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A change of perspective? An explorative study on why patients may not subjectively report cognitive impairments after a cardiac arrest

  • Pauline van Gils
    Correspondence
    Corresponding author at: Doctor Tanslaan 12 6229 ET Maastricht, the Netherlands.
    Affiliations
    Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, Maastricht, the Netherlands

    Clinical Neurophysiology (CNPH), TechMed Centre, University of Twente, Enschede, the Netherlands

    Limburg Brain Injury Center, Maastricht University, Maastricht, the Netherlands
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  • Caroline van Heugten
    Affiliations
    Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, Maastricht, the Netherlands

    Limburg Brain Injury Center, Maastricht University, Maastricht, the Netherlands

    Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, the Netherlands
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  • Simone Sep
    Affiliations
    Adelante, Centre of Expertise in Rehabilitation and Audiology, Hoensbroek, the Netherlands

    Department of Rehabilitation Medicine, Maastricht University Medical Centre, Maastricht, the Netherland

    CAPHRI School for Public Health and Primary Care, Maastricht University, Maastricht, the Netherlands
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  • Véronique Moulaert
    Affiliations
    University of Groningen, University Medical Center Groningen, Department of Rehabilitation Medicine, Groningen, the Netherlands
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  • Jeannette Hofmeijer
    Affiliations
    Clinical Neurophysiology (CNPH), TechMed Centre, University of Twente, Enschede, the Netherlands

    Department of Neurology, Rijnstate Hospital, Arnhem, the Netherlands
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  • Jeanine Verbunt
    Affiliations
    Adelante, Centre of Expertise in Rehabilitation and Audiology, Hoensbroek, the Netherlands

    Department of Rehabilitation Medicine, Maastricht University Medical Centre, Maastricht, the Netherland

    CAPHRI School for Public Health and Primary Care, Maastricht University, Maastricht, the Netherlands
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Open AccessPublished:September 19, 2022DOI:https://doi.org/10.1016/j.resuscitation.2022.09.008

      Abstract

      Aim

      Cardiac arrest survivors are at risk of long-term cognitive impairment. Patients with cognitive impairments do not always have cognitive complaints and vice versa. Not reporting cognitive complaints could be caused by a lack of awareness. We hypothesized that caregivers report more cognitive failures than patients, indicating patients’ lack of insight into cognitive functioning.

      Methods

      This is a secondary analysis of the Activity and Life After Survival of Cardiac Arrest study on survivors of cardiac arrest and their caregivers. They were assessed at two weeks, three months, and one year after cardiac arrest. At each time point, the patient and the caregiver filled out the cognitive failure questionnaire (CFQ) regarding the patient. We analysed the correlation, intraclass correlation, and self-proxy discrepancy between patients and caregivers on the CFQ over time.

      Results

      One-hundred-and-nineteen cardiac arrest survivors (mean age = 60, 85 % male) and their caregivers were included. The CFQ scores of the patients and caregivers were equally low. The correlation (T1 r = 0.31; T2 r = 0.40; T3 r = 0.55) and intraclass correlation (T1 r = 0.48; T2 r = 0.56; T3 r = 0.71) between patient and caregiver increased over time.

      Conclusion

      This study does not support a lack of awareness of cognitive impairments by long-term cardiac arrest survivors. Future research may focus on alternative explanations for why patients have less cognitive complaints than expected based on the frequency of cognitive impairments. Possible explanations include a response shift.

      Keywords

      Introduction

      The survival rate of out of hospital cardiac arrest (OHCA) increased over the past decades.
      • Beesems J.
      • Stieglis R.
      • Koster R.
      Reanimatie buiten het ziekenhuis in Noord-Holland en twente: resultaten ARREST-onderzoek.

      Berdowski J, Waalewijn R, Koster R. Overleving na reanimatie buiten het ziekenhuis is sterk toegenomen: een vergelijkend onderzoek tussen eind 20ste en begin 21ste eeuw. Hart-en vaatziekten in Nederland najaar 2006, cijfers over ziekte en sterfte, 2006.

