Sonja Mensch

118 Chapter 6 means that high scores on motor abilities often co-occur with high scores on quality of life; this is also the case for low scores. Independent relationships between motor abilities and QoL were tested using multiple linear regression analysis models with the QoL dimensions (dependent variables) that correlated significantly with Movakic sub- scores on body positions (independent variables). In model 1 gender, age and GMFCS- scores were entered into the equation after which inmodel 2 theMovakicmotor abilities total and subscale scores were entered into the equation. In order to control for the covariates gender, age and GMFCS-score, explained variance (R square) was calculated for both models. The uniquely explained variance in QoL scores using only the Movakic scores can now be calculated by subtracting the R square of the total model (model 2) from the model that only uses the covariates (model 1). Multicollinearity was tested using the variance inflation factor (VIF); multicollinearity was considered to be present if VIF was higher than 10. P-values of .05 or smaller were considered to indicate statistical significance. All analyses were done using SPSS/PASW Statistics version 21 (SPSS Inc, Chicago, Illinois). RESULTS Movakic and QoL-PMD were measured within a period of 2-12 weeks (mean 7.2 weeks); no meaningful events were recorded within this measurement interval for any child. Bivariate correlations between Movakic and QoL subscales and total scores are shown in Table 2. A significantly moderate high correlation ( r =0.40, p =0.03) between total Movakic score and total QoL-PMD score was shown. Significant bivariate moderate correlations were also found between the total Movakic score and the QoL-PMD dimensions Physical Well-Being, Development and Activities. Motor abilities in the lying and sitting body position were significantly positively correlated with the QoL- PMD dimension Development (moderately to substantially). Motor abilities in the sitting body position were also significantly positively correlated (moderately) to the dimension Physical Well-being and total QoL-PMD score. Motor abilities in the standing body position had a strong significant positive correlation to the dimension Activities and total QoL-PMD score. Mean QoL-PMD and Movakic scores as well the results of the multiple regression analysis are reported inTable 3. As significant bivariate correlations were found between total Movakic score and the QoL-PMD dimensions Physical Well-Being, Development and Activities and between Movakic body position scores and these same QoL-PMD dimensions, these QoL dimensions were used for the multiple regression analyses. The scores within the Physical Well-being, Development and Activities dimensions