To the Editor The study by Dr Gialdini and colleagues1 evaluated the long-term risk of ischemic stroke in patients with perioperative atrial fibrillation (AF). There is a methodological issue that arises with the use of administrative data to draw clinical inferences.
According to the sensitivity (88%) and specificity (86%) of the diagnosis codes given in the text, as well as the prevalence of AF of 1.43%, the positive predictive value of a diagnosis of perioperative AF in this study would only be 8.4%. In other words, a patient would be much more likely not to have the syndrome than to have it.
Kurlansky P. Stroke Risk Following Perioperative Atrial Fibrillation. JAMA. 2014;312(22):2410. doi:10.1001/jama.2014.14490