Measuring care dependency in heart failure

This invited commentary refers to ‘Psychometric testing of the Care Dependency Scale in patients with heart failure and their caregivers’, by A. Durante et al. https://doi.org/10.1093/eurjcn/zvad117. Heart failure is a chronic condition affecting 1–2% of the general adult population in developed countries.1 Though survival has greatly improved, the burden of managing everyday life with the condition remains very high.2,3 Hence, many people living with heart failure rely on help from partners, family, or friends.4,5 These informal, unpaid, caregivers help with self-care activities such as monitoring dietary intake, medication management, and participation in physical activity, all important for reducing exacerbations.2 Common symptoms of heart failure include dyspnoea, fatigue, oedema, and weakness making everyday tasks difficult to complete with informal caregivers again stepping in to support or complete the tasks.6 The absence of caregiver support has been associated with increased re-hospitalizations and mortality for people with heart failure.7 However, the role of caregiving can come with many physical, emotional, and economic consequences.2 Caregivers report anxiety, depression, fatigue, and social isolation with the demands of caregiving limiting their ability to work, sleep, and socialize.4,5,8,9 Thus, to some extent, the burden of heart failure is born by both the patient and their caregiver. Essential to this patient/caregiver relationship or ‘dyad’ is the requirement of most self-care or everyday tasks to be completed together.10 Successful dyad collaboration is dependent on many factors but a key component is likely to be a common understanding of what the care needs are and to what extent help is needed.11 The recent study published in the European Journal of Cardiovascular Nursing by Durante et al.12 investigates the use of the Care Dependency Scale (CDS) as a novel way to gain insight into the perspectives of both patients and caregivers in the specific area of care dependency. The CDS measures the subjective need for support required to compensate for a deficit in self-care in 15 physical and psychosocial domains.12,13 Proxy completion of patient-reported outcome measures is commonly used where self-reporting of health status is not considered possible. This might be when a patient is physically unable to respond, or their responses might be thought unreliable as in the case of cognitive impairment.14,15 Interestingly, rather than using the proxy version only for those patients who could not complete the CDS themselves, all the heart failure patients and their informal caregivers in the study completed the CDS independently. Durante et al.12 found the CDS and proxy CDS had acceptable validity and reliability and proposed that the results from the proxy CDS could be used by health professionals when developing care plans to consider the caregiver’s perspective to prevent or reduce caregiver burden. Generally, care needs are determined by a healthcare professional who then organizes formal care and equipment or refers to other specialist health services. Having a measure that caregivers can complete themselves, covering multiple aspects of care dependency could identify potential areas of unmet need, or be used serially, to identify a decline in a patient’s condition. Triangulation with the health professionals’ view on care dependency would add another dimension, providing an opportunity to ‘double-check’ that the patient and caregiver views are in alignment with the health professional. Another aspect raised but not directly examined by Durante et al.12 is the differences in the CDS and proxy CDS results. They found patients reported the highest care dependency with ‘mobility’ and ‘avoidance of danger’ while for caregivers, this was with ‘daily activities’ and ‘recreational activities’. A study by Kroenke et al.16 investigating agreement between proxy and self-report measures in older adults found closer agreement on physical compared with psychosocial domains and over reporting of dependency by caregivers when tasks were more difficult. Perhaps this explains why caregivers using the proxy CDS reported greater care dependency than patients for the more complex tasks of daily/recreational activities. Agreement on dependency assessment has been found to be lower with older age, poorer self-reported health, and low levels of prior activity.15 So more caution may be needed when interpreting proxy results from caregivers when the patient is more unwell or complex tasks are involved. Finally, it is important to consider the potential dual role of participants in Durante’s study being both proxy reporters and caregivers. Proxy measures are usually reported by a relative or friend who knows the patient well. However, many ‘proxy reporters’ will also be caregivers themselves potentially affected, often negatively, by the patient’s health situation. How does this effect the proxy reporting of the CDS? Are those caregivers in distress likely to report greater care dependency than the patient? This could mean they are a ‘poor’ proxy as the caregiver is not representing the patient’s view accurately. But discrepancy could also be an important warning sign of a situation at risk of breaking down and allowing early intervention and increased support. Further research is needed to test the utility of the CDS measure in clinical practice. However, by asking both patients and caregivers to complete it, the possibility arises of a measure that can identify not just unmet care needs but also discrepancies in the perspectives within the self-care dyad itself.