Defining Clinically Important Difference in the Atrial Fibrillation Effect on Quality-of-Life Score : Results From the Outcomes Registry for Better Informed Treatment of Atrial Fibrillation

Abstract

Background:

The Atrial Fibrillation Effect on Quality-of-Life (AFEQT) questionnaire has recently been validated to measure the impact of atrial fibrillation on quality of life, but a clinically important difference in AFEQT score has not been well defined.

Methods and Results:

To determine the clinically important difference in overall AFEQT (score range= 0 [worst] to 100 [best]) and selected subscales, we analyzed data in the Outcomes Registry for Better Informed Treatment of Atrial Fibrillation (ORBIT-AF) registry, a United States-based outpatient atrial fibrillation registry. AFEQT was assessed at baseline and 1 year in a subset of 1347 ORBIT-AF patients from 80 US sites participating in ORBIT-AF from June 2010 to August 2011. The mean change method was used to relate changes in 1-year AFEQT scores to clinically important changes in the physician assessment of European Heart Rhythm Association functional status (1 class improvement and separately 1 class deterioration). Clinically important differences and 95% CI corresponding to either a 1 European Heart Rhythm Association class improvement or deterioration were 5.4 (3.6–7.2) and −4.2 (−6.9 to −1.5) AFEQT points, respectively. Similarly, clinically important difference values were seen for a 1 European Heart Rhythm Association class improvement for the AFEQT subscales Activities of Daily Living and Symptoms: 5.1 (2.5–7.6) and 7.1 (5.3–9.0) AFEQT points, respectively.

Conclusions:

Based on the anchor of 1 European Heart Rhythm Association class change, changes in AFEQT score of + or −5 points are clinically important changes in patients’ health.

Clinical Trial Registration:

URL: https://clinicaltrials.gov . Unique identifier: NCT01165710.