      • Savastano S.
      • et al.
      Positive trend in survival to hospital discharge after out-of-hospital cardiac arrest: a quantitative review of the literature.
      • Berdowski J.
      • et al.
      Global incidences of out-of-hospital cardiac arrest and survival rates: systematic review of 67 prospective studies.
      Therefore, it becomes increasingly important to investigate the long-term outcomes of cardiac arrest. One of these possible long-term outcomes is cognitive impairment resulting from hypoxic-ischemic brain injury.
      • Sandroni C.
      • Cronberg T.
      • Sekhon M.
      Brain injury after cardiac arrest: pathophysiology, treatment, and prognosis.
      • Cronberg T.
      • et al.
      Brain injury after cardiac arrest: From prognostication of comatose patients to rehabilitation.
      Approximately half of the OHCA survivors have enduring cognitive impairments.
      • Boyce L.W.
      • Goossens P.H.
      Rehabilitation after cardiac arrest: integration of neurologic and cardiac rehabilitation.
      • Zook N.
      • et al.
      Neurocognitive Function Following Out-of-Hospital Cardiac Arrest: A systematic review.
      • Moulaert V.
      • et al.
      Cognitive impairments in survivors of out-of-hospital cardiac arrest: a systematic review.
      Cognitive impairments refer to objectively identified impairments in cognition with neuropsychological tests. Cognitive complaints refer to subjective reports of experienced difficulty with cognitive functions. Not all patients who report cognitive complaints also have cognitive impairments and vice versa.
      • Boyce-van der Wal L.W.
      • et al.
      Cognitive problems in patients in a cardiac rehabilitation program after an out-of-hospital cardiac arrest.
      In contrast with most other types of brain injury, such as traumatic brain injury, Steinbusch et al. (2017) found that the percentage of patients with subjective cognitive complaints after OHCA is lower than that with objectively measured cognitive impairment.
      • Steinbusch C.V.
      • et al.
      Cognitive impairments and subjective cognitive complaints after survival of cardiac arrest: a prospective longitudinal cohort study.
      • Duits A.
      • et al.
      Cognitive complaints in the early phase after stroke are not indicative of cognitive impairment.
      • Stulemeijer M.
      • et al.
      Cognitive complaints after mild traumatic brain injury: things are not always what they seem.
      The reason for these relatively low levels of cognitive complaints in OHCA patients has not been clarified, yet. For possible future interventions, it is important to understand why patients with cognitive impairments do not always report them. One possible explanation is that patients lack awareness of their own cognitive impairments. Awareness deficits are a common consequence of brain injury.
      • Toglia J.
      • Kirk U.
      Understanding awareness deficits following brain injury.
      A common method to assess lack of awareness is to compare the patients’ assessment of their cognitive impairment with that of others (e.g. spouse or clinician), known as proxy measures.
      • Brown L.
      • et al.
      Awareness of deficit following traumatic brain injury: A systematic review of current methods of assessment.
      • Smeets S.M.
      • et al.
      Psychometric properties and feasibility of instruments used to assess awareness of deficits after acquired brain injury: A systematic review.
      We aimed to investigate whether the discrepancy between cognitive impairments and cognitive complaints can be explained by a lack of awareness of patients after cardiac arrest. We compared the subjective report of the patient with that of the informal caregiver on cognitive failures of the patient.
      • Moulaert V.R.
      • et al.
      Activity and Life After Survival of a Cardiac Arrest (ALASCA) and the effectiveness of an early intervention service: design of a randomised controlled trial.
      We hypothesized that the caregiver would report more cognitive failures than the patient. Such ‘self-proxy rating discrepancies’ would indicate that cardiac arrest survivors lack insight into their own cognitive functioning.

      Methods

      Study design

      This study is part of the Activity and Life After Survival of Cardiac Arrest (ALASCA) project [ISRCTN74835019], carried out between April 2007 and December 2010. This project was a multi-center prospective longitudinal cohort study. Two weeks, three months, and one year after cardiac arrest, patients received an assessment. This study complies with the Declaration of Helsinki and has been approved by the Medical Ethics Committee of Maastricht University Medical Center and the local committees of the participating hospitals.

      Participants

      Surviving patients were included within ten days after cardiac. Inclusion criteria were: age ≥ 18 years, living within 50 km of the hospital, and having sufficient knowledge of the Dutch language. Patients who had a life expectancy below three months and those who lived in residential or institutional care before the cardiac arrest were excluded. Caregivers could participate in the study if they were closely related to the patient (e.g. partner).

      Procedure

      Patients admitted to the hospital were asked to participate between three and ten days after the cardiac arrest. The patients and caregivers provided written informed consent or the caregiver was asked for provisional consent for the patient. The measurements were done two weeks (=T1), three months (=T2), and one year (=T3) after cardiac arrest. These were performed by trained research assistants. If the patient at T1 had insufficient awareness, the data was registered as missing.

      Assessment

      The Cognitive Failures Questionnaire (CFQ) was used to assess subjective cognitive failures.
      • Broadbent D.E.
      • et al.
      The cognitive failures questionnaire (CFQ) and its correlates.
      The patients filled out the CFQ to evaluate themselves (i.e. self-assessment). The CFQ was also filled out by the caregiver to evaluate the cognitive failures of the patient (i.e. proxy measure) (CFQ-C). This questionnaire consists of 25 items (e.g. “Forgetting appointments”). Each item can be scored on a scale from zero (never) to four (very often), resulting in a maximum score of 100. A CFQ discrepancy score was calculated by subtracting the CFQ score from the CFQ-C score. A score above zero on the discrepancy CFQ indicates that the caregiver reports more cognitive failures than the patient.

