[Is stated income a valid indicator of the socioeconomic status?]. / Son válidos los ingresos declarados como indicador del nivel socioeconómico de la población?

ABSTRACT

OBJECTIVE: 1) To analyse the validity of the reply to the question on socio-economic income included in health questionnaires. 2) To identify other valid indicators of socio-economic status. DESIGN: Crossover and retrospective observation study. SETTING: Community (Molina de Segura Health District). PARTICIPANTS: 1,071 people over 18, selected by means of simple random sampling. INTERVENTIONS: Analysis of 16 questions relating to home furnishing, consumer goods and stated income. We used Factorial Analysis and the ji2 test. RESULTS: We identified three levels by means of the factorial analysis: a) basic--consisting of hot water, washing-machine, absence of damp patches in the house, individual heating and television. b) Intermediate--consisting of car, video and telephone. c) High--with dishwasher, domestic help and air-conditioning. On analysing the relationship between stated income and socio-economic status we detected association to p < 0.001. The basic level answered more often than expected that their income was less than 50,000 pesetas; the intermediate, between 50 and 100,000; and the high, over 101,000. CONCLUSIONS: 1) It is possible to identify the socio-economic profile of the general population by the belonging of selected of determined consumer items. 2) Stated income is a reliable indicator of socio-economic status. Despite a tendency to a low reply to the question on income, income is not generally under-declared.