Lindsey Anderson, James PR Brown, Alexander M Clark, Hasnain Dalal, Henriette Knold K Rossau, Charlene Bridges, Rod S Taylor

Coronary heart disease (CHD) is the single most common cause of death globally. However, with falling CHD mortality rates, an increasing number of people live with CHD and may need support to manage their symptoms and improve prognosis. Cardiac rehabilitation is a complex multifaceted intervention which aims to improve the health outcomes of people with CHD. Cardiac rehabilitation consists of three core modalities: education, exercise training and psychological support. This is an update of a Cochrane systematic review previously published in 2011, which aims to investigate the specific impact of the educational component of cardiac rehabilitation. 1. To assess the effects of patient education delivered as part of cardiac rehabilitation, compared with usual care on mortality, morbidity, health-related quality of life (HRQoL) and healthcare costs in patients with CHD.2. To explore the potential study level predictors of the effects of patient education in patients with CHD (e.g. individual versus group intervention, timing with respect to index cardiac event). We updated searches from the previous Cochrane review, by searching the Cochrane Central Register of Controlled Trials (CENTRAL) (Cochrane Library, Issue 6, 2016), MEDLINE (Ovid), Embase (Ovid), PsycINFO (Ovid) and CINAHL (EBSCO) in June 2016. Three trials registries, previous systematic reviews and reference lists of included studies were also searched. No language restrictions were applied. 1. Randomised controlled trials (RCTs) where the primary interventional intent was education delivered as part of cardiac rehabilitation.2. Studies with a minimum of six-months follow-up and published in 1990 or later.3. Adults with a diagnosis of CHD. Two review authors independently screened all identified references for inclusion based on the above inclusion criteria. One author extracted study characteristics from the included trials and assessed their risk of bias; a second review author checked data. Two independent reviewers extracted outcome data onto a standardised collection form. For dichotomous variables, risk ratios and 95% confidence intervals (CI) were derived for each outcome. Heterogeneity amongst included studies was explored qualitatively and quantitatively. Where appropriate and possible, results from included studies were combined for each outcome to give an overall estimate of treatment effect. Given the degree of clinical heterogeneity seen in participant selection, interventions and comparators across studies, we decided it was appropriate to pool studies using random-effects modelling. We planned to undertake subgroup analysis and stratified meta-analysis, sensitivity analysis and meta-regression to examine potential treatment effect modifiers. We used the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach to evaluate the quality of the evidence and the GRADE profiler (GRADEpro GDT) to create summary of findings tables. This updated review included a total of 22 trials which randomised 76,864 people with CHD to an education intervention or a 'no education' comparator. Nine new trials (8215 people) were included for this update. We judged most included studies as low risk of bias across most domains. Educational 'dose' ranged from one 40 minute face-to-face session plus a 15 minute follow-up call, to a four-week residential stay with 11 months of follow-up sessions. Control groups received usual medical care, typically consisting of referral to an outpatient cardiologist, primary care physician, or both.We found evidence of no difference in effect of education-based interventions on total mortality (13 studies, 10,075 participants; 189/5187 (3.6%) versus 222/4888 (4.6%); random effects risk ratio (RR) 0.80, 95% CI 0.60 to 1.05; moderate quality evidence). Individual causes of mortality were reported rarely, and we were unable to report separate results for cardiovascular mortality or non-cardiovascular mortality. There was evidence of no difference in effect of education-based interventions on fatal and/or non fatal myocardial infarction (MI) (2 studies, 209 participants; 7/107 (6.5%) versus 12/102 (11.8%); random effects RR 0.63, 95% CI 0.26 to 1.48; very low quality of evidence). However, there was some evidence of a reduction with education in fatal and/or non-fatal cardiovascular events (2 studies, 310 studies; 21/152 (13.8%) versus 61/158 (38.6%); random effects RR 0.36, 95% CI 0.23 to 0.56; low quality evidence). There was evidence of no difference in effect of education on the rate of total revascularisations (3 studies, 456 participants; 5/228 (2.2%) versus 8/228 (3.5%); random effects RR 0.58, 95% CI 0.19 to 1.71; very low quality evidence) or hospitalisations (5 studies, 14,849 participants; 656/10048 (6.5%) versus 381/4801 (7.9%); random effects RR 0.93, 95% CI 0.71 to 1.21; very low quality evidence). There was evidence of no difference between groups for all cause withdrawal (17 studies, 10,972 participants; 525/5632 (9.3%) versus 493/5340 (9.2%); random effects RR 1.04, 95% CI 0.88 to 1.22; low quality evidence). Although some health-related quality of life (HRQoL) domain scores were higher with education, there was no consistent evidence of superiority across all domains. We found no reduction in total mortality, in people who received education delivered as part of cardiac rehabilitation, compared to people in control groups (moderate quality evidence). There were no improvements in fatal or non fatal MI, total revascularisations or hospitalisations, with education. There was some evidence of a reduction in fatal and/or non-fatal cardiovascular events with education, but this was based on only two studies. There was also some evidence to suggest that education-based interventions may improve HRQoL. Our findings are supportive of current national and international clinical guidelines that cardiac rehabilitation for people with CHD should be comprehensive and include educational interventions together with exercise and psychological therapy. Further definitive research into education interventions for people with CHD is needed.