Similarity of patient characteristics and outcomes in consecutive data collection on stroke admissions over one month compared to longer periods

BACKGROUND: The usefulness of time-limited consecutive data collection compared to continuous consecutive data collection in conditions which show seasonal variations is unclear. The objective of this study is to assess whether one month of admission data can be representative of data collected over two years in the same hospitals. METHODS: We compared the baseline characteristics and discharge outcomes of stroke patients admitted in the first month (October 2009) of the Anglia Stroke Clinical Network Evaluation Study (ASCNES) with the routinely collected data over 2 years between September 2008 and April 2011 from the same 8 hospital trusts in the Anglia Stroke & Heart Clinical Network (AS&HCN) as well as seasonal cohorts from the same period. RESULTS: We included a total of 8715 stroke patients (October 2009 cohort of ASCNES (n = 308), full AS&HCN cohort (n = 8407 excluding October 2009)) as well as cohorts from different seasons. All cohorts had a similar median age. No significant differences were observed for pre-stroke residence, pre-stroke modified Rankin, weekend vs. weekday admission, time of admission, patients with atrial fibrillation, type of stroke, admission systolic blood pressure, use of thrombolysis (rTPA), in-patient mortality and discharge destination. There were statistically significant differences between cohorts with regard to Oxfordshire Community Stroke Project Classification. CONCLUSIONS: Stroke patients admitted in one month had largely indistinguishable characteristics and discharge outcomes to those admitted to the same trusts in three separate seasons and also over two years in this cohort