Quality of life at baseline: is assessment after randomization valid? The AVID Investigators. The Antiarrhythmics Versus Implantable Defibrillators

The purpose of this report is to examine whether differences existed between patients who completed a baseline quality of life (QoL) form before being informed about their randomized assignments versus those who completed it after knowing their randomization assignments. In the pilot phase of the Antiarrhythmics Versus Implantable Defibrillators (AVID) study (n = 200), 113 patients completed a baseline QoL battery prior to randomization (drug versus defibrillator), 49 additional patients completed this battery after randomization, and 38 patients did not complete this battery. Baseline demographic, clinical and QoL data were compared for these groups. Although the two groups with QoL data were not significantly different regarding various clinical and demographic characteristics, they did have significantly different QoL profiles. Patients with QoL collected before randomization had better overall QoL scores and mental health scores. These data suggest that patients with worse QoL may be less willing to complete a baseline QoL form in a timely manner or that knowledge of the randomization assignment may have an effect on QoL.