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.