Patients harmed by prescriptions
Almost 11 per cent of patients in New Zealand general practices were harmed by medicines prescribed to them, a new study has found.
‘‘Medication-related harm in general practice is common,’’ concluded the researchers, led by Dr Sharon Leitch of the University of Otago’s Medical School.
While 78.9 per cent of the harms were classed as minor, 21 per cent were moderate or severe. Eighteen patients were hospitalised as a result of prescriptions and three people died, the study found.
Severe harms included renal failure, pulmonary embolism, myocardial infarction, and morphine overdose.
Moderate harm included fractures, untreated anaemia and poor diabetic control. Minor harms were short-lived and relatively trivial and included rashes, vomiting and inconvenience.
The numbers are probably conservative because not all harms were recorded in the medical records.
But 81.2 per cent of medication-related harms were considered not preventable, for example weight gain caused by oral contraceptives. Almost 19 per cent were classed preventable, such as cardiac arrest.
Doctors want to help people and to end up harming them, even in minor ways, ‘‘leaves room for improvement’’, Leitch said in an interview.
The study reinforces the ‘‘need for vigilance and care in routine medication use’’, the authors concluded.
It’s difficult to compare New Zealand’s medicinal harm rate with overseas experiences because of different terminology, different record keeping and different study designs, Leitch said. But she thought our levels were ‘‘not out of step with’’ with other countries.
Other researchers have estimated medication harms, but these methods ‘‘provide a limited perspective’’, the authors wrote.
Clinical trials are usually short and compensation claims to the likes of ACC incomplete.
The starting point for this research was that ‘‘the extent of medication-related harm in general practice is unknown’’.
The researchers wanted insights into ‘‘real world’’ practices and harms.
They accessed the medical records from 44 randomly selected general practices for the three years 2011-13 and reviewed 9076 randomly selected patient records. Some 7308 patients received 175,657 prescriptions for 846 different medications from their general practices.
Reviewers identified 1762 medication-related harms in 10.8 per cent of patient records
After controlling for various factors, the researchers found that increasing age and more frequent medical appointments led to higher risk of medication caused harms.
Compared to patients aged 15-59 years, those aged 60-74 years had double the odds of experiencing medication-related harm, and patients 75 years and older had triple the odds.
Gender was not a factor. There was no evidence that social deprivation increased risk. Pasifika ethnicity lowered risk.
Those patients who attended a small general practice were also better off than those who attended larger practices. The location of practices was not important.
Although the study period started about a decade ago, the research was applicable to today’s world because there have been few appreciable changes to New Zealand general practice. If anything, prescription rates and the prescribing of multiple medicines has increased.
The drugs most likely to cause problems were cardiovascular medications, antineoplastic agents (used to treat cancer) and immunomodulatory agents (which affect the immune system in various ways).
‘‘Reducing medication-related harm is a top priority for improving patient safety,’’ the authors stated.