Factors influencing health-related quality of life (HRQOL) in patients with implantable cardioverter defibrillator (ICD)

Review question/objective The objective of this systematic review is to identify factors influencing health-related quality of life (HRQOL) in patients who were admitted for first implantable cardioverter defibrillator (ICD) implantation and were followed up after implantation. The specific review questions are: 1) What are the factors influencing HRQOL of patients who had newly received their ICD implantation? 2) What factor(s) is/are positively or negatively influencing the parameter(s) of HRQOL of patients who had newly received their ICD implantation? Background Cardiovascular disease (CVD) remains a leading cause of death worldwide 1 and the second leading cause of death in Hong Kong since the 1960s 2. In 2004, CVD caused 17.1 million of deaths, approximately 29% of the global death1. Coronary artery disease (CAD) accounted for 7.2 million people who died from CVD worldwide in 2004 1 and 67.5% of CVD deaths in Hong Kong in 2008 3. Eighty percent of lethal arrhythmias, such as ventricular tachycardia (VT) and ventricular fibrillation (VF), are attributed to CAD and are the major causes of sudden cardiac death (SCD) 4, 5. For increasing the survival rate from SCD, implantable cardioverter defibrillator (ICD) therapy has been considered as an imperative treatment 6, 7. ICD is a cost-effective invasive medical treatment. An ICD is surgically implanted in a pouch under the skin of the chest, often just below the clavicle. It is a small battery-powered electrical generator to generate electric shocks to terminate malignant arrhythmias so as to reduce mortality resulting from SCD 6, 7.There are two major categories of ICD patients, primary or secondary prevention. People for the primary prevention are those who receive ICD without previous episode of life threatening arrhythmias or SCD commonly in heart failure patients; those for the secondary prevention are the survivals of SCD 8. ICD is also often used in patients with poor tolerance of anti-arrhythmic drug, such as Amiodarone 9. Indeed, with current advanced technology, ICD has been extended to apply in both atrial and ventricular arrhythmias, as well as to perform the function as biventricular pacemaker in patients with congestive heart failure 10. Since the approval of ICD by the Food and Drug Administration in 1985, the number of ICD recipients has been significantly increased. Despite its proven efficacy on increasing life expectancy, ICD may lower health-related quality of life (HRQOL) in many ICD patients 11, 12, 13. Quality of life (QOL) is an abstract concept which may not be fully well defined but it has unique meaning to an individual 14. WHO15 defined QOL as “an individual's perception of their position in life, in the context of the culture and value systems in which they live and in relation to their goals, expectations, standards and concerns” (p.1). Whereas, HRQOL refers “the physical, functional, social, and emotional well-being of an individual” (p.1) 16. HRQOL narrows the focus on health-related aspects which may be affected positively or negatively by medical treatment or healthcare intervention 17. Currently, HRQOL has been a significant area and has commonly used in healthcare research 18. Accordingly, instruments for measuring HRQOL have been developed diversely in different languages and widely used in various circumstances, including healthcare and nursing. Measuring instruments related to HRQOL can be generic and disease-specific. They are carefully designed as patient-reported questionnaires and well-validated. General HRQOL measuring instruments such as the Medical Outcomes Studies Short form-36 (the SF-36) which contains 36 questions with scoring in eight profiles of physical functioning and well being including physical functioning, role limitations due to physical problems, social functioning, bodily pain, general mental health, role limitations due to emotional problems, vitality, and general health perceptions 19. Disease-specific HRQOL measuring tools are more sensitive to some specific diseases. The Ferrans and Powers' Quality of Life Index - Cardiac III (QLI-CIII) is an example of the disease specific measuring instrument of QOL in cardiac patients. This instrument includes two parts with four domains of life situation (including health functioning, socio-economic, psychological/spiritual, and family) as well as the importance of these domains to subjects. There are 72 items (38 statements in each domain) scored with a 6-point Likert scale 20. Examining HRQOL has become more prevalent in ICD population. There have been numerous studies addressing impacts of ICD on HRQOL of ICD patients 21, 22, 23, 24, 25. Generic HRQOL instruments such as SF-36 19 and disease-specific HRQOL instrument, such as quality of life index- cardiac III (QLI-C3) 20, have commonly be used to measure HRQOL of patients with ICD. Some