Contribution
All listed authors attest that they meet authorship criteria and that no others meeting the criteria have been omitted. The study design was conceived by all authors. O.J.R. and C.P.J. drafted the interview guide and the pamphlets, and T.P. and J.B. provided comments that led to revisions. All interviews were conducted and coded by O.J.R. and C.P.J. V.S. generated the allocation sequence and conducted statistical analyses. O.J.R. and C.P.J. drafted the manuscripts and T.P., J.B. and V.S. contributed to revisions. O.J.R. and C.P.J. are guarantors for this paper.