A single question about a respondent's perceived financial ability to pay monthly bills explains more variance in health utility scores than absolute income and assets questions.

PURPOSE: To evaluate a general question about ability to meet monthly bills as an alternative to direct questions about income and assets in health utility studies.
METHODS: We used data from the National Health Measurement Study-a US nationally representative telephone survey collected in 2005-2006. It included health utility measures (EuroQol-5D-3L, Health Utilities Index Mark 3, Short Form-6D, and Quality of Well-being Index) and household income, assets, and financial ability to meet monthly bills questions. Each utility score was regressed on: income and assets (Model 1); difficulty paying bills (DPB) (Model 2); income, assets, and DPB (Model 3). All models used survey weights and adjusted for demographics and education.
RESULTS: Among 3666 respondents, as income and assets increased, DPB decreased. The DPB question had fewer missing values (n = 30) than income (n = 311) or assets (n = 373). Model 2 (DPB only) explained more variance in health utility than Model 1 (income and assets only). Including all measures (Model 3) had very modest improvement in R (2), e.g., values were 0.112 (Model 1), 0.166 (Model 2), and 0.175 (Model 3) for EuroQol-5D-3L.
CONCLUSIONS: The single question on DPB yields more information and has less missing values than the traditionally used income and assets questions.