Breastfeeding: what changed after a decade?1.

The 2013 study sampled children enrolled in primary health care facilities who attended with their mothers, while the 2001 study was population-based, so the two samples were not the same kind of group. The analysis compared 302 children under two years of age in 2013 with 261 children under two years of age in 2001, so children aged two to three years in the 2013 sample were not included in this comparison. Several breastfeeding promotion actions were measured only in 2013, not in 2001, so the study could not compare how those actions changed over the decade. The study measured whether breastfeeding support actions occurred, not their quality or how they were delivered, so it cannot tell whether the content of the actions was adequate. Because this was an observational comparison of two cross-sectional surveys, it cannot show that public policies, counselling, pacifier reduction, or any other factor caused the changes in breastfeeding. Breastfeeding status and exposure information came from interviews with mothers, so the estimates depend on maternal report at the time of the interview.

The work was supported by Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP), Brazil. The supplied text reports no competing interests.

Do not read the rise in breastfeeding as proof that the recorded promotion actions worked. In the adjusted analysis, those actions were not statistically associated with weaning, and the study compared two different cross-sectional samples, so it cannot show cause.