Some of the more innovative methods the study co- zzdinators utilized to encourage retention of the child in the rial included allowing for flexibility in scheduling return study visits——within protocol guidelines——around the parti- cipant’s and their family’s school and work commitments. Study coordinators used close telephone call follow-up with families to ensure their understanding of what was expected with regards to return visits and compliance with study a prnedication administration and dosage. Close contact was especially helpful when subjects needed to change their dose, missed doses, or took medication later than expected; subjects could call the coordinator at any time and obtain advice. Several of the investigator/coordinator teams attempted to be available around the clock. If an investigator was not going to be available by telephone or pager, the site ‘coordinator was able to contact any investigator in the PEDS-C group for emergency consultation.