Research
All analyses were conducted using IBM SPSS Statistics version 23. Outliers for the pedometer data were identified as days with <1,000 or >30,000 steps/day for children and <1,000 or >25,000 for adults were set as missing . Outliers for the child PA questionnaire (>6 h/day), and for the other continuous variables (? ± 3.29 SD) were truncated .
Pearson equipment–second correlations had been cost sample the unadjusted bivariate relationship anywhere between parents’ and you will child’s PA matchmaking due to the fact counted by pedometers
Of the 28 variables included in this study, 83 % were missing on at least one value (number of non-missing values for each variable is available in Table 1). Across cases/participants, 55 % were missing on at least one variable, and across the entire dataset, 13 % of the values were missing. Missing and non-missing cases were compared for check variables with >10 % missing data. Significant (p < .05) or marginally significant (p < .10) differences existed on parental BMI for parents' and children's steps/day. Importantly, families who participated in the initial assessment and those that returned the pedometers did not differ on parent self-reported leisure time MVPA (t = ?.67, p = .50) or children's parental-proxy reported PA (t = ?.38, p = .38). We therefore assumed at least a partial missing at random mechanism and imputed all of the missing data (including all covariates, predictor variables, criterion variables) using multiple imputation in SPSS. This procedure uses the fully conditional specification method and imputes data using linear regression for continuous variables and logistic regression for binary variables. We used 100 iterations, which resulted in 100 separate datasets . Relevant variables from the wider dataset (i.e., screen time, aerobic fitness, grip strength, dog ownership, walkability of neighborhood) were included as auxiliary variables.
We plus tested it dating on their own by-child and you will mother or father gender, son and you will mother or father pounds condition, sex homogeneity, pounds updates homogeneity, mother or father knowledge, household income, and you will city-height SES. Linear regressions were utilized to check on the study issues and you will partial roentgen shown perception dimensions. Cohen’s demanded effect types regarding small = .ten, average = .29, large = .fifty were used in order to interpret how big is consequences. The latest covariates for everyone analyzes was in fact kid decades, gender, and you will pounds position; parent intercourse, lbs updates, and you will knowledge; home income; area-top SES; and season. Each research provided between 11 and you may thirteen details. Depending on the IBM SPSS Analytics SamplePower 3, which have eleven covariates (medium joint impact size), you to definitely predictor variable (average impression size) and you will a communication label (brief effect size), 413 users have been necessary to choose consequences from the strength = .80 getting ? = .01. Thus we were good enough pushed for everybody analyses.
To address research questions 1 (whether parents’ steps/day was related to children’s steps/day), a linear regression was run with children’s steps/day as the criterion variable and parents’ steps/day and covariates as predictor variables. Coefficients were deemed significant at p < .05. To address research question 2 (potential moderators of the parent–child step/day relationship), children's steps/day was entered as the criterion variable and parent's steps/day and covariates as predictor variables. One by one we tested potential interactions including parent steps*child gender, parent steps*parent gender, parent steps*gender homogeneity, parent steps*child weight status, parent steps*parent weight status, parent steps*weight status homogeneity, parent steps*parent education, parent steps*household income, parent steps*area SES. In the models where the gender homogeneity and weight status homogeneity interactions were tested, these variables were also included as main effects. Before creating the interaction terms, the continuous variables (i.e., parent steps, area-level SES) were centered on their mean . To control for the increased probability of finding a significant result due to running multiple tests, a more stringent significance level was applied (p < .01) to the interactions. For significant or near significant interactions, a simple slopes analysis was performed to determine the beta coefficients and p-values for each group. Beta coefficients for the simple slopes were calculated by hand using the pooled results . The pooled results did not provide sufficient information to calculate the significance of the slopes by hand so the p-value (set at p < .05) was computed using the initial dataset (i.e., before the multiple imputation). To address research question 3 (parent–child PA relationship as measured by questionnaires), children's proxy-reported PA was entered as the criterion variable and parent self-reported leisure time MVPA and the covariates were entered as predictor variables. Coefficients were deemed significant at p < .05.