Participants
Between 08/2021 and 01/2022, patients were recruited for the study via the pacemaker and ICD outpatient clinic of the University Hospital Münster. The final patient sample included 92 patients in total, 38 (41%) with prior ICD shock experience and 54 (59%) without prior ICD shocks. 33 were offered to take part but did not complete a relevant number of questionnaires and did not indicate the vignette chosen and were hence excluded from the analysis. Patients with inappropriate shocks were not actively excluded, but there were no patients with inappropriate shocks in the analysis. The patients were made aware of the study through a poster placed at the entry of the outpatient clinic, which informed about the ongoing study and encouraged interested patient to ask for the questionnaire at the reception. Inclusion criteria were age ≥ 18 years, an implanted ICD with continuous follow-up (at least 3 follow-up visits) in our outpatient clinic, and information on the underlying arrhythmia leading to ICD shocks. Exclusion criteria were insufficient German language proficiency and severe psychiatric diagnoses (patients with psychotic or bipolar disorder, or drug addiction). Sample characteristics can be inspected in Table 1. All participants gave written informed consent. The study was performed in accordance with the Declaration of Helsinki and approved by the local ethics committee (Ethikkommission Westfalen-Lippe, Gartenstraße 210–214, 48147 Münster, Germany) prior to the beginning of the study (reference number: 2021-211-f-S).
Table 1 Baseline sample characteristics
|
Patients with experienced
ICD shock (n=38)
|
Patients without
ICD shock (n=54)
|
Difference statistic
|
Age in years (M±SD)
|
56.4±16.7
|
54.4±16.3
|
t = -0.581
|
Male sex
number, percentage
|
29 (76%)
|
37 (69%)
|
χ² = 0.669
|
Structural heart disease
number, percentage
ischemic
dilated
hypertrophic
congenital
|
34 (90%)
15 (39%)
6 (16%)
1 (3%)
8 (21%)
|
48 (89%)
14 (26%)
16 (30%)
4 (7%)
5 (9%)
|
χ² = 0.008
|
Secondary prevention
Aborted SCD
number, percentage
|
25 (66%)
18 (47%)
|
20 (37%)
17 (32%)
|
χ² = 7.379**
χ² = 2.388
|
Heart failure symptoms (NYHA ≥II)
number, percentage
|
20 (53%)
|
20 (37%)
|
χ² = 2.207
|
Psychiatric comorbidities
Psychiatric medication
number, percentage
|
10 (26%)
8 (21%)
|
5 (9%)
3 (6%)
|
χ² = 4.755*
χ² = 5.088*
|
Note. ICD = implantable cardioverter-defibrillator; SCD = sudden cardiac death; NYHA = New York Heart Association. * p <.05; ** p <.01.
Comparison Standard Selection
The case vignettes presented to the patients were fictitious and in analogy to studies by 25 and 26. There were four different vignettes to select reflecting two different levels of disease severity (mild, severe) and two types of coping (good, bad). Participants were asked to select one of the four vignettes they would like to read, based on brief descriptions. In particular the vignettes represented respectively a patient with mild disease and good coping (i.e., representing a comparison standard that is upward in terms of illness and upward in terms of coping, abbreviated UIUC standard), a patient with mild disease and bad coping (i.e. upward illness/downward coping, UIDC standard), a patient with severe disease and good coping (downward illness/upward coping, DIUC standard) and a patient with severe disease and bad coping (downward illness/downward coping, DIDC standard). The four brief descriptions were presented in a multiple-choice format on a single screen, requiring participants to select only one of them. The order of the options was randomized for each participant.
Comparison with the selected standard
Following standard selection, participants read the respective vignette and were asked to provide self-ratings relative to the standard (relief, anxiety, happiness about personal health, fear of deterioration, coping, focusing on similarity/differences) on a six-point Likert scale (1 = not at all; 6 = very much) using 7 items in total. The focus on similarities and the contrast between the standard and themselves was assessed by analogy with 25.
Current mood and subjective wellbeing
Current mood was assessed by a self-assessment manikin (SAM; Bradley & Lang, 1999; Sierra et al. 2021) 9-point scale (1 = very bad; 9 = very good) at the beginning of the survey as well as after the case vignette with the selection of standard. Current mood SAM scores were lost for seven participants (3 in the ICD + group) due to experimenter error.