predicting factors, such as gender 26, 27, age 27, 28, and type of personality 29, have been identified to lower the HRQOL of patients with ICD. Vazquez, et al 27 conducted a survey to examine specific psychosocial concerns using the Florida Shock Anxiety Survey (FSAS), the multidimensional Fear of Death Scale (MFODS), and the subscale of body image concerns of Florida Patient Acceptance Survey (FPAS) in 88 women who had received ICD implantation. FSAS consisted of two subscales with ten items rated on a 5-point Likert scale from 1 (not at all) to 5 (all of the time), including consequences and triggering related to device shock. The total score of FSAS was ranged 10-50. FSAS was validated by Kuhl and colleagues30 in ICD patients and reported that the mean total score of the FSAS in ICD patients was 15.44 and the higher score indicated greater shock anxiety 30. The score of the MFODS was from 42 to 210, with the lower score indicating higher death anxiety 31. FPAS consisted of 18 items related to four subscales including return to function, device-related distress, positive appraisal, and body image concerns. Therefore, the total score of FPAS was 18-90 and the total mean score was 76.01. 32 The mean score of the body image concerns subscale of FPAS was 10.09, with the higher scores indicating greater body image distress 32. Vazquez and colleagues 27 reported that women who aged 50 or below were more likely to experience significantly higher risk of shock anxiety (score of the means of FSAS: 19; SD: 8.0; p=0.017), death anxiety (score of the means of MFODS: 29.5; SD 10.7; p=0.001), and body image (score of the means of the body image concern of FPAS: 25.8; SD: 28.2; p=0.04). They concluded that psychosocial factors might significantly lead to poor HRQOL associated with ICD shock and device concerns in younger female ICD patients. However, apart from gender and age, there may be potential risk factors worsening HRQOL in ICD patients. Pedersen and colleagues 29 conducted a prospective study to investigate the effect of type-D personality on HRQOL associated with ICD implantation using The Short Form 36 Health Survey (SF-36) at baseline and three months post ICD implantation. Patients with type-D personality tend to have more negative emotions contributing to poor HRQOL and higher mortality 33. They reported that patients with type-D personality were more likely to experience impaired HRQOL especially between the time of implantation and 3-month follow up [F (1,152 = 20.217; p<0.001)]. HRQOL of ICD patients may be worsened by various factors. Sears and his colleagues 25 examined predictors associated with HRQOL in 88 ICD patients at three intervals including initial assessment, short-term (6-9 months post ICD implantation) and long term (12-15 months post ICD implantation) follow-up. Social support, optimism, and depression were measured at the initial assessment; whereas, HRQOL, disease-specific HRQOL, and experience of ICD shock were evaluated at the both short-term and long-term follow-up. They found that psychological characteristics, experience of ICD shock, and social support could be factors of lowering HRQOL in patients with ICD. Therefore, factors influencing HRQOL of ICD patients can be complicated and diverse. However, incomprehensive evidence associated with factors influencing HRQOL in ICD patients may lead to misunderstanding and misinterpretation. Current studies have examined various interventions, such as psychosocial intervention 34, educational intervention 35, 36, and cognitive behavioural therapy/intervention 37, 38, associated with improving HRQOL in ICD patients and have presented with positive results on HRQOL in ICD patients. Most of them were designed with combinations of therapies and the methods of implementations were diverse and especially targeted on self care management and coping strategies associated with ICD shock to improve HRQOL through correcting the cognitive distortions and providing strategies to develop positive thoughts while living with ICD 38, 39. However, other significant factors influencing HRQOL may be neglected while designing interventions to improve HRQOL in ICD patients. The most effective intervention is based on understanding of the underlying causes and patient's individual preferences 40. Because ICD is a newly developed device but nursing contribution in this area is still insufficient, understanding the positive and negative factors influencing HRQOL in ICD patients plays an important role to direct and develop appropriate nursing intervention. It enables cardiac nurses to make vital decisions to address any misconception in terms of HRQOL, to promote implementation according to underlying factors to improve HRQOL, and to provide directions of future studies on potential factors that may positively or negatively influence HRQOL in patients undergoing ICD implantation. Therefore, it is important to conduct a systematic review to integrate scientific