[International Stroke Trial Switzerland: some epidemiologic data].

Randomised trials provide the best evidence on the effects of treatment on a particular disease. They can also provide valuable data on outcome. In the present article, data from 1631 Swiss patients randomised in the International Stroke Trial (IST) are presented. Baseline characteristics and outcome in the Swiss patients were compared with the 17,804 patients randomised in other countries. On average, compared with other countries, Swiss patients were: 2.5 years older (CI: 1.9-3.1; p < 0.001); more likely to have presented with total anterior circulation infarcts (28 vs 23%); less likely to have lacunar strokes (16 vs 25%; p < 0.00001); more likely to be randomised and treated early (within 3 hours, 7 vs 4%, and within 6 hours, 25 vs 15%; p < 0.00001). However, Swiss patients were more likely to be dead or dependent 6 months after the stroke (66.9 vs 62.2%; p < 0.00001). The difference in death or dependency was almost entirely explained by the difference in age and baseline severity of strokes. These data highlight the difficulties inherent in between-country comparisons of outcome after stroke. They also emphasise the need for international multicentre trials to use methods of randomisation (either stratification or minimisation), as IST did, to ensure balance of prognostic factors within each participating country; to do otherwise might confound the assessment of the effect of treatment.

RCT Entities:   Population Interventions Outcomes