Study procedures
Consecutive children attending the standard 3.5-year psychosocial assessment of the DCHS were recruited by DCHS fieldworkers for the book-sharing intervention. After enrolment, block randomization to an intervention or control group which was completed off-site. Post-randomization confirmation was obtained that the gender of the children was evenly distributed among both groups. Outcome measures were collected at the 3.5-year psychosocial DCHS visit (baseline for the present study), and post-intervention 6 months later (4 years). Following the 3.5-year visit, the intervention group underwent the book-sharing intervention. The DCHS design allows only a few visits per year to reduce participant burden, the post-intervention assessments were scheduled for the 4-year psychosocial visit. During the pre- and post-intervention assessments, where needed, isiXhosa translators were used during assessments. Numerous breaks were given between tasks to ensure that the child did not get too tired, as assessments took approximately one hour to complete. Participants were reimbursed for travel expenses.