Ref (type)	Population	Outcome, Interventions	Results and statistical analysis	Effect size	Favours
All-cause hospital admissions
[66] RCT 3-armed trial	279 people, 70% with New York Heart Association (NYHA) functional class III	Rate of all-cause hospital admissions mean follow-up of 27 months with aspirin (300 mg/day) with warfarin Absolute results not reported	P <0.05 (aspirin v warfarin)	Effect size not calculated	warfarin
Admission to hospital for heart failure-specific causes
[71] RCT 3-armed trial	1587 people with NYHA class II to IV	Proportion of people admitted to hospital with worsening heart failure median follow-up of 21 months 116/523 (22%) with aspirin 89/540 (16%) with warfarin	P <0.02 (aspirin v warfarin) The RCT was terminated early because of slow enrolment (1587 people randomised rather than the planned 4500 people) and may have been underpowered to detect a clinically important difference Results should be interpreted with caution	Effect size not calculated	warfarin
[71] RCT 3-armed trial	1587 people with NYHA class II to IV	Proportion of people admitted to hospital with worsening heart failure median follow-up of 21 months 97/524 (19%) with clopidogrel 89/540 (16%) with warfarin	P = 0.38 (clopidogrel v warfarin) The RCT was terminated early because of slow enrolment (1587 people randomised rather than the planned 4500 people) and may have been underpowered to detect a clinically important difference Results should be interpreted with caution		Not significant