Sex-related Differences in Emergency Department Renal Colic Management: Females Have Fewer Computed Tomography Scans but Similar Outcomes.

Abstract

Sex-related differences occur in many areas of medicine. Emergency department (ED) studies have suggested differences in access to care, diagnostic imaging use, pain management, and intervention. We investigated sex-based differences in the care and outcomes for ED patients with acute renal colic. This was a multicenter population-based retrospective observational cohort study using administrative data and supplemented by structured chart review. All patients seen in Calgary Health Region EDs between January 1 and December 31, 2014, with an ED diagnosis of renal colic based on the following ICD-10 codes were eligible for inclusion: calculus of kidney (N200), calculus of ureter (N201), calculus of kidney with calculus of ureter (N202), hydronephrosis with renal and ureteral calculous obstruction (N132), unspecified renal colic (N23), and unspecified urinary calculus (N209). ED visit data and test results were accessed in the regional ED clinical database. Stone characteristics were captured from diagnostic imaging reports. Regional hospital databases were used to identify subsequent ED encounters, hospital admissions, and surgical procedures within 60days. Outcomes were stratified by sex. The primary outcome, intended as a marker of overall effectiveness of ED care, was the unscheduled 7-day ED revisit rate among patients who were discharged home after their index ED visit. Secondary outcomes included ED pain management as reflected by administration of narcotics or intravenous nonsteroidals, the performance of advanced imaging-either ultrasound (US) or computed tomography (CT), and the proportion of patients who required hospitalization or surgical intervention within 60days. From January 1 to December 31, 2014, a total of 3,104 eligible patients were studied: 1,111 women (35.8%) and 1,993 men (64.2%). Baseline characteristics, access times, analgesic use, and admission rates were similar in both groups. Men were more likely to have CT (68.9% vs. 58.5%, difference=10.4%, 95% confidence interval [CI]=6.8 to 14.0) while women were more likely to have US (20.8% vs. 9.6%, difference=11.2%, 95% CI=8.4 to 13.9). At 7days, 17.9% of women and 19.0% of men who were discharged after their index ED visit required an ED revisit (difference=1.1%, 95% CI=-2.8 to 4.9). Men were more likely to be hospitalized at 7days (9.8% vs. 6.5%, difference=3.3%, 95% CI=0.6 to 6.0). This study shows greater reliance on US in females but no other sex-specific differences in the management of ED patients with acute renal colic. Higher CT use in men was not associated with improved outcomes, and we found no important differences in access to care, diagnostic or treatment intensity, or revisit rates as a marker of care effectiveness.