R.J.A. de Kinderen

A randomized controlled trial of the ketogenic diet in refractory childhood epilepsy

To evaluate the efficacy and tolerability of the ketogenic diet (KD) during the first 4 months of a randomized controlled trial (RCT) in refractory epilepsy patients aged 1–18 years.

Discrete-choice experiments versus rating scale exercises to evaluate the importance of attributes

Aim: To examine the difference between discrete-choice experiments (DCE) and rating scale exercises (RSE) in determining the most important attributes using a case study. Methods: Undergraduate health sciences students were asked to complete a DCE and a RSE. Six potentially important attributes were identified in focus groups. Fourteen unlabelled choice tasks were constructed using a statistically efficient design. Mixed multinomial logistic regression analysis was used for DCE data analysis. Results: In total, 254 undergraduate students filled out the questionnaire. In the DCE, only four attributes were statistically significant, whereas in the RSE, all attributes except one were rated four or higher. Conclusion: Attribute importance differs between DCE and RSE. The DCE had a differentiating effect on the relative importance of the attributes; however, determining relative importance using DCE should be done with caution as a lack of statistically significant difference between levels does not necessarily imply that the attribute is not important.

Reporting health care decision models: a prospective reliability study of a multidimensional evaluation framework

ABSTRACT The aim of this study was to evaluate the inter-rater reliability of the Phillips-checklist, a proposed framework for the quality assessment of modeling studies. Six raters evaluated nine modeling studies from three different medical specialties. Intra-class correlation (ICC) and corresponding variance components were estimated from these studies. Raters were asked to comment on their experience with the framework. While overall the mean inter-rater reliability showed no significant rater-effect (ICC = 0.69, p = 0.064), there was – presumably as a result of a lower study variability – a significant rater effect for clopidogrel only (p < 0.001). The framework allowed a more structured methodological assessment but several items remained unclear. Regarding the quality assessment of modeling studies with the proposed framework, the rater variability is similar or even higher than variability because of studies or residual effects. Several scoring items can and should be improved to ease interpretation.