Ward et al. BMC Public Health 2011, 11:431 http://www.biomedcentral.com/1471-2458/11/431 Control Condition Families randomized into the control group are enrolled into a child’s book club. The child entertainment pro- gram offered at kick-off events is intended to help launch the book club program and is generally con- ducted by local librarians. Families receive one book each month, mailed directly to their home, for the dura- tion of the 35-week intervention period. Book titles for this arm were identified with the assistance of a child’s librarian. Books related to health, nutrition, and physical activity were purposefully avoided when selecting titles. Mailing of books directly to participants’ homes also helps monitor for changes of address among control families. Outcomes and Measures Outcomes are assessed at three time points: baseline, post-intervention, and maintenance (6-month post). Measurement events are scheduled at convenient com- munity locations so that participating families can come in and complete measurements. Locations allow for multiple stations including check-in, anthropometric measures, parent psychosocial surveys, accelerometry, and check-out. Locations also provide space for child activities to keep children entertained while parents complete surveys. Primary Outcome The primary outcome is mean change difference in child percent body fat between baseline and post-intervention. Percent body fat is calculated using the formula of Dezenberg et al.[17] which incorporates weight, triceps skinfold, gender, and race/ethnicity. Collection of anthropometric data is described in detail below; sex is captured by the technician during measurement; and race/ethnicity is reported by the parent. The Dezenberg equation has been validated in 4-11 yr old Caucasian and African American children and found to be highly predictive of body fat mass measured by DEXA (R2 = 0.95, Model SEE = 0.50)[17]. Secondary Outcomes Anthropometry Standing height and weight are mea- sured by a trained technician on both children and par- ents. Height is measured to the nearest 1/8 inch with a Shorr or Seca infant/child/adult measuring board (Shorr Productions, Olney, MD; Seca Corporation, Columbia, MD); and weight is measured to the nearest 0.1 lb with a Seca model 770 portable electronic scale (Seca Cor- poration, Columbia, MD). Additional anthropometric measures taken on children are triceps and subscapular skinfold thickness and waist circumference. Skinfold thicknesses are measured to the nearest 1.0 mm using Lange calipers (Beta Technology, Inc. Cambridge, MD); and waist circumference is measured to the nearest 0.1 cm using a Gulick II measuring tape. These measures Page 6 of 9 are also used to calculate child and parent BMI, child BMI z-score, and child sum of two skinfolds. Diet Parent and child diet are assessed using three days (2 weekdays and 1 weekend day) of unannounced 24- hour dietary recalls collected over a 4-week period. All recalls are conducted under the direction of the UNC Nutrition Epidemiology Core (CNRU, NIH DK056350) using traditional multi-pass procedures which provide cues for portion size, use of condiments, etc. [18-20]. All recalls are conducted with parents who are asked to recall what they ate the previous day and what their child ate while in their care. The NDS-derived analyses conducted on three 24-hr dietary recalls allows for ana- lysis of intakes of energy, saturated fat, servings of fruits, vegetables, and whole grains, and intake of sugar-swee- tened beverages. Physical Activity Parent and child physical activity are assessed with ActiGraph GT3X accelerometers (Acti- Graph, LLC, Fort Walton Beach, FL). Parent monitors are programmed to collect data in 1-min epochs, while child monitors use a 15-sec epoch to capture their vari- able movement patterns. Monitors are worn over the right hip, for seven consecutive days, during waking hours, except when in water. Data are reduced using the adapted SAS code used in NHANES, and appropriate cut-points are applied to determine time spent in seden- tary, light, moderate, and vigorous physical activity. We will use the current NHANES accelerometer cut-points used for parent data [21], while cut-points recently developed by Evenson et al. for 3-5 yr old children are used for child data [22]. The ActiGraph has been found to be effective for measuring both physical activity and inactivity in preschool-age children [23-25]. General Parenting Practices Existing scales are also employed to measure parent practices addressed as part of the intervention, including: (1) the Alabama Parenting Questionnaire - Preschool Revision (APQ-PR), which includes subscales for positive parenting, inconsistent parenting, and punitive parenting [26]; (2) the Difficul- ties in Emotion Regulation Scale (DERS), which assesses parent ability to manage their own emotional responses and includes subscales for non-acceptance of emotional responses, difficulties engaging in goal-directed behavior, impulse control difficulties, lack of emotional awareness, limited access to emotion regulation strategies, and lack of emotional clarity [27]; (3) the Coping with Children’s Negative Emotions Scale (CCNES), which assesses how parents react to children’s negative affect in distressful situations and includes subscales for distress reactions, punitive reactions, expressive encouragement, emotion- focused reactions, problem-focused reactions, and mini- mization reactions [28,29]; (4) the Confusion, Hubbub, and Order Scale (CHAOS), which assesses parental time management skills (e.g., use of routines) [30]; and (5)