L J Gray, N Sprigg, P M W Bath, P Sørensen, E Lindenstrøm, G Boysen, P P De Deyn, P Friis, D Leys, R Marttila, J-E Olsson, D O’Neill, B Ringelstein, J-J van der Sande, A G G Turpie for the TAIST Investigators

Background: The medical care of patients with acute stroke varies considerably between countries. This could lead to measurable differences in mortality and functional outcome.

Objective: To compare case mix, clinical management, and functional outcome in stroke between 11 countries.

Methods: All 1484 patients from 11 countries who were enrolled into the tinzaparin in acute ischaemic stroke trial (TAIST) were included in this substudy. Information collected prospectively on demographics, risk factors, clinical features, measures of service quality (for example, admission to a stroke unit), and outcome were assessed. Outcomes were adjusted for treatment assignment, case mix, and service relative to the British Isles.

Results: Differences in case mix (mostly minor) and clinical service (many of prognostic relevance) were present between the countries. Significant differences in outcome were present between the countries. When assessed by geographical region, death or dependency were lower in North America (odds ratio (OR) adjusted for treatment group only = 0.52 (95% confidence interval, 0.39 to 0.71) and north west Europe (OR = 0.54 (0.37 to 0.78)) relative to the British Isles; similar reductions were found when adjustments were made for 11 case mix variables and five service quality measures. Similarly, case fatality rates were lower in North America (OR = 0.44 (0.30 to 0.66)) and Scandinavia (OR = 0.50 (0.33 to 0.74)) relative to the British Isles, whether crude or adjusted for case mix and service quality.

Conclusions: Both functional outcome and case fatality vary considerably between countries, even when adjusted for prognostic case mix variables and measures of good stroke care. Differing health care systems and the management of patients with acute stroke may contribute to these findings.

Outcome and the incidence of stroke vary between different countries.^1–3 Variations in case mix, including demographics (age, sex), and in the prevalence of vascular risk factors explain some of these differences.^4–6 Disparities in outcome may also result from variations in medical practice, such as the use of stroke units, which are known to reduce death and disability,⁷ and the treatment of acute stroke.⁸ Finally, different processes of care may also be important—for example, hospital admission rates for stroke differ across various countries.⁹

Within the Western world it might be expected that functional outcome corrected for case mix and service provision would be similar. However, evidence suggests that this may not be the case. In a study comparing outcome in 12 centres (22 hospitals) in seven European countries, outcome varied twofold when adjusted for case mix and the use of health service resources.⁸ Analysis of functional outcome in the international stroke trial showed similar findings.¹⁰ In both studies, outcome was worst in the United Kingdom.^8,10 In contrast, functional outcome was not significantly different between countries when corrected for case mix and health care resource use in the GAIN trial, despite significant variations in unadjusted case fatality.¹¹

In this study we compared case mix, clinical management, and functional outcome between 11 countries to assess this question further, using data from the tinzaparin in acute ischaemic stroke trial (TAIST).¹²