Notas metodológicas para aumentar la adherencia a un estudio sobre lactancia materna en un colectivo de mujeres de Bilbao: Estudio Zorrotzaurre.

Resumen

Background: Breastfeeding (BF) is the natural way of feeding infants and young children and has been shown to have multiple health benefits for mothers and infants. This article aims to describe the methodology used in a study to estimate the prevalence of BF during the first year of life in children of women who give birth in a private clinic in Bizkaia and to identify factors related to BF. Methods: Observational, descriptive, longitudinal and prospective study in a selected random sample from September 2016 to August 2017. After recruitment, a 1-year follow-up was carried out. Data collection was performed from the medical history through five interviews (face-to-face and telephone). Sociodemographic, biosanitary, obstetric, perinatal data, type of diet and related factors were collected. Results: The methodology used allowed obtaining the necessary estimated sample size, with a low percentage of women who refused to participate and a high percentage of adherence. Of the 453 women initially contacted, 87 did not wish to participate in the full study, of these 23 were excluded for opting for artificial feeding, 60 agreed to conduct a survey at 6 months and 4 indicated the type of diet, but refused to be contacted. Of the other 366 women who participated, 42 cases were lost (11.47%). Conclusions: The follow-up strategy allowed high participation. The approach to women who refused to participate in all phases of the study may be of interest to visualize the bias that nonparticipants could suppose.