SYNTHESIS OF THREE DATA SOURCES TO DETERMINE INDEPENDENT VARIABLES IN AN ONLINE FACTORIAL SURVEY OF IMPLANTABLE CARDIOVERTER DEFIBRILLATOR DEACTIVATION DECISIONS

Purpose: To identify the key factors that impact on clinical decision-making concerning the deactivation of an implantable cardioverter defibrillator (ICD) at end-of-life. An ICD is cornerstone in the treatment of life-threatening arrhythmias, although there is growing concern that dying patients are receiving multiple futile shocks.

Method(s): Sequential exploratory mixed methods design incorporating two phases.

• Phase One: Data from a systematic review of literature, qualitative exploration and a retrospective case note review were synthesised to conceptualise nine independent variables (IVs). 
• Phase Two: These IVs were embedded within six randomised vignettes of an online factorial survey disseminated to UK and Irish professionals. 

Result(s): Three themes emerged from the literature, which were validated and enriched through qualitative exploration. Data from the retrospective case note review provided clinically-specific factors, ensuring vignettes addressed real-life scenarios. The factorial survey had a full data-set with 534 randomly-assigned vignettes completed by 89 professionals (22 Cardiologists, 57 Nurses and 10 Clinical Physiologists). Patient variables associated with the likelihood of professionals’ discussing ICD deactivation included heart failure severity (NYHA IV), co-morbidities and the number of shocks experienced by the patient. Professional characteristics of time in current post and previous engagement in a deactivation discussion impacted on confidence with clinical decision-making

Conclusion(s): The factorial survey, utilising vignettes with characteristics randomly assigned, is a method of increasing importance in the study of decision making. This study was innovative in that three data sources were synthesised effectively to identify and conceptualise the IVs for vignettes in the factorial survey. Data synthesis was systematic, rigorously conducted and transparent thereby extending the factorial survey methodology as well providing direction to improve end-of-life care for patients with an ICD