Background
Chronic and co-morbid conditions commonly experienced by older people are often related to disability [
1] meaning that needs for caregiving support can often be anticipated. Substantial caregiving input is often provided at home from family and friends (hereafter called ‘family caregivers’) and is becoming a common scenario associated with population ageing [
2]. The value of family caregivers to the community is enormous in terms of monetary as well as social benefits, as documented in a recent Australian report [
3]. Although the use of different methodologies to determine savings to the community from caregiver input means that comparisons need to be made with caution, estimates are that caregiver contributions to economies range from 0.3% of Gross Domestic Product (GDP) in France to 7.4% of GDP in the UK. Australian caregivers contributed 3.8% to the GDP in 2015, with an estimated monetary value of more than $AUD60 billion [
3]. Although caregiving impacts vary substantially depending upon the unique context of the caregiving situation, poor caregiver health is frequently documented and has the potential to limit the sustainability of home care [
4].
Unplanned hospitalisation occurs for older people in poor health for a variety of reasons including progression of existing illness, acute (new) health problems and problems with accessing appropriate care or support in the home [
5]. A previous investigation by members of our team determined that caregivers of older patients discharged home from one acute medical assessment unit (MAU) felt underprepared to provide appropriate care after the discharge [
6]. Although hospitalisation of the person receiving care can be experienced as a challenge to the caregiver [
7], it also provides an opportunity for the hospital staff to determine and address needs for caregiving support [
8]. If utilised in this way, the health of the caregiver may be maintained, unnecessary returns to hospital may be averted, and the long term sustainability of the home care situation enhanced.
We have previously published findings of a trial to determine the outcomes for family caregivers of older people from being included in an intervention – the Further Enabling Care at Home (FECH) program – upon discharge from hospital of the older person for whom they were providing care at home [
8]. The FECH program is a telephone-administered intervention in which a specially trained nurse determines the caregiver’s understanding of the patient’s discharge letter, advising how to obtain further clarification if required, and facilitates the caregiver’s determination and prioritisation of their caregiving and support needs, providing guidance regarding access to support. This study found that caregivers included in the program experienced improved preparedness to care as well as reduced caregiver strain and reduced caregiver distress. Similar telephone-based programs have reported positive outcomes for caregivers of patients with various needs including stroke [
9] and dementia [
10]. Despite these findings, such interventions may be impractical or unappealing to policy-makers if the costs required to implement them are prohibitively high.
Given the continued increases in health-care expenditure in developed countries [
11], cost-effectiveness analyses of interventions are increasingly important. Cost-effectiveness analysis can aid decision-makers in determining which interventions are worth funding by providing a better understanding of the investment required to achieve a certain outcome and therefore weighing the opportunity costs of funding one intervention as opposed to another [
12]. Similarly, evidence on how an intervention may impact on the use of health services is useful to planners in deciding where funding should be allocated. That is, an intervention which results in reduced use of health services elsewhere in the system may be appealing as intervention costs may be partly or fully recovered through this reduction in use. To our knowledge, there are no published studies of telephone-based interventions to support caregivers of older patients which report on intervention costs, cost-effectiveness or on the potential health system impacts of interventions.
The aims of the current paper are therefore to (1) examine whether positive outcomes for caregivers resulting from FECH led to changes in the use and costs of hospital and ambulance services by patients; and (2) assess the cost-effectiveness of the intervention. We hypothesised that FECH would improve caregiver preparedness and that this would result in reduced use of health services by patients, partially offsetting the costs of delivering the intervention.
Discussion
In this study we aimed to examine whether positive outcomes for carers resulting from FECH led to changes in the use and costs of hospital and ambulance services by patients, and to assess the cost-effectiveness of the intervention. We hypothesised that the intervention would reduce the use of health services by patients, partially offsetting the intervention costs. The FECH intervention was found to lead to improvements in preparedness to care, at a cost of $AUD1,731 for each additional caregiver reporting an improvement in preparedness to care at Time 2. There was a cost of $AUD1,789 for each additional one-point improvement in caregiver distress and $AUD1,677 for each additional one point improvement in caregiver strain. Improvements on each of these outcomes were statistically significant, as reported previously [
8]. It is important to note that there is overlap between these outcomes, as each dollar invested contributes to multiple caregiver benefits. The outcomes for caregivers did not, however, translate to changes in patient use of hospital services in the three months following recruitment.
In interpreting cost-effectiveness figures it is important to consider the potential “willingness to pay” for the outcome in question [
12]. In this case willingness to pay would refer to the amount the funder (i.e. the West Australian Department of Health, reflecting the perspective of the analysis) would be willing to pay for each additional caregiver reporting an improvement in preparedness to care. There is currently no guidance available as to what the funder, or anyone else, may be willing to pay for this outcome. Furthermore, we are unaware of interventions of any type which have used the preparedness for caregiving scale and reported on cost-effectiveness against which we could compare these findings.
There is a small number of published cost-effectiveness studies comparable to the FECH trial in terms of intervention aims, which focus on caregivers of people with dementia. One study, conducted in the Netherlands, trialled an intervention in which caregivers of people with dementia attended a series of sessions including counselling and family meetings individualized to meet the caregiver’s needs which aimed to offer psycho-education, teach problem-solving techniques and mobilise family networks to provide support [
31]. A similar study conducted in the UK assessed an intervention of eight face to face therapy sessions delivered by specially trained health professionals for caregivers of people with dementia, with a focus on caregiver coping [
32]. While the UK study reported an ICER of £189 for each carer reporting an improvement in anxiety/depressive symptoms in excess of the MCID on the scale used, the Netherlands study reported an ICER of €9271 for each incidence of major caregiver depression/anxiety avoided. The current study produced ICERs for caregiver preparedness to care, caregiver strain and caregiver distress which fell between the ICERs reported for improvements in depression/anxiety in these studies, though the different populations assessed, different health systems in which the studies were conducted and different outcomes assessed may limit comparability.
