The potential confounding variables were sequentially introduced in the models: initially, sex, age, and ethnicity; subsequently, those that were related with the socioeconomic position, such as degree of schooling and family income per capita; finally, we included the body mass index BMI and the presence of comorbidities.
Introdujimos en los modelos, secuencialmente, las potenciales variables de confusión: inicialmente, sexo, edad y color/raza; posteriormente las que se relacionan con la posición socioeconómica, como escolaridad y renta domiciliaria per capita; por fin, incluimos el índice de masa corporal IMC y la presencia de comorbilidades.