      Statistical analyses

      Statistical analyses were performed with SPSS version 25.

      IBM., SPSS (Version 25). 2016.

      Descriptive analyses were carried out to describe the socio-demographic and injury characteristics of the sample, and the scores on the CFQ. The data were tested for normality with the Shapiro-Wilk test. Medians and interquartile ranges were reported to give an accurate indication of the central tendency for non-normally distributed data. The CFQ discrepancy scores were tested with paired sample t-tests to take related observations into account. The degree of agreement between patients and caregivers on the CFQ was assessed by Pearson correlations and the intraclass correlation coefficient (ICC). The guidelines for interpretation of Cicchetti
      • Cicchetti D.
      Interreliability Standards in Psychological Evaluations.
      were used (<0.40 = poor; 0.40 – 0.59 = fair; 0.60 – 0.74 = good; 0.75 – 1.00 = excellent).

      Results

      Patient characteristics

      A total of 238 cardiac arrest patients were originally included in the ALASCA study. Part of the total sample was excluded from this analysis, because of participation in the intervention arm of a nested RCT (n = 97) and because of the absence of a caregiver (n = 22). This resulted in 119 patient-caregiver pairs in the current analysis (Fig. 1). Table 1 shows the socio-demographic characteristics of the sample. The majority of the patients were middle-aged married men. The average age of the caregivers was 55 years, the majority was female (85 %), and the patients’ partner (88 %). Cardiac arrest characteristics can be found in Table 2.
      Figure thumbnail gr1
      Fig. 1Note. T1 = two weeks after cardiac arrest, T2 = three months after cardiac arrest, T3 = one year after cardiac arrest. Flow diagram of participants included in the analysis.
      Table 1Socio-demographic characteristics of the patient sample before cardiac arrest (n = 119).
      Characteristicn (%) or mean (SD)
      Age in years60 (10)
       -Range37–86
      Sex (% male)101 (85)
      Marital status
       -Married/Partner102 (86)
       -Single/Divorced/Widowed12 (10)
       -Missing5 (4)
      Highest level of education
       -None1 (0)
       -Basic education22 (19)
       -Further education32 (27)
       -Higher education59 (50)
       -Missing5 (4)
      Living situation
       -At home114 (96)
       -Rehabilitation center1 (0)
       -Nursing home2 (2)
       -Missing2 (2)
      Employment status
       -Paid job57 (48)
       -Not working57 (48)
       -Missing5 (4)
      Table 2Cardiac arrest characteristics (n = 119).
      Characteristicn (%) or mean (SD)
      Out-of-hospital98 (82)
      Witnessed110 (92)
      CPR by:
       -Bystander59 (50)
       -Professional41 (34)
       - Missing or not applicable13 (16)
      Duration comatose state in days
      n = 87.
      2.4 (3)
       -Range0–19
      Time till ROSC in minutes
      n = 53.
      15.2 (13)
        -Range0–52
      Glasgow Coma Scale at admission
      n = 36.
      7 (5)
        -Range3–15
      Note. ROSC = return of spontaneous circulation.
      CPR = Cardiopulmonary resuscitation.
      a n = 87.
      b n = 53.
      c n = 36.

      Cognitive Failure Questionnaire

      CFQ scores of the patients were only significantly higher than those reported by their caregivers at T2 (Table 3). The correlation of the CFQ between patients and caregivers was r (67) = 0.31, p =.01 at two weeks, r (76) = 0.40, p <.001 at three months, and r (70) = 0.55, p <.001 at one year after cardiac arrest. The average measured ICC at two weeks post-arrest was 0.48 with a 95 % CI from 0.16 to 0.68 (F (68, 68) = 1.92, p =.004). At three months, the average measured ICC was 0.56 with a 95 % CI from 0.32 to 0.72 (F (77, 77) = 2.34, p <.001). At one year the average measured ICC was 0.71 with a 95 % CI from 0.53 to 0.82 (F (71, 71) = 3.39, p <.001). As such, ICCs were classified as fair at T1, fair at T2, and good at T3.
      Table 3Medians with interquartile ranges of the CFQ and correlations and ICCs between caregiver and patient on the CFQ, at 2 weeks, 3 months, and 1 year after cardiac arrest.
      T1 (n = 69)T2 (n = 78)T3 (n = 72)
      CFQMedianIQRp valueMedianIQRp valueMedianIQRp value
      CFQ2312–322113–292412–35
      CFQ-C207–301710–252310–34
      CFQ discrepancy−1−15–110.49−5−10–80.040−8–60.86
      T1 (n = 69)T2 (n = 78)T3 (n = 72)
      Correlations/ICCrp valuerp valuerp value
      Correlation caregiver and patient CFQ0.310.0090.40<0.0010.55<0.001
      ICC caregiver and patient CFQ0.480.0040.56<0.0010.71<0.001
      Note. T1 = 2 weeks after cardiac arrest; T2 = 3 months after cardiac arrest; T3 = 1 year after cardiac arrest; r = correlation coefficient; ICC = intra-class correlation coefficient; CFQ = Cognitive Failure Questionnaire by patient =; CFQ-C = Cognitive Failure Questionnaire by caregiver; CFQ discrepancy = CFQ-C – CFQ;

