six types of preventable harm in hospital care was equivalent to paying 2,000 GPs or more than 3,500 nurses each year.
Previous studies have looked at overall patient harm across different settings but this was said to be the first to focus on preventable harm.
A team of researchers led by the National Institute for Health Research Greater Manchester Patient Safety Translational Research Centre reviewed 70 observational studies involving more than 337,000 mostly adult patients.
Of those patients 28,150 experienced harmful incidents and 15,419 experienced harm that could have been avoided, the analysis found.
Incidents relating to drugs and other treatments accounted for nearly half – 49% – of all preventable harm.
Compared with general hospitals, preventable harm was found to be more common in patients treated in surgical and intensive care units and was lowest in obstetric units, according to the study.
The researchers said their findings showed preventable harm was “a serious problem across medical care settings”.
They highlighted the need to take action to address major sources of harm – such as drug errors – with a greater focus on advanced medical specialities.
“It is equally imperative to build evidence across specialties such as primary care and psychiatry, vulnerable patient groups, and developing countries,” the paper added.
Meanwhile, more consistent research data was needed to inform efforts to reduce avoidable harm.
In a linked editorial, experts at the London School of Economics and Harvard Medical School said the research drew attention to the extent of preventable harm.
They agreed there was a need to improve the gathering of information and data on incidents where patients were harmed as well as “near misses”.
“We need a culture that strongly encourages the diligent reporting of near misses, all of which are learning opportunities for staff and systems,” they stated.
They said it was also “essential” to get patients’ perspectives and that patients and their families should be involved in exploring how and why mistakes were made.
“Patients and their families can capture important information from their experience of care, which can be crucial to understanding factors that led to harm, such as lapses in communication, staffing issues, and the care environment,” they wrote.