Practice variation: Why it matters and where it's headed

Medical professionals from senior clinicians to nurse practitioners believe that practice variation needs to be reduced in the clinical setting, but they aren’t optimistic about change any time soon, research published in PLOS ONE this month suggests.

Lead author David A. Cook, MD, MHPE, and colleagues at Mayo Clinic surveyed 178 board-certified physicians, 60 nurse practitioners and 12 physician assistants in an attempt to gauge the field’s perception about practice variation—the idea that while standards and guidelines exist, clinicians often differ in their medical practices.

“When standards of care in medicine are clear, practice patterns are similar in every part of the country,” Mark A. Hlatky, MD, and Anthony N. DeMaria, MD, wrote in a JACC editorial in 2013. “When there is no clear evidence on the best practices, however, different physicians will adopt different approaches on the basis on their beliefs, training, incentives and the local ‘practice style.’”

For nearly two decades, color-coded maps of the U.S. have uncovered vast differences in the use of nearly every medical test and procedure across the country, Hlatky and DeMaria said. Rates of invasive cardiac procedures alone vary six-fold across different healthcare regions.

“But if we celebrate diversity in most areas of American life, why does it matter if medical practice varies, too?” the authors wrote.

Some practice variation is justified, Cook et al. said, but clinicians agree that roughly one third is unwarranted, which can lead to underuse of effective care, overuse of ineffective care and emphasis on physician opinions rather than patient preferences. Practice variation has also been shown to push healthcare costs up while producing mediocre patient outcomes.

“Given these suboptimal results, we believe that before further trying to solve the problem of practice variation, we ought to better understand the nature of practice variation itself, including clinician beliefs about the issue,” Cook and co-authors wrote.

The team surveyed both experienced clinicians and younger physicians through an internet-based questionnaire between February and April 2016. The participants, who specialized in either family medicine, general internal medicine or cardiology, were asked about their beliefs in regard to practice variation, their thoughts about the credibility and utility of clinical guidelines and how those beliefs vary by provider, time in practice, specialty and practice location.

On a scale from 1 to 6, ranging from strongly disagreeing to strongly agreeing, the clinicians seemed to agree that practice variation should be reduced—a 4.5 out of 6—but agreed less strongly that such a shift is realistic. There was a general consensus that variation can be justified based on situational differences, but 94 percent of respondents said they adhered to and depended on current practice guidelines.

Participants also strongly agreed that clinicians should help reduce healthcare costs, but rated the likelihood of practice variation reduction changing that at just a 4.4.

More experienced clinicians were less likely to favorably rate factors that could help standardize practice, Cook and colleagues reported, while nurse practitioners, physician assistants and less experienced clinicians were more idealistic. All respondents rated differences in clinician style and experience as the most important variables that influence practice variation.

“Physicians seem to have lingering doubts that practice variation will be reduced,” the authors wrote. “It will be difficult to fix the problem if those involved fail to recognize its magnitude, importance or potential for correction. Changing attitudes will require that beliefs be acknowledged, needs understood, evidence sought and misperceptions corrected.”