[Is stated income a valid indicator of the socioeconomic status?]

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.

Crossover and retrospective observation study.

Community (Molina de Segura Health District).

1,071 people over 18, selected by means of simple random sampling.

Analysis of 16 questions relating to home furnishing, consumer goods and stated income. We used Factorial Analysis and the ji2 test.

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.

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.