Medical imaging rates continue to rise despite push to reduce their use

September 03, 2019

Despite a broad campaign among physician groups to reduce the amount of imaging in medicine, the rates of use of CT, MRI and other scans have continued to increase in both the U.S. and Ontario, Canada, according to a new study of more than 135 million imaging exams conducted by researchers at UC Davis, UC San Francisco and Kaiser Permanente. This concerns researchers because medical imaging is widely believed to be overused.

The study, published September 3, 2019 in the Journal of the American Medical Association, is the first of its size to determine imaging rates across different populations. It found that although the growth in imaging slowed in the early 2000s, it ticked back up in recent years for computerized tomography (CT) and magnetic resonance imaging (MRI) in most patient age groups. A notable exception was a decline in CT use in children in recent years.

CT scans use ionizing radiation to create images of the inside of the body, and they deliver a radiation dose far higher than a conventional X-ray, while MRIs use magnetic fields and radio waves to create images and do not expose patients to ionizing radiation. The authors noted that the study does not discuss whether the documented imaging use was appropriate or associated with better patient outcomes.

"Medical imaging is an important part of health care and contributes to accurate disease diagnosis and treatment, but it also can lead to patient harms such as incidental findings, overdiagnosis, anxiety and radiation exposure that is associated with an increased risk of cancer," said lead author Rebecca Smith-Bindman, MD, a UCSF professor of radiology, epidemiology and biostatistics, and obstetrics and reproductive medicine.

Although it is widely believed that imaging rates are declining due to payment and educational efforts that have targeted unnecessary imaging, the authors found a reacceleration in imaging use, with ongoing growth in the use of CT and MRI in adults.

"Like all aspects of medicine, it's important to make sure imaging is justified, and that the potential benefits are balanced against the potential harms," said Smith-Bindman, a member of the Philip R. Lee Institute of Health Policy Studies. "These potential harms of false positive diagnoses and overdiagnoses can impact everyone who undergoes a test and thus need to be considered when imaging is used."

Diana Miglioretti, PhD, biostatistics professor at UC Davis Department of Public Health Sciences and senior author on the study, said there were some hopeful signs among the findings.

"The good news is that rates of CT imaging are starting to come down in children," said Miglioretti, who is also a senior investigator with Kaiser Permanente Washington Health Research Institute. "However, they're still far lower in Ontario than in the U.S., suggesting there is additional room for improvement. It's also important to reduce unnecessary imaging in adults given they are also at risk of radiation-induced cancers."

The researchers analyzed patterns of medical imaging between 2000 and 2016 among a diverse group of 16-21 million adult and pediatric patients enrolled in seven U.S. health care systems and in the universal, publicly funded health care system in Ontario, Canada. For the U.S. data, they included people receiving care in both fully integrated health care systems such as Kaiser Permanente, and systems with mixed insurance including HMOs and PPOs with fee-for-service plans.

"Our capture of medical imaging utilization across seven U.S. health care systems and Ontario, Canada, over a 16-year period provides one of the most comprehensive assessments to date of imaging in children to older adults in North America," said Marilyn Kwan, PhD, co-author and senior research scientist in the Kaiser Permanente Northern California Division of Research.

Among the findings:The authors note that potential overuse of diagnostic testing has been addressed with the "Choosing Wisely" campaign launched in 2012 by the American Board of Internal Medicine Foundation and endorsed by 85 professional medical societies. The effort urges physicians to talk with their patients about whether an imaging study is necessary, free from harm and supported by evidence. Other initiatives, including by the federal Centers for Medicaid and Medicare Services, have created incentives to discourage overuse of imaging by reducing reimbursement rates for certain scans.

The study authors say their findings suggest that neither the financial incentives nor the campaign to reduce use of medical imaging have been entirely effective.

