Cost of informal care for patients with cardiovascular disease or diabetes: current evidence and research challenges

Abstract

Purpose

Patients with cardiovascular disease (CVD) or diabetes often require informal care. The burden of informal care, however, was not fully integrated into economic evaluation. We conducted a literature review to summarize the current evidence on economic burden associated with informal care imposed by CVD or diabetes.

Methods

We searched EconLit, EMBASE, and PubMed for publications in English during the period of 1995–2015. Keywords for the search were informal care cost, costs of informal care, informal care, and economic burden. We excluded studies that (1) did not estimate monetary values, (2) examined methods or factors affecting informal care, or (3) did not address CVD or diabetes.

Results

Our search identified 141 potential abstracts, and 10 of the articles met our criteria. Although little research has been conducted, studies used different methods without much consensus, estimates suffered from recall bias, and study samples were small, the costs of informal care have been found high. In 2014 US dollars, estimated additional annual costs of informal care per patient ranged from $1563 to $7532 for stroke, $860 for heart failure, and $1162 to $5082 for diabetes. The total cost of informal care ranged from $5560 to $143,033 for stoke, $12,270 to $20,319 for heart failure, and $1192 to $1321 for diabetes.

Conclusions

The costs of informal care are substantial, and excluding them from economic evaluation would underestimate economic benefits of interventions for the prevention of CVD and diabetes.

Appendix 1: Adjustment of informal care hours and costs

We examined weekly informal care hours and annual informal care costs. When a study provided only monthly or annual informal care hours, we derived weekly informal care hours by dividing monthly informal care hours by 4.3 weeks/month or dividing annual informal care hours by 52 weeks/year. In the same way, when a study provided only weekly or monthly costs of informal care, we derived annual costs of informal care by multiplying weekly costs of informal care by 52 weeks/year or multiplying monthly costs of informal care by 12 months/year.

For comparison, we adjusted informal care cost into 2014 US dollars with the following equation:

$$\frac{{{\text{CPI in }}2014\,{\text{at a study country}} }}{\text{CPI in a study year at a study country}} \times \frac{{{\text{Informal caregiving costs}} \,{\text{from a study}}}}{{{\text{PPP exchange rate in }}2014 \left( {\text{local currency per US dollar}} \right)}}$$

Consumer price indices (CPI) of each study country were from the World Bank, and purchasing power parity (PPP) exchange rates were from the Organisation for Economic Co-operation and Development (OECD). For Thailand, which is not a member of OECD, we used the PPP conversion factor from the World Bank.