SonoStudy: CT vs Ultrasound, Community vs Academic Ctr – kids evaluated for appendicitis

In a recent Mescape news article, a topic near and dear to my heart (and, yes, I know I have a lot of them – but decreasing radiation exposure, length of stay, and health care cost are a few), there was a study highlighted that compared community practice versus academic practice in the evaluation of children with abdominal pain that required imaging for ruling out appendicitis. It basically states that community practice do more CT scans and the results are less sensitive. Ive copied the article below, but it got me thinking…. there are quite a few factors that are different in community practice from academic practice and I wonder if they bias these results. Some community practice groups do perform published research studies, but academic centers are well known for being the research hub – does that mean they are more in tune with the talk around town? or that they are more progressive? Well, that can be argued as quite a few academic centers may seem like they are resistant to change. Also, is ultrasound available 24/7? Many community practice centers do not have access to ultrasound outside of business hours, and I know that a few academic centers are also ultrasound-openic overnight. The radiologists who read these studies may not even be in the same country as out-sourcing has become more common than ever before. Would that decrease the sensitivity? It’s hard to say, but I doubt they would be in demand if they made that many mistakes. Surgeons are more reluctant to take a patient to the operating room without a CT-proven appendicitis and emergency physicians are less likely to discharge a patient without a clear diagnosis for right lower quadrant pain. Do any of these factors play into this? Hmmmm…..well, in a prior post about a study done on ultrasound versus CT, the numbers suggest that change is needed…. somewhere along the line of the work up.

“Community hospitals are more than 4 times more likely than pediatric institutions to use radiation-exposing computed tomography (CT) scans and 80% less likely to use ultrasound for pre-appendectomy evaluations in children, study results suggest. Jacqueline M. Saito, MD, MSCI, and colleagues from Washington University School of Medicine in St. Louis, Missouri, also found that both diagnostic tools were less sensitive for appendicitis in the community hospital setting. As previously reported by Medscape Medical News, CT screening of children with abdominal pain has skyrocketed while appendicitis rates remain unchanged, adding to growing concerns regarding the link between excessive radiation exposure and cancer risk later in life. “Broadly-applicable strategies to systematically maximize diagnostic accuracy for childhood appendicitis, while minimizing ionizing radiation exposure, are urgently needed,” the authors write, noting that evaluations may be streamlined by using algorithms developed with broad validity to decrease reliance on preoperative imaging and radiation exposure while avoiding unnecessary hospital transfers, admissions, operations, and missed diagnoses. The retrospective study was published online December 24 in Pediatrics.

For the study, researchers reviewed the records of 423 children who had undergone surgery for presumed appendicitis. Preoperative imaging was performed in 93.4% of cases; final diagnoses included acute appendicitis (69.0%), perforated appendicitis (23.6%), and normal appendix (7.3%). After adjusting for age, sex, race/ethnicity, body mass index, symptom duration, and white blood cell count, researchers found that children initially evaluated at a community hospital were 4.4 times more likely to have undergone a preoperative CT scan (odds ratio [OR], 4.37; 95% confidence interval [CI], 1.70 – 11.19; P = .002) and 80% less likely to have had an ultrasound performed (OR, 0.20; 95% CI, 0.07 – 0.58; P = .003) than those at a pediatric facility. About 15.1% of children underwent both ultrasound and CT before surgery, particularly if they were girls (OR, 4.51; 95% CI, 1.47 – 13.82; P = .008) or had a lower body mass index percentile (OR, 0.98; 95% CI, 0.96 – 1.00; P = .03), longer symptom duration (OR, 1.81; 95% CI, 1.15 – 2.86; P = .01), or lower white blood cell count (OR, 0.87; 95% CI, 0.78 – 0.97; P = .01). Most children undergoing both tests had the ultrasound first (46/64, 71.9%), and normal/indeterminate results were followed up with CT (OR, 17; 95% CI, 7.7 – 37.0). Although high overall, CT scans performed at pediatric hospitals tended to be more sensitive for any appendicitis and for perforated appendicitis than those done at community hospitals (98.8% vs 93.4% [P = .07] and 75.0% vs 49.0% [ P = .045], respectively). Sensitivities were highest for older children (aged 13 – 18 years) and those not obese; insufficient numbers of underweight children were available for analysis. Accuracy of ultrasound for diagnosing appendicitis was found to be moderate in the pediatric hospital setting (weighted κ, 0.36; 95% CI, 0.24 – 0.48) and highest among older children (aged 13 – 18 years; weighted κ, 0.38; 95% CI, 0.22 – 0.54) and boys (weighted κ, 0.40; 95% CI, 0.21 – 0.55); rarity of use in community hospitals precluded any evaluation of ultrasound sensitivity in this setting. “Variation in diagnostic imaging use for pediatric appendicitis by initial evaluation location might stem from multiple factors, such as availability of imaging or the perceived need for diagnosis confirmation,” the authors comment, noting that ultrasound may be less available in community hospitals and that emergency physicians may have low risk tolerance for pediatric diagnostic errors and malpractice claims, preferring to place their confidence in CT scans.” Pediatrics. Published online December 24, 2012. Abstract

This has been talked about in further studies, as the ED length of stay can be reduced when utilizing US, instead of CT


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