Subjective assessments of the quality of life are considered when measuring development. These measurements are built using population surveys where people are asked to define their situation on a qualitative scale. Information is obtained through simple surveys that capture subjective perceptions of access to certain goods. To formalize human ability to make decisions in uncertain environments, Zadeh (2011) defined Z-numbers, which provide a vague assessment and an idea of their reliability. Both can be expressed by linguistic variables. As perceptions of welfare dimensions and its indicators are heterogeneous and given that it is also interesting to value its impact, it is important to identify opinions and the frequency of those perceptions together. In this paper, it is presented a subjective valuation index of economic welfare with Z-information. To show how the model works, it is defined and calculated for one of the dimensions associated with household economic welfare: health system access. Identical procedure will be able to be extended to all the dimensions determined to measure wellbeing.