Time to computerized tomography scan, age, and mortality in acute stroke

Background: Time to computerized tomography (CT) is important to institute appropriate and timely hyper-acute management in stroke. We aimed to evaluate mortality outcomes in relation to age and time to CT scan. Methods: We used routinely collected data in eight National Health Service Trusts in East of England between September 2008 and April 2011. Stroke cases were prospectively identified and confirmed. Odds ratios for unadjusted and adjusted models for age categories(24 hours) and the in-hospital and early(<7 days) mortality outcomes were calculated. Results: Of 7,693 patients (mean age 76.1 years, 50% male) included, 1,151(16%) died as inpatient and 336(4%) died within seven days. Older patients and those admitted from care home had a significantly longer time from admission until CT (p<0.001). Patients who had earlier CT scans were admitted to stroke units more frequently (p<0.001) but had higher in-patient(p<0.001) and seven-day mortality(p<0.001). Whilst older age was associated with increased odds of mortality outcomes, longer time to CT was associated with significantly reduced within 7 day mortality(corresponding ORs for above time periods were 1.00, 0.61(0.39-0.95), 0.39(0.24-0.64) and 0.16(0.08-0.33) and in-hospital mortality(ORs 1.00, 0.86(0.64-1.15), 0.57(0.42-0.78) and 0.71(0.52-0.98)). Conclusions: Older age was associated with a significantly longer time to CT. However, using CT scan time as a benchmarking tool in stroke may have inherent limitations and it does not appear to be a suitable quality marker