Measurement
Patients completed surveys about demographic characteristics and literacy levels, AF symptoms, and aspects of decision quality. Patients self-reported age, gender, race, ethnicity, preferred language, marital status, financial resources (“Do you have enough, not enough, or more than enough financial resources to make ends meet?”), educational level, and disability status. Health literacy was assessed using a widely used three-item health literacy screener developed by Chew and colleagues.24Subjective numeracy was assessed using the three-item Subjective Numeracy Scale developed by McNaughton and colleagues, with scores ranging from 0 to 18 with 18 representing excellent subjective numeracy.25
The University of Toronto AF Severity Scale (AFSS) was used to assess the severity of AF in terms of healthcare utilization, frequency and duration of AF episodes, and symptom severity.26The AFSS symptom subscale measures the severity of palpitations, shortness of breath at rest, shortness of breath during physical activity, exercise intolerance, fatigue at rest, lightheadedness or dizziness, and chest pain or pressure on a Likert scale of 0 to 5, with 5 being most burdensome. Total scores for the symptom subscale range from 0 to 35.
Surveys relating to aspects of SDM and decision quality included Controls-Preferences, Decisional Conflict, and Decision Regret scales. The Controls-Preferences Scale measures the degree of control an individual wants to assume when decisions are being made about medical treatment.27Five potential roles ranging from completely relinquishing control to clinicians to completely maintaining control over the decisions. The Decisional Conflict Scale measures the state of uncertainty about a certain treatment choice or course of action.28It includes 16 items and is reported as a total score reflecting overall decisional conflict and five subscales, all of which range from 0 to 100 with 100 representing extreme uncertainty about the best choice. Subscales include: “informed” about available options, risks, and benefits; “values clarity” about which benefits and risks are most important to an individual; “support” to make a decision with adequate advice but without pressure; “uncertainty” about the best choice for an individual, and perceptions of having made an “effective decision” based on perceptions of information and decision satisfaction. The Decision Regret Scale contains five items measuring distress or remorse after a medical decision.29Scores range from 0 to 100 with 100 representing high regret.