Table 2 Description of outcome variables, instruments, and cut-off points

Demographic and clinical characteristics of participants

Self-reported questionnaire

Demographic data (4 items)

▪ Age (in years)

▪ Sex

▪ Housing situation (living alone; with another person)

▪ Highest educational qualification

Clinical characteristics (4 items)

▪ Years of diagnosis of AF (in years)

▪ Experience in pulse self-palpation (yes, no)

▪ Presence of an electronic device for pulse measurement at home (yes, no)

▪ Regular implementation of pulse self-measurement at home (no, yes [multiple times a day; once per day; not daily, but multiple times per week; not every week, but multiple times per month; not every month, but multiple times per year])

T₁;

IG and UCG

Acceptability of intervention

Self-reported questionnaire

Assessment of appropriateness of the intervention (7 items)

▪ Usefulness of intervention (5-point Likert-scale, very useful–not useful)

▪ Importance of learning PSP when suffering arrhythmias (5-point Likert-scale, very important–not important)

▪ Liking of intervention (5-point Likert-scale, very much–not at all)

▪ Would participants recommend the intervention to others (yes, no)

▪ Appraisal of duration of intervention (too short, accurate, too long)

▪ Appraisal of difficulty level of intervention (5-point Likert-scale, very easy–very difficult)

▪ Appraisal of comprehensibility of content of intervention (5-point Likert-scale, very easy to understand–very difficult to understand)

T₁ (directly after intervention);

IG

The PSPAF intervention was considered acceptable to intervention participants when:

− ≥ 75% will rate the intervention partly to very reasonable

− ≥ 75% will rate the intervention partly to very important

− ≥ 75% will like the intervention partly to very much

− ≥ 75% will eventually or definitively recommend the intervention to others

− ≥ 75% will rate the duration of the intervention as accurate

− ≥ 75% will rate the difficulty level of the intervention partly to very easy

− ≥ 75% will rate the comprehensibility of the intervention as partly to very high

− ≥ 75% will rate the intervention partly to very helpful

− ≥ 90% did not experience any negative consequences related to the intervention

− ≥ 75% will rate implementation of the content of the intervention in daily life partly to very easy

− ≥ 75% will rate the likelihood of continuing a daily PSP twice a day as likely to very likely

− ≥ 75% will be considered adherent to PSP (> 80% of possible entries are filled out)

Self-reported questionnaire

Assessment of perceived effectiveness (1 item)

▪ Extent of how helpful the intervention was concerning dealing with AF in everyday life (5-point Likert-scale, very helpful–not helpful)

Assessment of perceived disadvantages (1 item)

▪ Negative consequences of intervention (yes, no, do not know)

Assessment of perceived suitability (1 item)

▪ Difficulty level of implementation of the content of the intervention in everyday life (5-point Likert-scale, very easy–very difficult)

Assessment of willingness of implementation (1 item)

▪ Likelihood of continuing a PSP twice a day (5-point Likert-scale, very likely–very unlikely)

T₂;

IG

Pulse diary

Assessment of adherence to PSP

Booklet consisting of a table with 35 lines and 10 columns. Each line represents a day and has two fields for indications of time of day, heart rate and regularity or irregularity of the measured pulse, respectively. A total of 70 pulse measurements could be recorded. An additional field was implemented for any specifics or further measurements.

T₁-T₂;

IG

Feasibility of the intervention

Field note form

Context/resources

Boxes assessing date, location, the existence of enough suitable rooms for delivering the intervention, and the presence of relatives during the delivery of the intervention

T₁ (directly after intervention);

IG

The PSPAF intervention was considered feasible when:

− The intervention can be delivered within 30 min,

− Fidelity to the intervention protocol will maintain at 85%

− Appropriate and enough room will exist in ≥ 85% of sessions

Audio recordings of intervention sessions

Fidelity of intervention implementation (3 items)

▪ Rating of clarity, distinctness, and comprehensiveness of language, and verbalizations of interventionist (each item, 4-point rating scale; not at all (0 points)–completely (3 points); single weighting)

