Study designs of evaluations included in the review
The authors aimed to identify clinical trials. Four of the identified studies were reported to be randomised double-blind trials, 3 of which were placebo-controlled. The design of one study was not fully described.
Specific interventions included in the review
Studies of the combined use of aspirin and dipyridamole were eligible for inclusion in the review. In the included studies, a range of doses and dose frequencies of aspirin and dipyridamole were used: aspirin 25 mg twice daily (bid) to 325 mg four times daily, plus dipyridamole 75 mg three times daily (tds) to 200 mg bid. This combination was compared with aspirin alone, dipyridamole alone or placebo.
Participants included in the review
Studies of patients who had suffered a first stroke or transient ischaemic attack (TIA) were to be included. In the 5 included studies, the mean age of the participants ranged from 55.5 to 66.7 years and the proportion of males ranged from 58 to 76.3%. Ninety-one per cent of the patients in one trial were white; the race was unspecified in the other studies. The mean blood-pressure was reported in 2 studies as 150 (plus or minus 20)/90 (plus or minus 12) mmHg and 157.2/92.4 mmHg. Where reported, alcohol use occurred in 5.6 to 43.0% of the patients and cigarette smoking in 24.1 to 64.1%. The qualifying event was a complete stroke in 60.1 to 83.9% of the patients, TIA in 16.1 to 94.0%, and 2 studies reported reversible ischaemic neurological deficit (RIND) in 6.5 and 47.3% of the patients. The time from the qualifying event to study enrolment varied from less than 1 month to 1 year. The participants had one or more of the following concurrent diseases: arrhythmias, cardiac failure, diabetes, hypercholesterolaemia, hypertension, ischaemic heart disease and peripheral vascular disease.
Outcomes assessed in the review
The outcome specified by the inclusion criteria was recurrent stroke. In the review, the studies reported on fatal and nonfatal stroke, death from other causes, stroke, retinal infarction, TIA and RIND.
How were decisions on the relevance of primary studies made?
The authors do not state how the papers were selected for the review, or how many of the reviewers performed the selection.