Ward et al. BMC Public Health 2011, 11:431 http://www.biomedcentral.com/1471-2458/11/431 Page 4 of 9 Participants have the opportunity to select a card and be randomized upon arrival to a kick-off event. For each wave, three to four kick-off events are offered. At the beginning of each event, cards from each of 2 stacks are placed into either pail “A” or “B”, corresponding to income strata. The number of cards in the pail always exceeds the expected number of par- ticipants from each income stratum expected to attend the event. Cards in each pail are shuffled and as parti- cipants arrive, staff instruct participants to select one card from the appropriate pail. Cards remaining from the first event are left in the pails and used for the next event, with additional cards added as needed. Stratification procedures are not communicated to the participants. At these kick-off events, families randomized into the intervention group immediately start their first session, while those randomized into the control group have a short child entertainment program (e.g., book reading, puppet show). Participants must complete baseline mea- sures and attend one of these kick-off events in order to be randomized into the intervention or control group, and continue their participation in the study. This creates a run-in period and helps minimize loss to follow-up. Intervention The My Parenting SOS program was developed by a team of investigators with backgrounds in nutrition, physical activity, child obesity prevention, child and family psychology, and health communication (unpub- lished manual, My Parenting SOS Leader’s Guide); and builds off of multiple phases of pilot work which are summarized briefly in Table 1. Lessons gleaned from this work affirmed the need to target parents with pre- school-age children, and to integrate general parenting styles and specific food- and activity-related parenting practices. The program is delivered through 12 in-person group meetings and 11 tailored phone calls across 35 weeks. The group meetings include separate programs for par- ents and their children. Figure 2 Intervention model. Participants are recruited into the study and complete a baseline assessment before randomization. After either the 8-month My Parenting SOS intervention or child book club, participants complete a post-intervention assessment. The maintenance assessment are completed after a 6-month no- treatment period. between study arms across all strata. These randomiza- tion tables are then used to create sets of sequentially ordered cards that are sealed so that the condition assignment (control vs. intervention) appearing inside is not visible. Table 1 Formative and pilot work Date Activity June 2004 - Focus groups with mothers of overweight Jan 2005 children Focus groups with AA mothers Mar - May 2005 Sept - Oct 2006 Oct - Dec 2006 Objectives Identify culturally specific child management concerns and behavioral intervention needs of parents and/or caregivers, and their preferences for intervention channels and modalities [47] Explore barriers to healthy nutrition and activity practices at home, collect impressions regarding a parenting for healthy weight intervention, and assess preferences regarding intervention delivery Pilot of 4-part workshop series with parents Examine the acceptability of a parenting for healthy weight workshop series and from 1 local child care center evaluate appropriateness of potential measures Pilot of 3-part workshop series with parents Examine the feasibility of workshop delivery by trained facilitator (with a social work from 6 local child care centers background) provided at the child care center