The ESPS was a multicenter study comparing the effect of the combination of dipyridamole 75 mg and acetylsalicylic acid 330 mg t.i.d. to placebo in 2500 patients (intention-to-treat analysis) and 1861 patients (explanatory analysis) in the secondary prevention of stroke or death after one or more attacks of TIA, RIND or stroke of atherothrombotic origin. End-point reduction was evaluated in two age groups, those not older than 65 years (1358 patients) and those who were older than 65 years (1142 patients). End-point reduction was significantly greater in patients with active therapy than in the placebo group in both age groups. Subgroup analyses with stroke as an end-point indicated that younger patients with TIA (< or = 65 years) had lower risk of stroke than those > 65 years or patients with stroke. The overall risk reduction was best in TIA patients > 65 years of age. The risk reduction with study medication was 40-50% in both sexes and in both age groups. Thus, age of the patient does not influence the efficacy of antithrombotic therapy. However, since these results are obtained from a secondary analysis of a subgroup of patients, the results may need confirmation by further studies.