A higher use of resources by US physicians is associated with a reduced risk of malpractice claims, finds a study published by The BMJ this week.
However, the researchers say it is uncertain whether higher spending is defensively motivated.
Defensive medicine is defined as medical care provided to patients solely to reduce the threat of malpractice liability rather than to further diagnosis or treatment.
In the United States most physicians report practicing defensive medicine to reduce malpractice liability. However, there are no studies of whether greater resource use by physicians - defensively motivated or not - is associated with reduced risk of malpractice claims.
So a team of US-based researchers set out to investigate whether physicians who provide more costly care in a given year are less likely to face malpractice claims the following year.
They linked data on nearly 19 million hospital admissions in Florida between 2000 and 2009 to the malpractice history of over 24,000 physicians in seven specialties.
They also tested whether obstetricians with a greater tendency to perform caesarean deliveries in a given year (commonly considered a defensive practice) had lower malpractice claims the following year.
Differences in patient characteristics and diagnoses were taken into account.
Overall, 4,342 malpractice claims were filed against physicians (2.8% per physician year). Malpractice rates varied across specialty, ranging from 1.6% per physician year in pediatrics to 4.1% per physician year in general surgery and obstetrics and gynecology.
Across all specialties, greater average spending by physicians was associated with reduced risk of incurring a malpractice claim.
For example, in internal medicine, the probability of experiencing an alleged malpractice incident in the following year ranged from 1.5% in the bottom spending fifth ($19,725 per hospital admission) to 0.3% in the top fifth ($39,379 per hospital admission).
Similar associations were seen among pediatricians, surgeons, and obstetricians. Family medicine physicians were the only physicians where this association was not observed.
Furthermore, these relations held after adjusting for patient characteristics and accounting for physician characteristics such as patient mix, clinical skills, or communication skills.
The authors say that this is an observational study so no definitive conclusions can be drawn about cause and effect. They also highlight weaknesses, including the lack of information on illness severity and uncertainty around whether higher spending is defensively motivated.
Nevertheless, they say their findings suggest that greater resource use, whether it reflects defensive medicine or not, is associated with fewer malpractice claims.
This is an important question that explores the contentious issues of defensive medicine and malpractice risk in the U.S. healthcare system, write Tara Bishop and Michael Pesko at Weill Cornell Medicine, New York in an accompanying editorial.
They argue that it's too early to say whether defensive medicine protects doctors against malpractice claims, but say these results "highlight the need for future research in this area."
It may be tempting for physicians to use the results to justify ordering unnecessary tests and procedures in order to reduce their malpractice risk, they explain. Instead, "we should consider Jena and colleagues' study as a contribution to our understanding of malpractice risk."
"The study shows that we need to better understand defensive medicine and how this type of practice impacts both patients and physicians," they conclude.