[Methodological Aspects of the Sampling Design for the 2015 National Mental Health Survey]

The WHO has encouraged the development, implementation and evaluation of policies related to mental health all over the world. In Colombia, within this framework and promoted by the Ministry of Health and Social Protection, as well as being supported by Colciencias, the fourth National Mental Health Survey (NMHST) was conducted using a observational cross sectional study. According to the context and following the guidelines and sampling design, a summary of the methodology used for this sampling process is presented. The fourth NMHST used the Homes Master Sample for Studies in Health from the National System of Studies and Population Surveys for Health to calculate its sample. This Master Sample was developed and implemented in the year 2013 by the Ministry of Social Protection.

This study included non-institutionalised civilian population divided into four age groups: children 7-11 years, adolescent 12-17 years, 18-44 years and 44 years old or older. The sample size calculation was based on the reported prevalences in other studies for the outcomes of mental disorders, depression, suicide, associated morbidity, and alcohol use. A probabilistic, cluster, stratified and multistage selection process was used. Expansions factors to the total population were calculated.

A total of 15,351 completed surveys were collected and were distributed according to the age groups: 2727, 7-11 years, 1754, 12-17 years, 5889, 18-44 years, and 4981, ≥45 years. All the surveys were distributed in five regions: Atlantic, Oriental, Bogotá, Central and Pacific.

A sufficient number of surveys were collected in this study to obtain a more precise approximation of the mental problems and disorders at the regional and national level.