1Ministry Of Health, Chile, Santiago, Chile, 2Department of Family Medicine and Public Health, University of California at San Diego, California, # 9500 Gilman Drive, La Jolla, CA 92093, San Diego, USA, 3School of Public Health, Pontifical Catholic University of Chile, Av. Libertador Bernardo O’Higgins 340, Santiago, Santiago, Chile, 4Department of Nutrition, Faculty of Medicine, University of Chile, Av. Independencia 1027, Independencia, Santiago, Chile, 5School of Public Health, University of Chile, Av. Independencia 939, Independencia, Santiago, Chile, 6Institute of Nutrition and Food Technology, University of Chile. Av. El Libano 5524, Macul, Santiago, Chile.
Background: Chile implemented two policies aiming to support exclusive breastfeeding (EBF): twelve extra weeks of maternity leave (ML), in 2011; and pay for performance (P4P) primary health care strategy for EBF promotion at six months, in 2015. On the other hand, evidence shows that COVID-19 might have affected EBF prevalence. This study aims to examine the impact of these two policies and COVID-19 in EBF prevalence, at three and six months, by national level, urban and rural settings, geographical zones and EBF inequalities by socio-economic status (SES). Methods: Aggregated national EBF data by month and municipality were collected from January 2009 to November 2020. Interrupted time series analyses (ITSA) were performed to quantify the changes in EBF attributable to the two policies and COVID-19. Stratified analyses were made by urban and rural setting, geographical zones. The impact of the three events in EBF inequalities was measured with two procedures: 1. ITSA stratified by municipal SES quintiles; 2. Calculating the EBF slope index of inequality (SII).Results: EBF prevalence at six months increased from 49.2% to 51.5% after the extended ML, from 50.5% to 63.1% after the P4P, and from 62.9% to 64.8% after COVID-19. The EBF prevalence was higher in lower SES municipalities before and after the three time-events. We found no effect of ML on EBF; the P4P increased EBF at three months by 3.1% and 5.7% at six months. COVID-19 reduced EBF at three months in -4.5%. Heterogeneity by urban and rural settings and by geographic zones were identified in the impact of the two policies and COVID-19 in EBF. No impact in EBF inequalities were observed after the extended ML. The P4P increased EBF at six months in all SES quintiles, but in a higher level in poorer municipalities (SII: -0.36% and -1.05%). During COVID-19, wealthier municipalities showed a higher EBF prevalence at six months (SII: 1.44%). Discussion: The null effect of ML on EBF could be explained by a low access among affiliated to the public health system to ML (20%) and by an insufficient ML duration (five and a half months). The negative impact of COVID-19 on EBF should alert on the effect that crisis might have on health promotion activities. The P4P strategy includes multiple interventions that seemed effective in increasing EBF across the country, but further in lower SES quintiles. The restrictions in healthcare access in poorer municipalities could explain EBF inequalities during COVID-19.
Keywords: health policies, COVID-19, exclusive breastfeeding, socioeconomic status, time series.