Reviewer's report
Title: Birmingham Atrial Fibrillation Treatment of the Aged study (BAFTA): a randomised controlled trial of warfarin versus aspirin for stroke prevention in the management of atrial fibrillation in an elderly primary care population Authors: Dr Jonathan WF Mant (j.w.mant@bham.ac.uk) Suzanne H Richards (suzanne.richards@pms.ac.uk) Prof Richard Hobbs (f.d.r.hobbs@bham.ac.uk) Dr David A Fitzmaurice (d.a.fitzmaurice@bham.ac.uk) Gregory YH Lip (g.y.lip@bham.ac.uk) Ellen T Murray (e.t.murray@bham.ac.uk) Miriam V Banting (m.v.banting@bham.ac.uk) Kate Fletcher (k.fletcher@bham.ac.uk) Joy Rahman (j.rahman@bham.ac.uk) Teresa A Allan (t.a.allan@bham.ac.uk) James P Raftery (j.p.raftery@bham.ac.uk) Stirling Bryan (s.bryan@bham.ac.uk) Version: 1 Date: 30 Jun 2003 Reviewer: Patricia Howard Level of interest: A paper whose findings are important to those with closely related research interests Advice on publication: Accept after discretionary revisions Compulsory Revisions: The study design appears to be appropriate to address the stated research question. However, I have the following concerns: 1. Your inclusion/exclusion criteria do not address individuals with transient AF. Since an ECG within 2 y is sufficient for inclusion, how will you rule out those cases of transient or one time AF for example after surgery? In addition, it appears that you are including both chronic and paroxysmal AF. If so, you should at least state this fact and consider addressing this in your discussion. 2. Are you excluding patients with AF who are already on warfarin or aspirin at the time of identification? Please clarify this point in your methods. 3. It appears that the first follow-up visit is at 3 months. How closely will the INRs be monitored and adjusted during this initial period? Your methods should more clearly describe how warfarin doses will be adjusted and monitored. 4. How will you define major and minor bleeding events? This should be clarified in the methods section. 5. Please clarify in the methods whether you will separately analyze those individuals included in the trial who require chronic NSAID use for other reasons? 6. Figure one nicely outlines the trial design, however some key information is missing:
a. How will warfarin dosing be initiated and titrated and how often will the INR be monitored? Who will do the monitoring? In other words describe the follow-up more completely. b. The terms incident case group, case note group and opportunistic group may not be clear to many readers. Consider defining these terms in a footnote. c. Add the aspirin dose to the figure since it is fixed. 7. Minor point on Writing Style: Whenever you refer to patient age, please include the word "years" or the appropriate abbreviation. Discretionary Revisions 1.Will you be able to report average number of INRs in range? If you can, I would add this to your methods. Knowing the extent to which patients are in the therapeutic range will be very important to interpreting your findings. If you cannot do this, it will need to be identified as a limitation in later discussion of the results. 2.In your cost analyses, will you include hospitalization costs associated with complications (e.g. readmit for bleeding)? Overall, the article is easy to read and well organized. I have no additional suggestions. Competing interests: None declared.