2 Evidence gaps

This section describes the evidence gaps, why they need to be addressed and their relative importance for future committee decision making.

The committee will not be able to make a positive recommendation without the essential evidence gaps (see section 2.1) being addressed. The company can strengthen the evidence base by also addressing as many other evidence gaps (see section 2.2) as possible. This will help the committee to make a recommendation by ensuring it has a better understanding of the patient or healthcare system benefits of the technology.

2.1 Essential evidence for future committee decision making

Clinical effectiveness

The impact of the technologies on intermediate and longer-term clinical outcomes in comparison with conventional cardiac rehabilitation is uncertain. Further evidence is needed to assess clinical effectiveness of the technologies both when they are used alongside conventional cardiac rehabilitation, and when used alone in place of conventional cardiac rehabilitation. The effect on clinical effectiveness of changing from paper to digital manuals is also uncertain.

Evidence on intermediate clinical outcomes should include:

patient-reported outcomes
health-related quality of life
exercise capacity or performance
cardiovascular risk profile
psychological wellbeing
nutrition status
medical adherence
behavioural change.

Further evidence is needed on the longer-term clinical effects (for example secondary cardiac events, hospital readmissions, referrals to specialist services and clinic visits). Information on the longevity of any clinical benefits will provide a clearer indication of the accumulated benefits over time and support cost-effectiveness modelling. Follow ups should include the duration of the cardiac rehabilitation program (which is technology specific) and at least 12 months later, but ideally 18 months.

The committee noted significant variation in the measurements of outcomes, and highlighted that these should, ideally, be standardised. Suggested measurements for the clinical outcomes are detailed in section 3.4.

Resource and service impact

Early cost-effectiveness modelling was driven by cost savings from a reduction in face-to-face cardiac rehabilitation sessions. Further evidence is needed to support these analyses, particularly around the resource costs and system impacts of using the technologies compared with conventional cardiac rehabilitation. This should include overall costs, and the broader resource impact that cardiac rehabilitation has on the healthcare system over at least 12 months after using the technology, ideally 18 months.

Key areas that will help to address this evidence gap are:

healthcare resource use associated with the technologies and NHS standard care, for example:
- primary, secondary and community care appointments
- hospital visits, admissions and readmissions related to cardiac events
implementation costs, for example, set up and training costs, and staff time needed to support the service
technology costs including licence costs.

Engagement and acceptability

More evidence on intervention uptake, adherence, completion and attrition rates (including reasons for stopping therapy) will support future cost-effectiveness modelling and help the committee assess the real-world uptake of the technologies. Evidence on user-reported outcomes including user preferences, usability and acceptability will also help assess how acceptable the technologies are for people who use them.

2.2 Evidence that further supports committee decision making

Uptake in different subgroups

The impact of the technologies on uptake of cardiac rehabilitation in different subgroups is unknown. Evidence is needed for user subgroups who may benefit from the remote and digital delivery of cardiac rehabilitation programs. These may include:

People who may not be able to attend daytime in-person cardiac rehabilitation sessions (for example, people with work or caring responsibilities or people living in rural communities with long travel times to clinics)
Subgroups in which current uptake of cardiac rehabilitation is low (for example women, people under 65 years, people from deprived areas, people whose first language is not English, and people from Black, Asian and other ethnic minority groups).