@article {BouckE322, author = {Zachary Bouck and Graham Mecredy and Noah M. Ivers and Ciara Pendrith and Ben Fine and Danielle Martin and Richard H. Glazier and Joshua Tepper and Wendy Levinson and R. Sacha Bhatia}, title = {Routine use of chest x-ray for low-risk patients undergoing a periodic health examination: a retrospective cohort study}, volume = {6}, number = {3}, pages = {E322--E329}, year = {2018}, doi = {10.9778/cmajo.20170138}, publisher = {Canadian Medical Association Open Access Journal}, abstract = {Background: Many evidence-based recommendations advocate against the use of routine chest x-rays for asymptomatic, low-risk outpatients; however, it is unclear how regularly chest x-rays are ordered in primary care. Our study aims to describe the frequency of, and variation in, routine chest x-ray use in low-risk outpatients among primary care physicians.Methods: In this retrospective cohort study, Ontario residents aged 18 years and older with a periodic health examination (PHE) between Apr. 1, 2010, and Mar. 31, 2015, were identified via administrative claims data. Patients with a recent history (last 3 years) of any of the following were excluded: cardiac or pulmonary disease, high-risk comorbidity (e.g., diabetes), consultations/visits or procedures involving cardiac or pulmonary specialists, cancer and severe chest trauma. The primary outcome, a routine chest x-ray, was defined as at least 1 chest x-ray claim within 7 days after a PHE.Results: While a routine chest x-ray followed only 2.42\% of 2 847 508 PHEs, one-quarter of family physicians (499/2031) ordered chest x-rays for more than 5.0\% of their PHEs (interquartile range 1.5\%{\textendash}5.0\%) and accounted for 62.9\% of all tests observed. Routine chest x-ray use declined by 2.0\% per quarter (adjusted rate ratio 0.98, 95\% confidence interval [CI] 0.97{\textendash}0.98). Older age (45{\textendash}64 yr v. 18{\textendash}44 yr, adjusted odds ratio [OR] 1.82, 95\% CI 1.78{\textendash}1.86; >= 65 yr v. 18{\textendash}44 yr, adjusted OR 2.48, 95\% CI 2.39{\textendash}2.58) and male sex of the patient (OR 2.19, 95\% CI 2.14{\textendash}2.24) and male sex of the provider (OR 1.55, 95\% CI 1.51{\textendash}1.59) were significantly associated with increased odds of a routine chest x-ray being ordered.Interpretation: It is relatively uncommon for a chest x-ray to be ordered as part of a PHE in Ontario; however, the substantial variation observed among physicians suggests potential for interventions targeted at the most frequent users.}, URL = {https://www.cmajopen.ca/content/6/3/E322}, eprint = {https://www.cmajopen.ca/content/6/3/E322.full.pdf}, journal = {Canadian Medical Association Open Access Journal} }