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Abstract
Objectives Current outcome measures in cardiac surgery are largely described in terms of mortality. Given the changing demographic profiles and increasingly aged populations referred for cardiac surgery this may not be the most appropriate measure. Postoperative quality of life is an outcome of importance to all ages, but perhaps particularly so for those whose absolute life expectancy is limited by virtue of age. We undertook a systematic review of the literature to clarify and summarise the existing evidence regarding postoperative quality of life of older people following cardiac surgery. For the purpose of this review we defined our population as people aged 80 years of age or over.
Methods A systematic review of MEDLINE, EMBASE, Cochrane Library, trial registers and conference abstracts was undertaken to identify studies addressing quality of life following cardiac surgery in patients 80 or over.
Results Forty-four studies were identified that addressed this topic, of these nine were prospective therefore overall conclusions are drawn from largely retrospective observational studies. No randomised controlled data were identified.
Conclusions Overall there appears to be an improvement in quality of life in the majority of elderly patients following cardiac surgery, however there was a minority in whom quality of life declined (8–19%). There is an urgent need to validate these data and if correct to develop a robust prediction tool to identify these patients before surgery. Such a tool could guide informed consent, policy development and resource allocation.
- GERIATRIC MEDICINE
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Strengths and limitations of this study
The studies included in our systematic review are largely retrospective in nature.
The majority of studies were of fair or poor quality as assessed by the US Preventative Services Task Force Quality Rating Criteria.
The studies did not provide sufficient quantitative data for meta-analysis.
Introduction
The two essential reasons to offer cardiac surgery are to improve quality of life (QoL) and prognosis. The latter probably becomes less important with increasing age. Useful preoperative risk calculators help surgeons estimate an individual's chance of death as a complication of planned cardiac surgery,1 but there is little to guide the likelihood of an improved QoL following surgery. This suggests that heart surgeons are falling short when seeking informed consent for their planned operations; especially so in the elderly where life's quality is likely to be valued over duration. This paper reviews the current literature on QoL following cardiac surgery in older participants. It provides a synthesis of evidence to identify gaps in our knowledge for new research, which is needed to inform patients as they consider consent for surgery and perhaps for health economists in resource allocation.
Methods
This systematic review was designed and reported following PRISMA criteria.2 Studies addressing QoL and functional status following cardiac surgery in patients aged 80 and over were identified by searching the electronic databases; MEDLINE (1950-22 February 2013, including articles in review stage), EMBASE (1980-22 February 2013) and the Cochrane Library (Issue 1 of 12 January 2013). A broad/sensitive search strategy was employed: truncated free-text searches within titles/abstracts/keywords were paired with exploded subject heading searches (MeSH and EMTREE). Search strategy/search terms used (TERMS IN CAPITALS are subject heading searches, ‘exp’ = exploded, MeSH terms given, equivalent EMTREE headings used in EMBASE): ‘“quality of life” OR qol’ in title/abstracts/keywords OR exp QUALITY OF LIFE/AND ‘(Heart* NEXT surg*) OR (heart* NEXT operat*) OR (cardi* NEXT surg*) OR (cardi* NEXT operat*)’ in title/abstracts/keywords OR exp CARDIAC SURGICAL PROCEDURES/OR THORACIC SURGERY/AND ‘8? NEXT yr? OR 8? NEXT year? OR 8?yr? OR 8?year? OR octagen* OR eighty NEAR/2 year? OR 9? NEXT yr? OR 9? NEXT year? OR 9?yr? OR 9?year? OR nonagen* OR ninety NEAR/2 year?’ OR AGED, 80 AND OVER in title/abstracts/keywords. All searches were completed on 22 February 2013. An advanced Google search, search of the National Health Service (NHS) Evidence portal (http://www.evidence.nhs.uk/), and the reference lists of articles were reviewed to check the rigour of the database search strategy. No language, publication date or publication status restrictions were imposed; however during the article review stage, manuscripts that were not in English language were excluded. Two reviewers (UA/MD) performed eligibility assessments independently in an un-blinded standardised manner. Disagreements between reviewers were resolved by consensus. Figure 1 details study selection.
