Ethics approval and consent to participate
Specific approval was obtained for the Book-sharing RCT protocol (543/2017) from the Faculty of Health Sciences, Human Research Ethics Committee, University of Cape Town. Mothers provided informed consent at enrolment and yearly after that. Informed consent was obtained for all participants in their preferred language: English, Afrikaans, or isiXhosa, before the onset of the study. The DCHS was approved by the Faculty of Health Sciences, Human Research Ethics Committee, University of Cape Town (401/2009) and by the Western Cape Provincial Health Research committee. This study was conducted in accordance with the Declaration of Helsinki.