evidence addressing factors associated with lowering HRQOL in patients with ICD. Prior to initiating the review, a search of databases through Cochrane, JBI, and theses or dissertations revealed no systematic review conducted on factors influencing HRQOL in patients who were undergoing their ICD implantation. Preliminary database search with MEDLINE has been conducted to reveal the relevant articles on factors influencing HRQOL in patients with ICD. The detail of the search has been described in the “Search Strategy” section. Inclusion criteria Types of participants This review will consider 1) patients were 18 years old or above; 2) patients received their ICD implantation either for primary (those who receive ICD without previous episode of life threatening arrhythmias or SCD) or secondary prevention (those who are the survivals of SCD); 3) patients were admitted for ICD implantation for the first time. Types of intervention(s)/phenomena of interest This review will consider studies that investigate factors influencing HRQOL in patients who received their ICD implantation the first time. Types of studies This review will consider all randomized controlled trials (RCTs) that examined factors influencing HRQOL in patients who were undergoing ICD implantation. In the absence of RCTs, other research designs, such as non-randomized controlled trials, prospective studies, descriptive studies, case control study, and cohort observational studies, will be considered to enable the identification of current best evidence on factors influencing HRQOL of ICD patients. This review will consider studies 1) which were published from 1985 onwards because ICD was approved by Food and Drug Administration (FDA) in 1985; 2) which examined HRQOL or QOL (including either one of physical, mental/psychological, and social functioning) as an outcome measure in ICD patients 3) using quantitative instruments to measure HRQOL or QOL; 4) which investigated factor(s), such as age, gender, psychological distress, or shock generated from ICD to terminate life-threatening rhythm and its frequency, influencing HRQOL or QOL and showed the correlation(s) between factor(s) and HRQOL or QOL using data analytic methods such as ANOVA, MANOVA, t-test, multiple regression. Exclusion criteria This review will exclude studies which consist of 1) Patients who had received ICD re-implantation; 2) Patients with mental or cognitive disorders; 3) Patients who had their ICD implantation at abdomen; 4) Patients who received the ICD with other interventions, such as resynchronization therapy (RCT) and antitachyarrhythmic pacing (ATP) because those therapies acted as variables to alter the perspectives of HRQOL of ICD patients; 5) Studies which were literature reviews, systematic reviews, clinical guidelines or recommendations; editorials or reports of expert opinions; 6) Studies were conducted to evaluate the effectiveness of an intervention on HRQOL or QOL in ICD patients because the intervention could act as a variable to alter the perspectives of HRQOL of ICD patients; 7) Studies examining the effectiveness of an intervention or factors influencing the effectiveness of an intervention on health related quality of life in ICD patients. 8) Studies were conducted to validate assessment tools for HRQOL or QOL; and 9) Studies were not published in English or Chinese. Search strategy The search strategy aims to identify factors influencing HRQOL from both published and unpublished studies. The studies published in English and Chinese will be searched. A three-step search strategy will be employed in each component of this review. The initial limited search of MEDLINE will be undertaken followed by an analysis of text words contained in the title and abstract, and of the index terms used to describe the article. Secondly, the extensive search will start with searching English studies utilizing keywords. ‘ICD’, ‘AICD’, ‘implantable defibrillator’, ‘health related quality of life’, ‘quality of life’, ‘quality of living’, ‘quality of health’, ‘quality of well being’, ‘daily activities’, activities of daily living’, ‘physical health’, ‘psychological health’, ‘mental health’, ‘social health’, ‘factors’, ‘determinants’, predictors’, ‘predicting factors’, ‘indicators’, ‘age’, ‘gender’, ‘psychological distress’, ‘anxiety’, depression’, ‘shock’, and “severity of illness’. The keywords will be translated into Chinese and searched relevant literatures through Chinese databases. The titles and abstracts will be assessed by two independent reviewers against the inclusion and exclusion criteria. For all studies that meet the inclusion criteria will have the full texts retrieved. If the titles and abstracts are not conclusive, full text of the article will be evaluated against the inclusion criteria by two reviewers. Thirdly, Google Scholar and the reference lists of all identified relevant articles will be searched for other additional sources of studies. The search strategy