Journal Club Summary
Methodology Score: 4/5
Usefulness Score: 4/5
Smith-Bindman R, et al.
N Engl J Med. 2014 Sep 18;371(12):1100-10.
This multicentre randomized trial of over 2700 patients with suspected nephrolithiasis compared an ultrasound first approach, either point-of-care (POCUS) or official radiology ultrasound, with a CT first approach for the diagnostic workup of flank pain. Although many patients in the ultrasound first group subsequently underwent CT scans, they were still exposed to significantly less ionizing radiation over a 6 month period. JC attendees also remarked that in in carefully selected patients with suspected nephrolithiasis, the rate of significant adverse events was extremely low in all groups – well under 1%.
By: Dr. Sebastian Dewhirst
Epi Lesson: Selection Bias in RCTs
Even though a clinical trial is randomized, this does not mean it cannot be subject to selection bias. Always look at the study flow figure (generally figure 1) to determine how many eligible patients were not included then assess whether the authors reasonably explain why these eligible but excluded patients were not systematically different from those who were randomized.
By: Dr. Lisa Calder