Physicians who have the least experience spend significantly more money treating patients than those who have the most experience, and this could have significant implications for recently-qualified doctors, US researchers have warned.

Less-experienced doctors might find themselves excluded from contracting networks or face lower payments, as both private insurers and government programmes look to reward health care providers who delivery quality care at a lower cost, say the authors, from RAND Corporation. 

Reporting their findings in the November edition of the journal Health Affairs, lead author Ateev Mehrotra says that while they are “provocative,” they warrant further examination and need to be affirmed by additional studies.

"It is possible that one driver of health care costs is that newly-trained physicians practice a more costly style of medicine," adds Dr Mehrotra, who is a RAND researcher and associate professor at the University of Pittsburgh School of Medicine.

US commercial health plans and the federal Medicare programme are using cost profiles to identify which physicians account for more health care spending than others, while devising strategies to reward those who provide quality care at a lower cost, the researchers note.

To identify which physician types might be costlier than others, their study used commercial health plan claims for more than one million residents of the US state of Massachusetts from 2004 to 2005 to construct cost profiles for over 12,000 physicians in the state. Costs were evaluated across 600 types of episodes of care that included a patient's illness and the severity of their disease, including whether or not a procedure was performed.

 Physicians who had less than 10 years' experience had 13.2% higher overall costs than those with 40 or more years' experience, the study found. Doctors with 10-19 years of experience were found to have cost profiles that were 10% higher, while those with 20-29 years' experience they were 6.5% higher and for those with 30-39 years' experience the increase was 2.5%.

No association was found between costs and other characteristics such as having had a malpractice claim or disciplinary action, whether or not a physician was boad-certified or the size of the medical practice where they worked. 

A number of factors may explain the findings, the researchers suggest. Recently-trained physicians may be more familiar with and more likely to use new, expensive treatment modalities than older doctors. It is also possible that newer physicians' lack of experience and their uncertainty translates into more-aggressive medical care. And less-experienced doctors may also attract patients with problems that are harder to address, and the current cost profiling methods may not adequately account for these differences, they note.

As newer physicians gain more experience and have longer relationships with their patients, their practice patterns may change and become less costly. However, it is also possible that the cost differences will remain throughout their careers, says the study.

The researchers point out that they did not attempt to judge the quality of care provided, nor did the cost difference noted by the study suggest that less-experienced physicians provide better medical care. And, as the use of cost profiles is relatively new and such tools are still being refined, they say they are cautious about the results.

"Our findings cannot be considered final, but they do underscore the need to better understand physician practice patterns and what influences their behaviour," said Dr Mehrotra.

They highlight the need for postgraduate training programmes and specialty medical boards to educate physicians about their responsibility to be good stewards of health care resources, the authors add.