PCPs miss the boat, order lung screening exams for asymptomatic patients
The National Lung Screening Trial (NLST) observed a 20 percent reduction in lung cancer mortality among current and former heavy smokers undergoing low-dose spiral CT, though to date, no major expert group, including the U.S. Preventive Services Task Force, has recommended screening for asymptomatic individuals, according to the study’s authors.
To determine whether physicians were adhering to recommendations, Carrie N. Klabunde, PhD, of the division of cancer control and population sciences at the National Cancer Institute in Bethesda, Md., and colleagues conducted a nationally representative survey of U.S. primary care physicians to examine their lung cancer screening practices.
Of the 962 primary care physicians who responded, 57 percent had ordered at least one of three lung cancer screening tests (chest radiograph, low-dose spiral CT or sputum cytology) in the past 12 months for asymptomatic patients. Thirty-eight percent ordered no tests.
Further analysis showed that physicians were more likely to order screening tests if they believed they were recommended by expert groups, if they graduated from medical school more than 20 years ago and if their patients had asked about screening.
“Our results showing gaps in primary care physicians’ knowledge of lung cancer screening and use of unproven screening modalities suggest that in the U.S.—where most cancer screening occurs opportunistically rather than through organized programs—a substantial proportion of the adult population could be inappropriately screened unless there are concerted efforts to inform primary care physicians of appropriate interpretation of NLST findings and how best to apply them in practice,” wrote the authors.
Klabunde et al said that NLST results may have been used to promote the effectiveness of lung cancer screening, but it’s important to keep those findings in context. The results are specific to individuals aged 50 to 75 who were current or former smokers, so any recommendations based on the NLST should apply only to that high-risk population and only to low-dose CT screens.
“Primary care physicians’ ordering of unproven lung cancer screening technologies has several implications,” wrote the authors. “There is potential for psychological harm from false-positive or false-negative test results, and physical harm from invasive procedures performed to follow up false-positive screening tests.” The authors also stressed that unproven screening techniques could continue to drive up healthcare costs.
In an email to Health Imaging, Klabunde said she believed that radiology computerized decision support could play a role in curbing inappropriate test ordering by informing physicians of appropriate indications for ordering.
“In addition, some clinical decision support systems provide a link to the most up-to-date, authoritative clinical practice guidelines, which can be very helpful to busy primary care physicians who can’t be expected to stay on top of the latest guidelines in the many different clinical areas that they cover in the typical primary care practice setting,” she said.