Objective: To determine the incidence of psychiatric morbidity (PM) in the area, and the associated demographic and socio-economic factors.
Design: Observational non-longitudinal study.
Setting: The population of a Basic Health Area.
Participants: Simple random sample of persons over 15 years old, selected from municipal census lists, accurate at 00.4. Initial sample: 697 cases. Excluded: deceased (11) changed address (112) serious mental incapacity (7) and refusal to take part (64). Final sample: 503 cases.
Measurements and main results: Answering of the General Health Questionnaire of 28 items (GHQ-28) and a questionnaire with study variables, between October 1990 and November 1991. 99 cases answered by post, and 404 via home visit. A GHQ-28 score greater or equal to 7 was considered positive. The incidence of GHQ-28 positive values in the population was found to be 0.35 (IC-0.31-0.39) and that of PM was found to be 0.38 (IC: 0.31-0.44). A link was observed with educational level (OR = 2.0277; p = 0.0174) and with sex (OR = 1.76 40; p = 0.172). There were no differences between those who answered by post or at home (p = 0.21) nor between those answering at different times of the year (p = 0.78).
Conclusions: There was a high incidence of PM in persons older than 15 in our health area. This incidence is associated in a significant way with level of education (higher amongst lower levels) and with sex (higher amongst women). These factors can be considered as risk markers which can help us to detect sufferers from this type of illness.