OBJECTIVES : To realize the first estimate of the cost of informal care associated with epilepsy, Parkinson disease (PD), and multiple sclerosis (MS) with the contingent valuation method (CVM).

METHODS : Individuals with MS (n=58), PD (n=96), or epilepsy (n=193) declaring informal caregivers in the French Health and disabilities households survey (Enquête Handicap-Santé) were classified in non-dependent, moderate and severe levels of dependency for the activities in daily living. The mean cost of informal care from the main caregiver per year was calculated with the Proxy Good (PGM), Opportunity Cost (OCM), and CVM methods.

RESULTS : The monthly mean (standard deviation, SD) number of informal care hours per care recipients was 142 (201) in PD, 138 (170) in MS, and 151 (180) in epilepsy. It increased with the level of dependency. The PGM and OCM produced similar costs (mean difference [SD] of €243 [440]). The CVM produced greater costs in severely dependent forms- (mean cost [SD] of €187,029 [328,058] versus €25,685 [22,520] for both OCM and PGM in MS; and €41,915 [38,157] with CVM versus €34,627 [25,263] with OCM, and €34,545 [25,308] with PGM in epilepsy).

CONCLUSIONS : By revealing the preferences of informal caregivers, the CVM could catch intangible effects of informal care related to severe MS and epilepsy, compared to PGM and OCM which consider only the effect on caregivers’ productivity in the labour market. However, numerous methodological questions remain about the calculation of the informal care cost and its implementation in economic evaluations.