VARIABLES ASSOCIATED WITH HOSPITAL ARRIVAL TIME AFTER STROKE - EFFECTOF DELAY ON THE CLINICAL-EFFICIENCY OF EARLY TREATMENT

Background and Purpose A limiting criterion for the eligibility of pat ients in clinical trials investigating acute stroke therapies is that time between onset of symptoms and arrival in the hospital should fall within the ''therapeutic window.'' The aims of this study were to est imate hospital arrival time in an unselected sample of stroke patients , to assess the association with some clinical and demographic variabl es, and to evaluate the effects of the delay on the clinical efficienc y of an effective treatment. Methods We evaluated the delay in hospita l arrival time in 189 patients (84 men, 105 women; mean age, 76.5 year s) prospectively collected in the S Orsola-Malpighi Community Teaching Hospital in Bologna, Italy. Cutoffs of 2 and 5 hours were chosen to a llow for hypothetical treatment within 3 and 6 hours, respectively. Ex act multiple logistic regression was used to predict the delay as a fu nction of dichotomized age, sex, symptoms on awakening, day of the wee k, hour of the day, area of residence, level of consciousness, and lev el of motor power defect. We then projected the effectiveness of tissu e plasminogen activator (TPA) on disability as estimated with the aid of the odds ratio from the National Institute of Neurological Disorder s and Stroke (NINDS) rt-PA Stroke Trial onto our unselected sample to evaluate clinical efficiency of treatment as a function of arrival tim e and of hypothetical effects of educational efforts to reduce it. Res ults The mean interval between onset of-symptoms and hospital arrival was 680 minutes; 59 patients (31%) arrived within 2 hours and 100 (53% ) within 5 hours. Onset of symptoms when awake, drowsiness or coma, an d paralysis of at least one limb were the only independent predictors of hospital arrival within 2 and 5 hours in both the total sample and the subgroup of patients who were awake at stroke onset. The effective ness of 17%, extrapolated with the aid of the odds ratio of 1.6 of hav ing a favorable outcome (Barthel Index greater than or equal to 95 at 3 months) in treated versus untreated patients in the NINDS rt-PA Stro ke Trial, corresponded to a projected clinical efficiency of 5%. This could be doubled by hypothesizing a 100% effect of educational efforts in reducing the delay in hospital arrival time. Conclusions Patients with milder symptoms, for whom treatment might be more effective, were less likely to arrive in time for therapy. The proposed model of the relationship between the delay in hospital presentation after a stroke and the clinical efficiency of a given treatment might be useful for planning future clinical trials on early stroke treatment and predicti ng the impact of an educational program aimed at shortening arrival ti me.