It is likely that the effectiveness and cost-effectiveness of the FECH intervention would differ across populations. Previous research into family caregivers of palliative patients found that caregivers who were less vulnerable at baseline did not benefit from a psychoeducational intervention aimed at improving preparedness for caregiving [
33]. Although the intervention and patient population differed from the current study, similar issues could impact on the observed effectiveness of FECH, considering that the participating family caregivers tended to be well educated and may have had relatively few support needs [
8]. A targeting of the intervention at those caregivers with greater needs may result in increased effectiveness. Of course, this may also result in higher intervention costs if additional nurse time is required in supporting such caregivers.
In this trial cost-effectiveness was improved in the per-protocol analysis compared to the LOCF “base case”. It is possible that outside of a trial setting where caregivers would not be expected to complete lengthy assessment tools in addition to the time involved participating in the intervention, follow-up and hence effectiveness may improve. Regardless, the difference in cost-effectiveness between the LOCF and per-protocol analyses suggests that targeting the intervention towards caregivers least likely to withdraw may be an essential part of making this intervention as cost-effective as possible.
We found that patient use of hospital, ED and ambulance services did not differ between groups. This may well reflect that preparedness to care, caregiver distress and caregiver strain do not impact on the health of patients, or at least on their need for hospital and ambulance services, within the brief follow-up period considered during this study. Even if caregiver preparedness does impact on need for these services, it is just one of many factors influencing hospital use. Variation introduced by other factors (e.g. patient condition, distance to services, socioeconomic status) would have the effect of making any between-group differences resulting from changes in caregiver preparedness more difficult to identify, given this study was powered for the preparedness to care outcome. Additionally we did not examine the use of primary care, community health, hospital outpatient or other services which may also be accessed by patients and caregivers facing difficulty. Given the high acute care costs across both groups within the three month follow-up, even a modest reduction as a result of FECH could make a substantial difference to cost-effectiveness. Further research, powered for health service use outcomes, would provide a vastly improved estimate of cost-effectiveness.
The intervention was found not to impact on caregiver self-rated physical or mental health to either follow-up. It is counterintuitive that the intervention’s effects on preparedness to care, caregiver strain and caregiver distress were not reflected in changes in self-rated health. It may be the case that the study, being powered to detect changes in preparedness to care, was underpowered to detect changes in self-rated health where there are likely to be many additional sources of variation present. It is also intuitive that changes in caregiver strain, caregiver distress and other outcomes may take time to filter through to caregiver health, while this study had a relatively short follow-up. In a similar CSNAT trial in community palliative care, while the intervention was associated with a significant reduction in the FACQ-PC caregiver strain, the differences in SF12v2 scores were not significant [
34]. The authors postulated that this result may be due to SF12v2 not accurately capturing the outcome for the study within the short time period of the intervention, or that the intervention had limited effect in this case.
The FECH nurse recorded detailed notes on the time spent working with each caregiver during the trial, and as such we can be confident in the accuracy and completeness of intervention costs recorded here. It is worth noting here that undertaking such interventions in a research setting rather than a routine practice setting is more time consuming and more burdensome on service providers, as already reported in a similar trial [
34,
35]. Therefore total costs would be reduced if and when this intervention is integrated in standard practice. Administrative data were accessed to ascertain the use of hospital, ED and ambulance services by each patient, hence these comparisons are not impacted by recall bias. Groups were well balanced at baseline on all demographic and outcome measures assessed. Although loss to follow-up differed between groups, we were able to perform cost effectiveness analysis dealing with missing data through two different methods to understand the possible impact of this on findings.
The analyses reported here have several important limitations. Firstly, the perspective of the analysis may impact on generalisability. This study focussed on hospital costs because these costs are major cost drivers [
36] and are compounded by the adverse events experienced by older people in the hospital setting [
37], meaning that there is a significant imperative to minimise hospitalisation for older people to minimise both costs and suffering. We were also unable to consider any impacts on patient or caregiver out-of-pocket costs. The trial had a relatively short follow-up, and it is possible that changes in some outcomes may take longer to manifest. The health conditions experienced by older people in many cases are not curable and are characterised by a gradual deterioration or repeated exacerbations [
38]. As such, an intervention aimed at improving preparedness to care would ideally have a lasting effect. A future study with a longer follow-up would provide better indications of the extent to which supporting carers can help to maintain an older person at home following discharge.
Additionally, the trial was powered to detect changes in the primary outcome of caregiver preparedness, and may have been underpowered to detect changes in health service use, which may substantially impact on cost-effectiveness. Finally, some participants failed to complete all time points so missing data may impact on results here. We reported results using the conservative LOCF approach, and repeated key analysis using only data from completers (“per-protocol”) as a sensitivity analysis to better understand the impact of missing data. The choice of method did not impact on the significance of changes in preparedness at either follow-up, though the positive effect of the intervention on preparedness to care at Time 2 was greater under the per-protocol analysis. The LOCF therefore may have provided conservative estimates of cost-effectiveness.