Using Separate Single-Outcome Risk Presentations Instead of Integrated Multioutcome Formats Improves Comprehension in Discrete Choice Experiments.

INTRODUCTION: Despite decades of research on risk-communication approaches, questions remain about the optimal methods for conveying risks for different outcomes across multiple time points, which can be necessary in applications such as discrete choice experiments (DCEs). We sought to compare the effects of 3 design factors: 1) separated versus integrated presentations of the risks for different outcomes, 2) use or omission of icon arrays, and 3) vertical versus horizontal orientation of the time dimension. METHODS: We conducted a randomized study among a demographically diverse sample of 2,242 US adults recruited from an online panel (mean age 59.8 y, s = 10.4 y; 21.9% African American) that compared risk-communication approaches that varied in the 3 factors noted above. The primary outcome was the number of correct responses to 12 multiple-choice questions asking survey respondents to identify specific numbers, contrast options to recognize dominance (larger v. smaller risks), and compute differences. We used linear regression to test the effects of the 3 design factors, controlling for health literacy, graph literacy, and numeracy. We also measured choice consistency in a subsequent DCE choice module. RESULTS: Mean comprehension varied significantly across versions (P < 0.001), with higher comprehension in the 3 versions that provided separated risk information for each risk. In the multivariable regression, separated risk presentation was associated with 0.58 more correct responses (P < 0.001; 95% confidence interval: 0.39, 0.77) compared with integrated risk information. Neither providing icon arrays nor using vertical versus horizontal time formats affected comprehension rates, although participant understanding did correlate with DCE choice consistency. CONCLUSIONS: In presentations of multiple risks over multiple time points, presenting risk information separately for each health outcome appears to increase understanding. HIGHLIGHTS: When conveying information about risks of different outcomes at multiple time points, separate presentations of single-outcome risks resulted in higher comprehension than presentations that combined risk information for different outcomes.We also observed benefits of presenting single-outcome risks separately among respondents with lower numeracy and graph literacy.Study participants who scored higher on risk understanding were more internally consistent in their responses to a discrete choice experiment.

Web-based versus paper administration of common ophthalmic questionnaires: comparison of subscale scores.

OBJECTIVE: To compare participants' responses to Web-based and paper-and-pencil versions of an ophthalmic, patient-reported outcome (PRO) questionnaire. DESIGN: Questionnaire development. PARTICIPANTS: Matched subjects with ocular surface disease (OSD) (n = 68) and without OSD (controls, n = 50). METHODS: Subjects completed a standard, paper-and-pencil and a Web-based version of the same questionnaire in randomized order. The administered questionnaire included several ophthalmic PRO subscales: the National Eye Institute's (NEI's) Refractive Error Quality of Life Instrument's Clarity of Vision, Near Vision, Far Vision, Glare, Symptoms, Worry, and Satisfaction with Correction subscales; the Ocular Surface Disease Index's (OSDI's) Symptoms subscale; and the NEI's Visual Function Questionnaire's Driving subscale. Possible scores for each subscale ranged from 0 (no difficulty) to 100 (most difficulty). Agreement of subscale scores between modes of administration was assessed using the Bland-Altman approach and multivariable logistic regression. MAIN OUTCOME MEASURES: Subscale scores and an unweighted average total score for each mode of administration. RESULTS: Mean differences in scores between modes of administration ranged from -2.1 to +2.3 units. Although no differences were found to be statistically significant, the Worry and Satisfaction with Correction subscales approached statistical significance (P = 0.07 and 0.08, respectively). Although most subscale mean differences in score did not differ significantly by gender, age (≥40 vs. <40 years), disease status (OSD vs. control), order of administration, or time between completion of the questionnaires, women had slightly greater score differences than men for the Driving (P = 0.04) and Clarity of Vision (P = 0.03) subscales; those with OSD had greater score differences for Clarity of Vision than did controls (P = 0.0006); and those aged ≥40 years had slightly greater differences in OSDI Symptoms subscale than those aged <40 years (P = 0.04). CONCLUSIONS: To our knowledge, this Food and Drug Administration and NEI collaboration is the first study to evaluate the equivalence of Web-based and paper versions of ophthalmic PRO questionnaires. We found no evidence of clinically significant differences between scores obtained by the 2 modes for any of the examined subscales. A Web-based instrument should yield scores equivalent to those obtained by standard methods, providing a useful tool that may facilitate ophthalmic innovation. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Material properties that predict preservative uptake for silicone hydrogel contact lenses.

OBJECTIVES: To assess material properties that affect preservative uptake by silicone hydrogel lenses. METHODS: We evaluated the water content (using differential scanning calorimetry), effective pore size (using probe penetration), and preservative uptake (using high-performance liquid chromatography with spectrophotometric detection) of silicone and conventional hydrogel soft contact lenses. RESULTS: Lenses grouped similarly based on freezable water content as they did based on total water content. Evaluation of the effective pore size highlighted potential differences between the surface-treated and non-surface-treated materials. The water content of the lens materials and ionic charge are associated with the degree of preservative uptake. CONCLUSIONS: The current grouping system for testing contact lens-solution interactions separates all silicone hydrogels from conventional hydrogel contact lenses. However, not all silicone hydrogel lenses interact similarly with the same contact lens solution. Based upon the results of our research, we propose that the same material characteristics used to group conventional hydrogel lenses, water content and ionic charge, can also be used to predict uptake of hydrophilic preservatives for silicone hydrogel lenses. In addition, the hydrophobicity of silicone hydrogel contact lenses, although not investigated here, is a unique contact lens material property that should be evaluated for the uptake of relatively hydrophobic preservatives and tear components.