Quantifying Family Spillover Effects in Economic Evaluations: Measurement and Valuation of Informal Care Time

Abstract

Spillover effects on the welfare of family members may refer to caregiver health effects, informal care time costs, or both. This review focuses on methods that have been used to measure and value informal care time and makes suggestions for their appropriate use in cost-of-illness and cost-effectiveness analyses. It highlights the importance of methods to value informal care time that are independent of caregiver health effects in order to minimize double counting of spillover effects. Although the concept of including caregiver time costs in economic evaluations is not new, relatively few societal perspective cost-effectiveness analyses have included informal care, with the exception of dementia. This is due in part to challenges in measuring and valuing time costs. Analysts can collect information on time spent in informal care or can assess its impact in displacing other time use, notably time in paid employment. A key challenge is to ensure appropriate comparison groups that do not require informal care to be able to correctly estimate attributable informal care time or foregone market work. To value informal care time, analysts can use estimates of hourly earnings in either opportunity cost or replacement cost approaches. Researchers have used widely varying estimates of hourly earnings. Alternatively, stated-preference methods (i.e. contingent valuation, conjoint analysis) can be used to value the effect of informal care on utility, but this can entail double counting with health effects. Lack of consensus and standardization of methods makes it difficult to compare estimates of informal care costs. Electronic supplementary material The online version of this article (10.1007/s40273-019-00782-9) contains supplementary material, which is available to authorized users.

Advances in Methods and Novel Applications for Measuring Family Spillover Effects of Illness

“…Methods for measuring and valuing informal caregiving time are widely heterogeneous in the literature and five papers in this special issue address this topic. Grosse et al provide a thorough and comprehensive review of alternative methodologies and highlight how the selection of methods can impact results and impede comparisons across analyses [7]. This overview is complemented by three examples of specific methods for valuing time: willingness to pay of a caregiver intervention [8], a discrete choice experiment to value informal care for children with intellectual disability using a willingness-to-pay approach [9], and a discrete choice experiment to value an hour of informal care using a willingness-to-accept approach [10].…”

“…This issue provides several tools for analysts-methods for valuing informal care [7], a comprehensive catalog of caregiver utilities [14], and an algorithm for generating caregiver time using patient-level EQ-5D data [11]. Much guidance is still needed especially in best practices for valuing informal care time and measuring spillover burden via health utilities.…”

Spillover Effects on Caregivers’ and Family Members’ Utility: A Systematic Review of the Literature

“…It is broader and more comprehensive than a previous review that focused on spillover utility only; this review includes caregiver and family member utilities from which spillover can be estimated or derived, and preference-based measures of caregiving effects beyond health [13]. Spillover costs for informal care are also recommended for inclusion, and have been reviewed and discussed elsewhere [17,18]. Along with this catalog and the opportunity to incorporate spillover effects into CEAs come a host of questions, all of which have practical and policy implications: what is and is not considered spillover by different investigators; how can and cannot spillover be captured using different measures and populations; and how and under what circumstances it should or should not be included in CEAs.…”

“…While out-of-pocket expenses and time spent caregiving are relatively simple to quantify, assigning value to time is more daunting. Multiple valuation approaches have been proposed without clear guidance for a preferred method [17,18]. Including informal time costs in CEA is becoming more common, although it is still the exception [17,19].…”

“…Including informal time costs in CEA is becoming more common, although it is still the exception [17,19]. This review focuses exclusively on QALY-related spillover effects, and readers are referred elsewhere for considerations of cost spillovers [17,18].…”