Table 4.

Characteristics of included observational studies

Reference	Type of study	Aim	Treatment	Sample size and number of older participants	Follow-up	Outcomes
Burton 2006 [48]	Regional cohort-study	To measure the complication rates and adequacy of warfarin control in a cohort of patients with atrial fibrillation managed in primary care and to compare them with published data from controlled trials and community patients with atrial fibrillation not receiving warfarin.	ASA, warfarin INR 2–3, no antithrombotic therapy	N = 601, mean age 77 years. Subgroup analysis age ≥ 75 years.	5 years	Antithrombotic treatment, stroke or TIA, bleeding complications, death
Sam 2004 [59]	Community-based observational cohort-study	To determine the prevalence of warfarin and ASA use in atrial fibrillation.	ASA, warfarin, control	N = 393, men: mean age 72.5 years, women: mean age 79 years.	14 years	ASA and warfarin use, bleeding complication, cardiovascular events

ASA acetylsalicylic acid, MI myocardial infarction, INR international normalized ratio, TIA transient ischaemic attack