The question was formulated following the recommendations of the 2nd Conference of the WHO (world health organization) in order to attain common methods and instruments for health questionnaires (Voorburg Conference 1990):

You consider that in general your health is: Very good / Good / Average / Bad / Very bad

As it is a very subjective answer and one which third parties are not allowed to answer, it was included in the individual questionnaire aimed at people aged 15 years and over.

It is one of the simplest health measures used and its relation with the use of services and mortality has been established in numerous studies (Mossey 1982, Idler 1990, Segovia 1989). Despite being a measure which is collected through only one item, it is valid as a general measure of health and it has been shown to be associated with illness and components of subjective health evaluation.