This Mount Sinai news release describes a small study aimed at testing whether chest ultrasounds are as effective at diagnosing pneumonia in children as chest X-rays, the current diagnostic method of choice. Patients were randomized into either a test group, which received a chest ultrasound and a possible follow-up chest X-ray, versus a control group which received first a chest X-ray and then a chest ultrasound. The release does a good job of explaining the study results, and the potential cost savings here and in lesser-developed countries. Weaknesses are no mention of an investigator’s consulting relationship to an ultrasound company and lack of discussion of study limitations.
Pneumonia is the number one killer of children on the planet, according to the World Health Organization (WHO). While chest X-rays are the accepted means of diagnosing pneumonia, WHO points out that in three-quarters of the world, the necessary equipment isn’t available, meaning an alternative that is both more widely available and cheaper than radiography would be a great boon for health care. While this was a small study, it provides evidence that ultrasound technology, being both cheaper and more portable, could help fill the gaps in health care in both richer and poorer regions.
This release earns praise for clearly mentioning the cost savings derived from the use of chest ultrasounds versus chest X-rays in treating patients in the study — $9,700 from 191 patients. The release could have been even even more helpful by adding information showing chest ultrasounds cost about two-and-a-half times less than chest X-rays ($140 versus $370 respectively). The release also might have mentioned that there’s a large initial outlay for ultrasound machines that may make them too expensive in the developing world. Another upfront cost not mentioned is the expense of training emergency medicine physicians (and presumably also internal medicine, pediatric and family medicine physicians) to do this procedure.
The release clearly stated that chest ultrasounds effectively diagnosed study patients who had pneumonia as well as chest X-rays. There were 38.8 percent fewer chest X-rays required for a pneumonia diagnosis in the investigational arm of the study compared to the control group of the study. The study also showed that stays in the emergency department by ultrasound-only patients were almost a half-hour shorter than those of the control group.
We offer a word of caution, however. The release didn’t explain how the pneumonia cases were actually diagnosed so we cannot determine if the ultrasound really was accurate and effectively diagnosed study patients who had pneumonia.
The release points out that there was no increase in adverse events reported during the study, nor were there any cases where pneumonia was not appropriately diagnosed. There is the potential for some harms that aren’t addressed, namely missed diagnosis and the identification of small pneumonias that don’t need to be treated (overdiagnosis).
“In the era of precision medicine, lung ultrasound may also be an ideal imaging option in children who are at higher risk for radiation-induced cancers or have received multiple radiographic or CT imaging studies,” according to the lead study author. This benefit in terms of harms reduction might have been stressed even more. Ultrasound screening could be safer in the long run for children than X-ray since repeated exposure to radiation presents a cumulative risk for cancer. Radiation oncology experts and the FDA have long called for reduced reliance on routine X-ray and computerized tomography (CT) screening in children unless the benefits outweigh the risks. More than 100 professional organizations including pediatricians, radiation physicists and oncologists have signed on to the “Image Gently” campaign which urges the use of ultrasound instead of radiation when feasible.
The release makes clear that this was a randomized, controlled trial comparing chest ultrasound versus chest X-rays as a diagnostic tool for identifying pneumonia in young patients. Participants either received an ultrasound possibly followed by a chest X-ray, if needed, in the investigational arm, or a chest X-ray followed by a chest ultrasound in the control group. However, as noted above, it isn’t explained how the pneumonia cases were actually diagnosed. This reduces the quality of the study. Ultrasound should correctly diagnose the larger pneumonias without problems, but small ones can be missed or they may be overdiagnosed. The published article briefly discusses the lack of accuracy in its discussion section. It appears to rely heavily on a meta-analysis of previous studies involving ultrasound accuracy.
The study states: “Second, we were unable to calculate test performance characteristics adhering to the STARD (Standards for the Reporting of Diagnostic accuracy studies) statement due to the fact that 38.8% of the subjects in the investigational arm did not receive a CXR [chest x-ray] that would have served as a practical reference standard. By design, our sonologists were not blinded to CXR results in the control arm so that the information could be used to guide treatment. Lack of blinding to a reference standard could be a potential source of bias in
calculated test performance characteristics for LUS.”
This release doesn’t engage in disease-mongering.
The release notes that the study was conducted at the Icahn School of Medicine at Mount Sinai but doesn’t disclose sponsors or potential conflicts of interest. According to the journal article, one of the researchers has a consulting relationship with an ultrasound company. This should have been included in the release.
The release adequately explains that chest X-rays are the diagnostic method of choice for determining cases of pneumonia, according to the World Health Organization. The study’s primary goal was to determine if chest ultrasounds were an adequate alternative to chest X-rays. A non-imaging method used to diagnose pneumonia is a physical examination.
The release does make a point that ultrasound technology is widely available in health care facilities around the world. We would have liked for the release to include the fact that in perhaps three-quarters of the world, there is a lack of facilities that can provide even diagnostic X-rays. This fact, attributed to the WHO in the journal article, is absent in the news release. High resolution ultrasound machines would be even further out of reach in these countries.
The novelty of a safe and cheaper alternative to expensive radiography that could provide equivalent diagnostic precision is clearly enough to warrant this release.
We don’t believe the news release relies on unjustifiable language to summarize the potential benefit of substituting ultrasound over X-Ray in screening for pediatric pneumonia.