"Although most physicians are aware that imaging tests are frequently overused, there are not enough evidenced-based guidelines that rely on a careful consideration of the evidence, including information on benefits and harms that can inform their testing decisions," Smith-Bindman said. "In the absence of balanced evidence, the default decision is to image."
-end-
Co-authors: Erin J.A. Bowles, LH Kushi, MK Theis, and S. Weinmann of Kaiser Permanente; EC Marlow of UC Davis; SY Cheng of ICES in Toronto, Canada, JR Duncan of Washington University at St. Louis, RT Greenlee of Marshfield Clinic Research Institute, JD Pole of the Pediatric Oncology Group of Ontario, AK Rahm of the Center for Health Research at Geisinger, and NK Stout of the Department of Population Medicine at Harvard Medical School and Harvard Pilgrim Health Care Institute.

Funding: National Cancer Institute grants (R01CA185687 and R50CA2111150) and ICES, funded by an annual grant from the Ontario Ministry of Health, Long-Term Care.

Disclosures: JR Duncan has received personal fees from Bayer. Miglioretti has served as on the advisory board of Hologic.

About UC Davis Health: UC Davis Health is improving lives and transforming health care by providing excellent patient care, conducting groundbreaking research, fostering innovative, interprofessional education, and creating dynamic, productive partnerships with the community. For more information, visit http://www.health.ucdavis.edu .

About UCSF Health: UCSF Health is recognized worldwide for its innovative patient care, reflecting the latest medical knowledge, advanced technologies and pioneering research. It includes the flagship UCSF Medical Center, which is ranked among the top 10 hospitals nationwide, as well as UCSF Benioff Children's Hospitals, with campuses in San Francisco and Oakland, Langley Porter Psychiatric Hospital and Clinics, UCSF Benioff Children's Physicians and the UCSF Faculty Practice. These hospitals serve as the academic medical center of the University of California, San Francisco, which is world-renowned for its graduate-level health sciences education and biomedical research. UCSF Health has affiliations with hospitals and health organizations throughout the Bay Area. Visit http://www.ucsfhealth.org/. Follow UCSF Health on Facebook or on Twitter

University of California - San Francisco

Related Health Care Articles from Brightsurf:

Six ways primary care "medical homes" are lowering health care spending
New analysis of 394 U.S. primary care practices identifies the aspects of care delivery that are associated with lower health care spending and lower utilization of emergency care and hospital admissions.

The mental health impact of pandemics for front line health care staff
New research shows the impact that pandemics have on the mental health of front-line health care staff.

Modifiable health risks linked to more than $730 billion in US health care costs
Modifiable health risks, such as obesity, high blood pressure, and smoking, were linked to over $730 billion in health care spending in the US in 2016, according to a study published in The Lancet Public Health.

Spending on primary care vs. other US health care expenditures
National health care survey data were used to assess the amount of money spent on primary care relative to other areas of health care spending in the US from 2002 to 2016.

MU Health Care neurologist publishes guidance related to COVID-19 and stroke care
A University of Missouri Health Care neurologist has published more than 40 new recommendations for evaluating and treating stroke patients based on international research examining the link between stroke and novel coronavirus (COVID-19).

Large federal program aimed at providing better health care underfunds primary care
Despite a mandate to help patients make better-informed health care decisions, a ten-year research program established under the Affordable Care Act has funded a relatively small number of studies that examine primary care, the setting where the majority of patients in the US receive treatment.

International medical graduates care for Medicare patients with greater health care needs
A study by a Massachusetts General Hospital research team indicates that internal medicine physicians who are graduates of medical schools outside the US care for Medicare patients with more complex medical needs than those cared for by graduates of American medical schools.

The Lancet Global Health: Improved access to care not sufficient to improve health, as epidemic of poor quality care revealed
Of the 8.6 million deaths from conditions treatable by health care, poor-quality care is responsible for an estimated 5 million deaths per year -- more than deaths due to insufficient access to care (3.6 million) .

Under Affordable Care Act, Americans have had more preventive care for heart health
By reducing out-of-pocket costs for preventive treatment, the Affordable Care Act appears to have encouraged more people to have health screenings related to their cardiovascular health.

High-deductible health care plans curb both cost and usage, including preventive care
A team of researchers based at IUPUI has conducted the first systematic review of studies examining the relationship between high-deductible health care plans and the use of health care services.

Read More: Health Care News and Health Care Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.