Optimatization of pellet preparation is CF-granulator with factorial design

Lithium carbonate-containing pellets were made in a laboratory-scale centrifugal granulator in order to investigate the effects of the process parameters (rotor rotation speed, slit airflow rate and spray air rate) on the pellet shape and size distribution. The size distribution and the shape parameters (roundness, roughness, rectangularity and sphericity) of the pellets were measured, and an optimization parameter was then calculated from these shape parameters. The experiment was carried out and evaluated according to a 2(3) full factorial design. All three variables were found to exert a significant effect on the pellet shape. With use of the signs and magnitudes of the coefficients of the variables in the fitted linear model, the direction of the gradient was determined; two control measurements were made. These proved the accuracy of the applied model and the direction of the gradient. Overall, a high rotor rotation speed and low slit airflow rate and spray air rate furnished the best value of the optimization parameter.     

Comparing the psychometric properties of the EQ-5D-3L and EQ-5D-5L descriptive systems and utilities in atopic dermatitis

Background

Atopic dermatitis (AD) is a common chronic inflammatory skin disorder affecting up to 10% of adults. The EQ-5D is the most commonly used generic preference-accompanied measure to generate quality-adjusted life years (QALYs) for economic evaluations.

Objectives

We aimed to compare psychometric properties of the three-level and five-level EQ-5D (EQ-5D-3L and EQ-5D-5L) in adult patients with AD.

Methods

In a multicentre cross-sectional study, 218 AD patients with a broad range of severity completed the EQ-5D-3L, EQ-5D-5L, Dermatology Life Quality Index (DLQI) and Skindex-16. Disease severity outcomes included the Investigator Global Assessment, Eczema Area and Severity Index and the objective SCORing Atopic Dermatitis.

Results

A good agreement was established between the two EQ-5D versions with an intraclass correlation coefficient of 0.815 (95% CI 0.758–0.859, p < 0.001). Overall, 33 different health state profiles occurred in the EQ-5D-3L and 84 in the EQ-5D-5L. Compared to the EQ-5D-3L, ceiling effect was reduced for the mobility, self-care, usual activities and pain/discomfort dimensions by 4.6–11.5%. EQ-5D-5L showed higher average relative informativity (Shannon’s evenness index: 0.64 vs. 0.59). EQ-5D-5L demonstrated better convergent validity with EQ VAS, DLQI and Skindex-16. The two measures were similar in distinguishing between groups of patients based on disease severity and skin-specific quality of life with a moderate or large effect size (η² = 0.083–0.489).

Conclusion

Both instruments exhibited good psychometric properties in AD; however, the EQ-5D-5L was superior in terms of ceiling effects, informativity and convergent validity. We recommend the use of the EQ-5D-5L to measure health outcomes in clinical settings and for QALY calculations in AD.