Background/Aims Care of children with mental health and developmental conditions (MHC) is often demanding and expensive, imposing both financial and time costs on families. Because costs to families are relatively difficult to quantify, most studies have focused on studying family costs using health system data which are more readily available. Few studies have collected cost data directly from families.

Methods This study presents results of psychometric analyses of a new instrument that directly measures family costs, the Family Economic Impact Interview (FEII). Reliability and validity of the FEII was evaluated as part of a developmental study which recruited a random sample of 70 parents of children with MHC between the ages of 3 and 12 years old from a large integrated health system. Parents were invited to participate in two interviews within a two week time period. Kappa statistics were calculated to evaluate the agreement between categorical variables.

Results We used standard cut off values (values over .75 - excellent agreement, values between .40 and .75 - good agreement, and values less than .40 - poor agreement). Reliability of parents’ reports of time spent in activities related to MHC were also good. In 20 of 24 time use categories, kappas ranged from .60 to 1.00. Validity of the FEII was assessed by examining the relationship between the degree of emotional burden a parent perceived from MHC and the amount of family costs measured by the FEII. We used regression analyses to examine whether there was a significant relationship between the main FEII outcomes and family emotional burden.

Discussion As hypothesized, we found significant positive association between emotional burden of care and family costs (p<.001). Preliminary analyses of the FEII indicate that a wide range of parents’ can complete the FEII, that parents’ can reliably report a variety of family costs including out-of-pocket financial costs and time costs, and that many families with children with MHC experience a wide range of costs – many of which have not been measured in previous studies.