Table 3 Some proposals for future national health surveys.

Aspects to take into account		Recommendation
Sample		Bear in mind, when calculating sample size, the subsequent need to disaggregate the sample by the variables of interest. In order to study social inequalities in health both sex and socioeconomic level are necessary, and only with a sufficient sample size can in‐depth analyses of these relationships be tackled with the data disaggregated by these variables, and yet maintaining statistical significance.
Language used		Both the language of the interview and that of the instruction manual must take care that the terms used are not sexist or make one of the sexes invisible, and that there are no grammatical gender disagreements, nor stereotyped messages.
Variables to introduce or go into in more depth
Intimate partner violence		Strict confidentiality and safety must be ensured, and the topic only tackled when the interviewee is alone. Detailed questions aimed at illuminating gender differences in patterns, characteristics and risk factors for violence, as well as associated health problems should be included. Both men and women should be asked these questions in order to achieve the broadest possible approach to the problem.
Discrimination		Expand the questions introduced in ENS 2005–6, according to Stem Experience of Discrimination (EOD) Questionnaire.
Social support		Social support is a possible modulator of the impact on health of negative or stressful situations. It is important to introduce variables capable of capturing both emotional and instrumental support.
Immigration		Immigration is an issue that has taken on considerable importance in Spain over the past decade. It is important to study the health of the immigrant population including questions about country of origin, nationality and years living in Spain along with the standard variables.
Household structure/cohabitation		Household structure conditions: aspects such as non‐paid workload, overcrowding, form of cohabitation (single parent family, extended family, various family nuclei, etc).
Household work		Questions that allow determination of the family distribution of domestic tasks and caring for dependent members; availability of outside (contracted) help in carrying out domestic tasks; number of household work hours during work days and at the weekend.
Job characteristics		The questionnaire should include questions to permit characterisation of: occupation of the interviewee and if possible their partner or the person with the highest income in the household, type of job contract, economic activity and working schedule.
Social class and socioeconomic position		Based on occupation and educational level, the same questions ought to be asked to determine socioeconomic situation of the partner or other reference person in the household indicated by the interviewee (the person with highest income).
Mental health		It is necessary to include at least one instrument which permits an approach to the mental health of the population. We recommend Goldberg's questionnaire (GHQ12).
Morbidity		Questions which permit a differential analysis of morbidity by sex and gender. Morbidity symptoms within a period of two weeks before the date of the interview would be a helpful measure of self perceived health status.
Data analysis		(1) Compare findings of women and men, and supply context in the framework of social inequalities in health, for which it is not sufficient to simply fit models by sex (sex as a confounding variable), instead separate analyses should be conducted for each sex.
		(2) Consider relationships and interactions of sex with other contextual variables such as social class.
		(3) Study the diversity of groups of women and compare their health—for example, in terms of their domestic and paid work loads, presence of social support, or their having experienced situations of violence or discrimination.
		(4) The way results are expressed is also very important, since the aspects that are emphasised can condition the interpretation that is made.