EFFECTS ON ILLNESS ON CAREGIVERS AND FAMILIES: A REVIEW OF SPILLOVER EFFECTS IN HEALTH

Purpose: To perform a systematic literature review on the spillover effects of illness on family members, relatives, and caregivers.

Method: The medical, psychology and economics literatures (PubMed, JSTOR and the Tufts Medical School Cost-Effectiveness Analysis Registry) were searched through 2010 for studies investigating spillover effects of illness on any aspect of life for family members and caregivers, including employed and informal caregivers, and parents, spouses, siblings and children of ill individuals.  Studies quantifying the spillover effect of illness using preference-based measures of health related quality of life published in any year were identified, in addition to review articles summarizing the effects of one individual’s illness on those surrounding him or her published during the last decade. 

Result: Eleven studies reporting preference-based estimates of the health related quality of life of caregivers for ill individuals were identified, with 9 of these estimating a negative spillover effect.  Most were focused on individuals who had explicit caregiving responsibilities for the ill individual, including parents, spouses, other family members, and less often, paid care givers.  Some explored or at least acknowledged the possible spillover effect of being in physical or emotional proximity to an ill individual, regardless of a caretaking  role.  We also identified more than 20 review papers reporting on the effect of illness on all aspects of surrounding individuals’ lives, with the majority (10) focusing on others’ quality of life, and of those, most investigating caregivers’ quality of life.  An additional 7 reviews reported on the spillover effect on others’ health, and a few (3) on other aspects of life, including finances. 

Conclusion: The effect of illness on surrounding individuals is measureable and affects domains ranging from quality of life to health to finances.  This effect has been studied across different types of relationships between ill individuals and their care takers, and across different types and severities of conditions.  Inclusion of spillover effects in economic evaluations of illness will create a more complete picture of the benefits gained across interventions.  Inclusion of these effects may improve measures of effectiveness for illnesses that have large spillover on others relative to those that have less spillover.  This phenomenon suggests consideration of a family or household utility function for use in economic analyses of health programs and interventions.