▪ Rating whether the whole content and all components have been delivered as listed in the intervention manual (4-point rating scale, not at all (0 points)–completely (3 points), threefold weighting)

▪ Rating whether the whole content and all components have been delivered in the correct order as listed in the intervention manual (4-point rating scale, not at all (0 points)–completely (3 points), threefold weighting)

Time needed for delivering the intervention

▪ Assessed by the length of audio recordings (minutes, seconds)

T₁;

IG

Feasibility of research methods

Field note form (set up for every screening session)

Process of recruitment (7 criteria)

▪ Date

▪ Location

▪ Amount of screened individuals

▪ Amount of eligible individuals

▪ Amount of excluded individuals

▪ Amount of included individuals

Reasons for refusal

▪ Free text (indication was voluntary)

Stage of screening;Study coordinator

Research methods was considered feasible when:

− Recruitment of the target number of participants (n = 20) was accomplished within 4 months of beginning the study

− ≥ 80% of intervention participants attended the follow-up session (home visit)

− Attrition will be ≤ 15%

− ≥ 80% of data sets were completed

− Treatment contamination occurred in ≤15%

− ≥90% of participants perceived no or low burden of study participation

Checklist

Process of recruitment and documentation of eligibility criteria

Assessment of occurrence of each in- and exclusion criterion for every screened individual

Stage of screening;

Study coordinator

Field note form

Resources and management (5 criteria)

▪ Date

▪ Number of homes visits (on that day)

▪ Amount of driven kilometers (on that day)

▪ Amount of time (minutes) required for home visits and travel routes (on that day)

▪ Specifics (free text)

T₂;

IG and UCG

study assistant

Self-reported questionnaire

Assessment of treatment contamination (3 items)

▪ Participation in a training to learn PSP 3–4 weeks since inclusion in study (yes, no, do not know)

▪ Reading or watching media reports containing a training to learn PSP 3–4 weeks since inclusion in study (yes, no, do not know)

▪ Advice or training to learn PSP through family physician 3–4 weeks since inclusion in study (yes, no, do not know)

T₂;

UCG

Burden of study participation

Self-reported questionnaire

Burden of study participation (1 item)

▪ Grading the statement “I felt burdened by participating in this study.” (5-point Likert-scale, totally agree–totally disagree, translated into very high–no burden)

Subscale: if burden was perceived ➔ specification of kind of burden (3 items): psychological and/or physiological and/or financial burden

T₂;

IG and UCG

Capability of PSP

Checklist (for structured observation by study assistant)

Structure (2 items)

▪ PSP in rest (correct, wrong)

▪ Use of a clock with second hand (correct, wrong)

Process (5 items)

▪ Location of measurement (correct, wrong)

▪ Technique of measurement (correct, wrong)

▪ Duration of the measurement (correct, wrong)

▪ Stating determined value of the heart rate (no, yes [value in bpm])

▪ Stating determined value of the heart rhythm (no, yes [rhythmic, arrhythmic])

Outcome (2 items)

▪ Comparison of heart rate determined by the participant and heart rate determined by mobile ECG device (bpm) [verification of the value after consultation with a physician] (correct, wrong—heart rate was considered correct if heart rate measured by participants was ± 8 bpm in comparison to the ECG)

▪ Comparison of heart rhythm determined by the participant and heart rhythm determined by mobile ECG device [ECG evaluation by a physician, rhythmic/arrhythmic] (correct, wrong—heart rhythm was considered correct if the measurement of participants was equal to the evaluation of a physician)

T₂;

IG and UCG

A participant is seen as capable of PSP if all 9 components are correct or fulfilled, respectively.

Mobile ECG device

ME 90; Beurer GmbH, Ulm

T₂;

IG and UCG

Sign and symptom management

Vignettes (in written form)

V1—physiologic values, V2—mild pathologic values, V3— severe pathologic values

Sign and symptom management was rated “correct” or “wrong” by a study assistant by means of a standard solution for each vignette (Vs1-3).

T₂;

IG and UCG

Participants were considered being able to manage signs and symptoms if they solved the vignette correctly.