Urolithiasis and Frequent CT Scans: Does Chronic Pain Play a Role?

Introduction: Urolithiasis is among the top 10 causes of Emergency Department (ED) visits in the United States. Approximately 50% of these patients undergo abdominopelvic CT scan, many more than once. We hypothesized that chronic pain conditions may contribute to frequent CT scans in patients who are evaluated in ED for urolithiasis. Methods: A retrospective review of patients presenting to our tertiary care and the associated satellite EDs for urolithiasis, during the period 12/2012-05/2013, was performed. Patients with multiple ED visits and two or more abdominopelvic CT scans in any 6-month period were labeled as the frequent CT group. Control group consisted of similar patients who had no more than one CT scan in any 6-month period. Background information, number of CT scans for urolithiasis and other reasons, and the presence of chronic pain (established pain clinic visits, chronic pain medication, known chronic pain syndromes) were captured from charts. Wilcoxon rank-sum test and Fisher's exact test were used to compare variables. Multivariable logistic regression was performed to identify predictors associated with frequent CT scans. Results: We identified 185 patients with frequent CTs and 139 patients in the control arm. Frequent CT scans were independently associated with chronic pain (odds ratio [OR]: 2.67, confidence interval [95% CI]: 1.55, 4.50), age (OR: 0.73, 95% CI: 0.60, 0.89), history of prior urolithiasis (OR: 2.15, 95% CI: 1.11, 4.15), and Medicaid insurance status (OR: 3.94, 95% CI: 1.66, 9.35). Conclusion: Chronic pain is a significant contributing factor to frequent CT scans among patients presenting to ED with urolithiasis, leading to increased radiation exposure and healthcare costs.