PRISMA flow chart of study selection.
Data collection process
A data extraction sheet was pilot tested on the first 10 studies identified and refined accordingly. Information was extracted from each study on: (1) characteristics of study participants (2) type of operation and (3) QoL outcome measure employed. The quality of evidence was assessed using the US Preventative Services Task Force Quality Rating Criteria3 (USPSTFQR).
Quality of life assessment tools
The primary outcome measure was QoL of octogenarians (>80 years) following cardiac surgery. Assessment tools in the identified studies ranged from established QoL measures to bespoke questionnaires and objective assessments of independence, including physical functioning and activities of daily living. Of the validated tools used, the Medical Outcome Study Short Form-36 questionnaire (SF-36)4 and Karnofsky performance status score5 were most commonly employed. The SF-36 is validated for the assessment of QoL in multiple disease states including cardiovascular disease and elderly populations.6 Introduced in 19907 and upgraded to V.2 in 1996,8 the questionnaire consists of 36 questions covering 8 domains (physical functioning, role-physical, bodily pain, general health, vitality, social functioning, role-emotional and mental health), scaled from 0 to 100, a higher score indicates a better QoL. The domains are summarised into physical and mental health scores. The SF-12 is a shortened version covering the same eight domains. The Karnofsky score addresses functional impairment and was originally designed to assess overall performance status in patients with cancer. It is scored in 10% increments; from normal activity (100%), through to death at 0%. Other QoL and functional measures employed throughout the literature include; the Seattle Angina Questionnaire9 and Barthel Index,10 Nottingham Health profile,11 EQ-5D-3L12 Hospital anxiety and depression scale (HADS),13 Swedish health-related quality of life survey (SWED-QUAL)14 and the Minnesota Living with Heart Failure Questionnaire (MLHFQ).15
Results
Forty-four studies were identified that reported the QoL of octogenarians following cardiac surgery. Eight of the studies reported functional status as a measurement of QoL; these studies are included in our results (table 1). Twenty-three studies originated from Europe, 10 from the USA, 7 from Canada, 3 from Australia and 1 from Japan. The mean age of study participants ranged from 81 to 86.5 years and the study size from 21 to 1062 participants. Thirty-six of the 44 studies reported preoperative comorbidities but significant variation of conditions reported prevents meaningful comparison. The majority of studies were retrospective, however, nine studies followed patients prospectively allowing for direct comparison before and after surgery.
Prospective studies
Prospective studies
Nine prospective studies were identified, five studies employed the SF-36, three the Karnofsky score and one used a self-designed questionnaire (table 1). These studies included 780 patients, with an age range of 80–96. Length of follow-up varied from 3 months to 7 years. Those studies employing the SF-36 and one self-designed questionnaire16 found generally an overall improvement after surgery,17–19 with one study demonstrating no significant difference at 3 months.20 Domains that significantly improved varied between studies. Superior SF-36 scores were also found when comparing octogenarians to a younger cohort and an age-matched general population.21 The three studies using Karnofsky score22–24 found significant improvement in functional status following surgery.