will be limited from 1985 to present because the approval of ICD by the FDA was in 1985. Electronic databases to be searched for English studies will include: 1) MEDLINE 2) CINAHL Plus (1985 -August 2010) 3) ProQuest 5000 (1985 -August 2010) 4) Current Controlled Trials 5) ISI Web of Knowledge 6) British Nursing Index and Achieve (1994-August 2010) 7) PsycINFO (1985-August 2010) 8) SCOPUS (1985-August 2010) 9) ERIC (1985-present) 10) Cochrane Library 11) JBI COnNECT+ 12) EMB Reviews: Cochrane Database of Systematic Reviews 13) EMBASE (1985-August 2010) 14) Global Health 15) Health Sciences: A SAGE Full Text Collection (1985-August 2010) Databases to be searched for Chinese studies will include: 1) China Journal Net 2) Chinese Biomedical Literature Database 3) Chinese Medical Current Content 4) HyRead (1985-August 2010) 5) Taiwan Electronic Periodical Service 6) China Medical Academic Conference (1994-August 2010) 7) Digital Periodicals (1998-August 2010) 8) National Science and Technology (1985 -August 2010) The search of unpublished studies or grey literature will utilize the following sources: 1) PreMEDLINE 2) Index to Theses 3) ProQuest Dissertation and Thesis 4) MEDNAR 5) The Networked Digital Library of Theses and Dissertations 6) WanFang Data 7) Chinese Dissertation Database 8) Agency for Healthcare Research and Quality 9) Academic Achieve On-line 10) Digital Dissertation Consortium 11) Grey Literature Report (via New York Academy of Medicine) 12) Lancashire Care Library and Information Service 13) National Library of Medicine Gateway Initial search strategy MEDLINE (OvidSP) implantable defibrillator.mp. or exp Defibrillators, Implantable/ ((internal or implantable) adj defibrillator).mp. internal defibrillators.mp. implantable defibrillator.mp. cardiac.mp. cardi$.mp. #1 or#2or #3 or #4 #5 or#6 #7 and #8 quality of life. mp. or exp ?Quality of Life?/ quality of living.mp quality of health.mp quality of well being.mp. health related quality of life.mp HRQOL.mp. QOL.mp. exp ?Activities of Daily living?/ or daily activities.mp Physical.mp. Psychological.mp. Psycho$.mp. Mental.mp. Social.mp. Sexual.mp. #18 or #19 or #20 or #21 or #22 or #23 exp ?Health?/or health.mp. #24 and #25 #10 or #11 or #12 or #13 or #14 or #15 or #16 or #17 #26 and #27 Factor$.mp. Risk factor$.mp. or exp Risk Factor/ Determinant$.mp. Reason$.mp. Cause$.mp. #27 or #28 or #29 or #30 or #31 or #32 Age factors/or age.mp gender.mp.or exp Gender Identity/ exp personality/ or personality.mp. shock$.mp. severity of illness.mp. severity adj illness/ or Depress$.mp. exp Anxiety/ or anxi$.mp. psychological distress.mp. personality.mp. Type adj personality.mp. ((duration/ or diagnosis) adj implantation).mp. Ejection fraction.mp. EF.mp. exp Arrhythmia, Cardiac/ or arrhythmi$.mp. #35 or #36 or #37 or #38 or #39 or #40 or #41 or #42 or #43 or #44 or #45 or #46 or #47or #48 or #49 Hospital Anxiety and Depression Scale.mp. General Health Questionnaire.mp. (SF-36/or SF-12).mp. WHOQOL.mp. (FSAS/ or FPAS/).mp. #51 or #52 or #53or #54 or #55 clinical trial.mp. or exp Clinical Trial/ randomized.mp. random$.mp. rct or rct$ (control$ adj3 (stud$ or trial$)).mp. ((prospective/or descriptive/ or case control) stud$).mp. comparison stud$/ comparison group$.mp. #57 or #58 or #59 or #60 or #61or #62 or #63 #28 and #56 #9 and # 50 and #65 Limit #43 to (English language and humans and all adult (19 plus years)) #64 and #67 Assessment of eligibility All identified potential studies will be assessed for relevance based on the title and abstract of the study. Additional relevant studies will be assessed for relevance based on the title of study from reference list of each identified relevant study. The first and second reviewers will independently assess all identified abstracts using the Study Eligibility Verification Form (Appendix A). If the title and abstract are not conclusive, full text of the study will be obtained for further analysis. The two reviewers will make decision according to the inclusion and exclusion criteria of the study. Any discrepancies between them will be resolved by discussion and consultation with the studies will be into a Full text will be obtained for all studies for and data Assessment of quality All relevant quantitative studies will be assessed by two independent reviewers for quality using the from the of Assessment and Review Any that between the two reviewers will be resolved through assessment and discussion with the Data Data will be from quantitative studies using the of the of Assessment and Review (Appendix The data will that are significant to the review and questions such as of and their study study and the number and for and Any discrepancies between reviewers will be resolved through or with the Data If appropriate with results from quantitative studies will be in using All results will be to data and mean and their intervals will be for analysis. will be assessed using the is not the will be presented in of interest of