      Discussion

      In this study, we investigated whether caregivers of patients after cardiac arrest report more cognitive failures of the patients than the patients themselves. This would suggest a possible lack of awareness of cognitive impairment by cardiac arrest survivors, which could in turn explain the lower incidence of subjective cognitive complaints compared with objective cognitive impairments as found by Steinbusch et al. (2017)
      • Steinbusch C.V.
      • et al.
      Cognitive impairments and subjective cognitive complaints after survival of cardiac arrest: a prospective longitudinal cohort study.
      However, the results of this study could not confirm this hypothesis. Contrary to our expectations, caregivers and patients reported equally few cognitive failures.
      An alternative explanation of the low levels of cognitive complaints could be a response shift in patients after the cardiac arrest.
      • Wilson I.B.
      Clinical understanding and clinical implications of response shift.
      Response shift refers to a change in one’s evaluation of a situation or internal standards after the impact of disease. Over time, patients seem to (psychologically) adapt to their new circumstances. This explains why people with chronic disabilities report a higher quality of life than expected by outsiders, known as the “disability paradox”.
      • Albrecht G.L.
      • Devlieger P.J.
      The disability paradox: high quality of life against all odds.
      As described in the article of Forslund et al. (2017), patients can experience survival after cardiac arrest as a “second chance at life”.
      • Forslund A.S.
      • et al.
      A second chance at life: People's lived experiences of surviving out-of-hospital cardiac arrest.
      It seems that the survival of a life-threatening event can cause a change in perspective. The finding that quality of life of cardiac arrest patients does not differ from that of the general population supports this hypothesis.
      • van’t Wout Hofland J.
      • et al.
      Long-term quality of life of caregivers of cardiac arrest survivors and the impact of witnessing a cardiac event of a close relative.
      Feelings of gratitude may overshadow residual (cognitive) problems. Response shift can be measured with retrospective ratings.
      • Barclay-Goddard R.
      • Epstein J.D.
      • Mayo N.E.
      Response shift: a brief overview and proposed research priorities.
      Unfortunately, our data did not include such measurements.
      The agreement between patient and caregiver on cognitive failures increased over time from fair to good. Probably, over time and with experience, the patient and caregiver both get a better understanding of the level of functioning of the patient and thus increase in agreement.
      Some limitations need to be reported. First, in order to compare the CFQ values between patient-caregiver pairs, data from both parties were required. This resulted in more missing data on T1, T2, and T3, and led to a smaller sample size. Second, the CFQ was developed to measure cognitive failures in elderly people; more studies are needed to guarantee validity in cardiac arrest survivors. Third, although a self-proxy rating discrepancy is a commonly used method to assess awareness deficits, it cannot be guaranteed that proxy reports of caregivers accurately reflect the patients’ cognitive failures.
      • Smeets S.M.
      • et al.
      Psychometric properties and feasibility of instruments used to assess awareness of deficits after acquired brain injury: A systematic review.
      One’s opinion on cognitive failures of a partner could be subject to change, because of a possible response shift in the caregiver themself. Lastly, due to missing data the patient-caregiver pairs slightly change per timepoint, which could have affected the correlations.

      Conclusions

      This study does not support the hypothesis that patients after cardiac arrest lack awareness of tentative cognitive impairments. Future studies could investigate a possible response shift in relation to the relatively low incidence of subjective cognitive complaints in these patients.

      CRediT authorship contribution statement

      Pauline van Gils: Formal analysis, Writing – original draft, Investigation, Methodology, Data curation. Caroline van Heugten: Writing – review & editing, Supervision, Conceptualization, Methodology. Simone Sep: Writing – review & editing, Supervision, Conceptualization. Véronique Moulaert: Writing – review & editing, Resources. Jeannette Hofmeijer: Writing – review & editing, Supervision. Jeanine Verbunt: Writing – review & editing, Supervision, Conceptualization.

      Conflicts of Interest

      There are no conflicts of interest.

      Acknowledgements

      The authors thank Fleur Vermeer for contributing to the analysis of the data.

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