Warschburger and Kröller BMC Public Health 2012, 12:295 http://www.biomedcentral.com/1471-2458/12/295 Differences regarding the recruitment strategies were con- trolled accordingly. Statistical analyses All analyses were performed using SPSS 20.0 (Chicago: SPSS inc.). Because missing data rates were below 5% and missing analyses did not show any associations between missing values and included variables, Expectation Maximization substitution was applied for metric scales. Based on the marked silhouettes, the identification of overweight and the associated health risk, as well as the perceived need for preventive action were grouped as fol- lows: at the 75th percentile or before, at the 90th percentile and at the 97th percentile. We submitted the data on demographic and weight differences regarding the recruit- ment strategies as well as the maternal ability to identify overweight silhouettes and their perception of the need for preventive activities to ANOVAs and χ2 tests where appropriate. To analyze factors associated with maternal desire to engage in child weight management at different weight points, we used a multinomial logistic regression analysis. Using the 90th percentile as a reference point, we contrast an early-action need (operationalized as the 75th BMI percentile or lower) and an already-too-late action need (operationalized as the 97th BMI percentile) as repre- sented by the silhouettes. Based on previous research, demographic and weight aspects (child’s sex and age, weight status of mother and child, maternal education and income level), maternal dissatisfaction with the child’s sil- houettes (satisfied/preferred heavier silhouettes/preferred thinner silhouettes) as well as their ability to identify over- weight silhouettes (75th percentile/90th percentile/97th per- centile) and the related health risks (75th percentile or before/90th or 97th percentile) were included in the predic- tion model. Results Identification of overweight silhouettes and related health risks Overall, 150 mothers (43%) identified the overweight sil- houettes (90th and 97th percentile) correctly, and 56 mothers (16%) identified only the 97th percentile as over- weight (see Table 2). Demographic and weight related influences produced no significant differences in the mater- nal ability to identify overweight silhouettes (χ2 (df = 1) 0.01 Identification of overweight Identification of mental health risk Identification of physical health risk Perceived need for action Page 4 of 8 – 3.25; p = .92 - .07). Only 50% of mothers believed that sil- houettes above the 90th percentile carry a higher physical risk, and only 46% believed that these silhouettes were related with higher mental health risk. Mothers who were able to identify these health risks correctly were more often higher educated (χ2physical (df = 1) 4.40, p = .04; χ2mental (df = 1) 5.00, p = .03) or had overweight children (χ2physical (df = 1) 4.54, p = .03; χ2mental (df = 1) 3.75, p = .05). Dissatisfaction with the child’s silhouette Regarding the discrepancy between the ideal and the ac- tual body size, most parents were content with the current figure of their child (62%). Of those who were not, the majority preferred a slightly heavier (24%) than a thinner (14%) silhouette for their child. This maternal dissatisfaction with the child’s body size differs depend- ing on the child’s age and weight as well as the mother’s weight. Mothers of older children more often preferred a thinner silhouette for their child than mothers of younger children (χ2 (df = 2) 11.64; p < .01). Additionally, mothers who had an overweight child (χ2 (df = 2) 137.16; p < .01) or were overweight themselves (χ2 (df = 2) 23.07; p < .01) pre- ferred thinner silhouettes. The perception of the need for action to prevent overweight In general, mothers pointed out different silhouettes as the right indications of prevention efforts. 51% of the mothers indicated the silhouette of the 90th percentile as a starting point for engaging in child weight manage- ment. 19% indicated no need for action until the 97th percentile, and 30% indicated silhouettes in the 75th or 50th percentile as needing professional help (see Table 2). The maternal perception of the need for preventive actions differs only with respect to child’s age: mothers of younger children indicated the need for weight man- agement strategies for heavier silhouettes than mothers of older children (χ2 (df = 2) 18.95; p < .01). Prediction model To predict the maternal recognition of the need for pre- ventive actions in silhouettes of children in the 75th to 97th percentiles, we used a multinomial logistic regression in- cluding demographic variables (sex, weight, educational level and income), maternal perception of overweight, Table 2 Identification of overweight silhouettes, the related health risk and perceived need for action n = 14 (4%) 50. 0 0 n = 16 (4%) 75. n = 137 (38%) n = 31 (14%) n = 43 (20%) n = 92 (26%) Percentile: 90. n = 153 (42%) n = 111 (50%) n = 111 (50%) n = 179 (51%) 97. n = 56 (16%) n = 80 (36%) n = 65 (30%) n = 65 (19%)