Key messages
There is no clear evidence to suggest that social support or social network programmes help people with heart disease.
These programmes may produce some improvement in quality of life and blood pressure.
Our review suggests that, while social support or social network interventions may have potential to help people with heart disease, more high-quality, clearly reported trials are needed to prove any effectiveness.
What is heart disease?
The term 'heart disease' refers to a range of disorders affecting the heart, including: coronary heart disease (disease of the heart blood vessels); heart rhythm problems (arrhythmias, such as atrial fibrillation); heart infections; and congenital heart defects. Common symptoms of heart disease are chest pain (angina) and heart attack (myocardial infarction). Heart disease is a common cause of early death worldwide. Modern cardiac rehabilitation programmes are typically designed to address physical, mental, and social factors, and so to support people with heart disease in their day-to-day life.
Why might social support programmes help people with heart disease?
There is some evidence to suggest that low levels of social support and social isolation are linked to poor health for people with heart disease. Social network or social support interventions intentionally use social relationships to support healthy behaviours, and may involve partners, family members, friends, other peers, or caregivers. While some research suggests such programmes might contribute to improving health in people with heart disease, there has to date been no systematic review of the evidence.
What did we want to find out?
We wanted to find out whether programmes designed to help people with heart disease, which include a clearly described component of social support, might improve:
- deaths (from heart disease, or any other cause);
- hospital admissions;
- health-related quality of life.
We also wanted to find out if they improved any other related factors, such as mental health and well-being, and social isolation.
What did we do?
We searched databases for randomised controlled trials (RCTs) of social network or social support interventions for people with heart disease.
We compared and summarised the results of these studies and rated our confidence in the evidence, based on factors such as study methods and sizes.
What did we find?
We found 54 eligible studies involving 11,445 people with heart disease. We found wide variation in the kinds of interventions included in the review, in terms of what the programmes included, how and by whom they were delivered, and the clarity with which they were reported.
Most participants were male, with an average age ranging from 49 to 76 years. Studies included people with heart failure, post-myocardial infarction (heart attack), mixed heart disease, and post-revascularisation (procedures to widen blocked or narrowed arteries).
We found that social network or social support interventions had no clear effect on deaths, hospital admissions, or health-related quality of life.
What are the limitations of the evidence?
The reporting of factors such as what programmes included, how they were delivered, and how they were tested was highly variable. This made it hard to assess the evidence presented.
How up-to-date is this evidence?
The evidence is up-to-date as of August 2022.
We found no strong evidence for the effectiveness of such interventions, although modest effects were identified in relation to blood pressure. While the data presented in this review are indicative of potential for positive effects, the review also highlights the lack of sufficient evidence to conclusively support such interventions for people with heart disease. Further high-quality, well-reported RCTs are required to fully explore the potential of social support interventions in this context. Future reporting of social network and social support interventions for people with heart disease needs to be significantly clearer, and more effectively theorised, in order to ascertain causal pathways and effect on outcomes.
Globally, cardiovascular diseases (CVD, that is, coronary heart (CHD) and circulatory diseases combined) contribute to 31% of all deaths, more than any other cause. In line with guidance in the UK and globally, cardiac rehabilitation programmes are widely offered to people with heart disease, and include psychosocial, educational, health behaviour change, and risk management components. Social support and social network interventions have potential to improve outcomes of these programmes, but whether and how these interventions work is poorly understood.
To assess the effectiveness of social network and social support interventions to support cardiac rehabilitation and secondary prevention in the management of people with heart disease. The comparator was usual care with no element of social support (i.e. secondary prevention alone or with cardiac rehabilitation).
We undertook a systematic search of the following databases on 9 August 2022: CENTRAL, MEDLINE, Embase, and the Web of Science. We also searched ClinicalTrials.gov and the WHO ICTRP. We reviewed the reference lists of relevant systematic reviews and included primary studies, and we contacted experts to identify additional studies.
We included randomised controlled trials (RCTs) of social network or social support interventions for people with heart disease. We included studies regardless of their duration of follow-up, and included those reported as full text, published as abstract only, and unpublished data.
Using Covidence, two review authors independently screened all identified titles. We retrieved full-text study reports and publications marked ‘included’, and two review authors independently screened these, and conducted data extraction. Two authors independently assessed risk of bias, and assessed the certainty of the evidence using GRADE. Primary outcomes were all-cause mortality, cardiovascular-related mortality, all-cause hospital admission, cardiovascular-related hospital admission, and health-related quality of life (HRQoL) measured at > 12 months follow-up.
We included 54 RCTs (126 publications) reporting data for a total of 11,445 people with heart disease. The median follow-up was seven months and median sample size was 96 participants. Of included study participants, 6414 (56%) were male, and the mean age ranged from 48.6 to 76.3 years. Studies included heart failure (41%), mixed cardiac disease (31%), post-myocardial infarction (13%), post-revascularisation (7%), CHD (7%), and cardiac X syndrome (1%) patients. The median intervention duration was 12 weeks. We identified notable diversity in social network and social support interventions, across what was delivered, how, and by whom.
We assessed risk of bias (RoB) in primary outcomes at > 12 months follow-up as either 'low' (2/15 studies), 'some concerns' (11/15), or 'high' (2/15). 'Some concerns' or 'high' RoB resulted from insufficient detail on blinding of outcome assessors, data missingness, and absence of pre-agreed statistical analysis plans. In particular, HRQoL outcomes were at high RoB. Using the GRADE method, we assessed the certainty of evidence as low or very low across outcomes.
Social network or social support interventions had no clear effect on all-cause mortality (risk ratio (RR) 0.75, 95% confidence interval (CI) 0.49 to 1.13, I2 = 40%) or cardiovascular-related mortality (RR 0.85, 95% CI 0.66 to 1.10, I2 = 0%) at > 12 months follow-up. The evidence suggests that social network or social support interventions for heart disease may result in little to no difference in all-cause hospital admission (RR 1.03, 95% CI 0.86 to 1.22, I2 = 0%), or cardiovascular-related hospital admission (RR 0.92, 95% CI 0.77 to 1.10, I2 = 16%), with a low level of certainty. The evidence was very uncertain regarding the impact of social network interventions on HRQoL at > 12 months follow-up (SF-36 physical component score: mean difference (MD) 31.53, 95% CI -28.65 to 91.71, I2 = 100%, 2 trials/comparisons, 166 participants; mental component score MD 30.62, 95% CI -33.88 to 95.13, I2 = 100%, 2 trials/comparisons, 166 participants).
Regarding secondary outcomes, there may be a decrease in both systolic and diastolic blood pressure with social network or social support interventions. There was no evidence of impact found on psychological well-being, smoking, cholesterol, myocardial infarction, revascularisation, return to work/education, social isolation or connectedness, patient satisfaction, or adverse events.
Results of meta-regression did not suggest that the intervention effect was related to risk of bias, intervention type, duration, setting, and delivery mode, population type, study location, participant age, or percentage of male participants.