Depression and anxiety levels
We assessed and quantified depressive symptoms with the Patient Health Questionnaire (PHQ-9, 29 and symptoms of anxiety with the Generalized Anxiety Disorder Scale (GAD-7, 30. The items ask for the occurrence of the respective symptoms in the last two weeks. The PHQ-9 uses 9 items and the GAD-7 uses 7 items, all of which are scored on a 4-point Likert scale based on the frequency of symptoms. For both questionnaires good psychometric properties have been reported 29–33.
Quality of life
The German version of the Short Form Health Survey (SF-12) questionnaire was used to assess the overall quality of life 34,35. The SF-12 makes use of 12 items, with 6 items using a 5-point Likert-scale, 2 items with a 3-point Likert scale and 4 dichotomous items. The SF-12 comprises two component scores, the Physical Component Summary (PCS) and the Mental Component Summary (MCS) with higher scores indicating a higher quality of life in the respective area. The scores range from 0–100 and are design to have a mean score of 50 and a standard deviation of 10 for a representative US population. Scores > 50 therefore lay above the average health status while scores < 50 lay below 34,36.
Florida Patients Acceptance Survey (FPAS)
The modified FPAS 37 was used to assess patient acceptance of the ICD implanted. The instrument uses 15 items and comprises four underlying latent variables. These are Return to Function (RTF), Device-Related Distress (DRD), Positive Appraisal (PA), and Body Image Concerns (BIC). All the 15 items are answered on a Likert-scale reaching from 1 (strongly disagree) to 5 (strongly agree). Subscales for each of the factors as well as a total sum score were calculated, with higher scores indicating higher levels of acceptance. An exception is the DRD subscale, where scores are separately calculated to indicate higher levels of distress. The scale has been evaluated extensively 38,39.
Coping Strategies and reaction to stress exposition
Coping behavior was assessed with the Coping Strategies Inventory Short-Form (CSI-SF 40). Sixteen items (5-point Likert scale) are used to assess 4 different factors of coping strategies, namely problem-focused engagement (PFE), problem-focused disengagement (PFD), emotion-focused engagement (EFE) and emotion-focused disengagement (EFD). Two overarching scales, total engagement (E) and total disengagement (D) are derived by summing the respective subscales (point range 4–20 for each subscale). The CSI-SF has been validated in various large cohorts in different languages, including German 41.
Frequency of upwards and downward comparisons
The frequency of different types of appetitive and aversive comparisons in relation to well-being and the engendered affect were assessed with the Comparison Standards Scale – Well-being (CSS-W; 22. The CSS-W uses 14 items to assess comparative thoughts in relation to the current well-being over the last three weeks by asking about the frequency of comparisons to different standards on a 6-point Likert scale (ranging from 0 to 5). The assessed types of comparison are social, temporal, counterfactual, and criteria-based. Seven items address appetitive comparisons and seven items address aversive comparisons. The two subscales are summarized separately using sum scores, with higher scores indicating more frequent comparison. Initial results suggest the CSS-W to be a valid assessment tool that relates significantly to mental health complaints 22.
Procedure
Participants were asked for their participation in the study during a routine visit at our outpatient ICD clinic. After receiving information about course and aim of the study and giving informed consent, participants completed the questionnaires (see Fig. 1). Participants were instructed to select one of four case vignettes they were most interested in reading. Afterwards they filled out the questionnaires in the order mentioned above and were thanked and debriefed. They did not receive compensation for completing the study. For overview of the order of measures see Fig. 1. Questionnaires were administered in pen-and paper format. The results of the questionnaires were complemented with medical data of the patients obtained from the patient data management system of our clinic.
Statistical analyses
Between-group effects, mainly focusing on mean or proportion differences between ICD + and ICD- (cf. H1-H4), were analyzed using independent-samples t-tests and analyses of (co-)variance (ANOVA) and chi-squared tests. Alpha was set at .05 (two-tailed) for all analyses. All statistical tests were performed using IBM® SPSS Version 28.