Retrospective studies
Thirty-five retrospective studies were identified and five used multiple QoL tools (table 2). These studies included 8456 patients, with an age range of 80–99 and length of follow-up that varied from 6 months to 11.8 years. The tools employed in these studies included SF-36 in 10 studies, SF-12 in 3, self-designed questionnaires in 11, Karnofsky performance score in 4, SAQ in 4, Barthel index in 3, SWED-QAL 2, EQ-5D in 1, Nottingham Health Index in 1 and MLHFQ in 1. Eleven studies compared QoL following cardiac surgery to an age-matched cohort of the general population. Nine studies found comparable or superior QoL scores for the study population in most domains.25–33 One study found lower scores in the physical domains of the study population.34 Two studies reported poorer outcomes in women,35 ,36 however a third paper revealed the opposite.29 Three studies compared postoperative QoL in octogenarians against a younger patient cohort. While the first found superior SF-36 scores in the majority of domains37 the second found inferior SF-12 summary scores in the octogenarian cohort38 and the third found significantly lower physical function and the physical component summary scores in octogenarians.39 Two studies asked patients for their subjective comparison of QoL following surgery with that before. Both found a general improvement in QoL after surgery,40 although the second found a 33% reduction in physical fitness.41 The Seattle Angina Questionnaire was used to report QoL in three studies41–43 and reported that the majority of patients had a good functional status following surgery and were satisfied with their QoL. Eleven studies employed self-designed questionnaires, reporting an improvement in QoL in the majority of patients.44–54 However, in a small but significant minority QoL decreased following surgery. One study reported that QoL worsened in 12%,46 a second found a reduction in 15%,47 a third study reported that 17.8% felt their autonomy was worse following surgery48 and a forth reported that 13.2% felt their dependence on social support had increased. Interestingly, at 1 month following surgery 43% would not recommend surgery. This fell to 14% at 1 year.49 In one study multivariate analysis revealed female gender to be the only predictor of impaired autonomy50 and a second found poor left ventricular ejection fraction was an independent factor reducing QoL.44 Lower QoL scores in females were also demonstrated in one study employing the Nottingham Health profile54 Five studies employed the Karnofsky and/or Barthel Index to report the functional status of octogenarians following cardiac surgery and found an improvement in the majority of patients.55–59
Retrospective studies
Discussion
This systematic review was constructed according to the PRISMA guidelines. A comprehensive search strategy of the key medical electronic databases identified 44 studies. These included 9236 patients in total and all studies were retrospective but for 9. There was marked heterogeneity between studies. In general both prospective and retrospective series indicated an improvement in postoperative QoL for the majority of patients or a postoperative QoL comparable to an age-matched general population. Established tools used in measurement of QoL and functional status are validated and well designed. Self-designed questionnaires, though not validated, identified a significant minority in whom QoL fell after surgery (8–19%). Variable results may reflect different populations studied and individual centre's selection bias for surgery, as well as disparities in measurement methods. One key difference is the inclusion of a value for death, as overall results will differ if death is accounted for rather than excluded. The Karnofsky Performance Score and EQ-5D include a score for death. Only one of the seven studies employing these tools attributed a score for death.22 Another key factor affecting QoL after surgery is the time at which it was measured. It is inevitable that QoL worsens immediately following surgery and hopefully improves as the patient recovers. However, while there is evidence of improvement over the first postoperative year,49 a number of studies detailing QoL at multiple time points found no significant interval change.16 ,23 In our analysis there is insufficient evidence to describe the postoperative pattern of QoL. The key finding of this review is the apparent decrease in QoL in 8–19% of octogenarians following cardiac surgery. It is essential to validate this finding and to identify these patients so that at worst, harm to their well-being can be avoided and at best, we can better understand who these individuals are. A prediction model for postoperative QoL is required to allow clinicians to select and help patients better understand the consequences of their heart surgery and hence improve the quality of patients’ informed consent.
Conclusion
QoL following cardiac surgery in octogenarians improves in the majority of patients. However some 8%–19% appear to experience a fall in QoL and regret their decision to go forward with heart surgery. Considering the expanding numbers of elderly patients in contemporary practice, it is desirable to identify patients who will not enjoy an improvement in QoL. At a population level such work may also inform the appropriate provision of limited healthcare resources. A prediction model for postoperative QoL is required to help patients better understand the consequences of surgery, and hence improve the quality of their informed consent.
Acknowledgments
Adam Tocock and Jessica Wilkin.
References
Footnotes
Twitter Follow Andrew Cook at @ajcook
Contributors SL, UA contributed to the conception and design of the work and acquisition of data. UA, SL, MD are responsible for the initial drafting of the manuscript. AC, CB, SH, LV contributed to data analysis and interpretation, critical revision of the manuscript for important intellectual content and provided final approval of version to be published.
Competing interests None declared.
Provenance and peer review Not commissioned; externally peer reviewed.
Data sharing statement No additional data are available.