PRO development: rigorous qualitative research as the crucial foundation

Recently published articles have described criteria to assess qualitative research in the health field in general, but very few articles have delineated qualitative methods to be used in the development of Patient-Reported Outcomes (PROs). In fact, how PROs are developed with subject input through focus groups and interviews has been given relatively short shrift in the PRO literature when compared to the plethora of quantitative articles on the psychometric properties of PROs. If documented at all, most PRO validation articles give little for the reader to evaluate the content validity of the measures and the credibility and trustworthiness of the methods used to develop them. Increasingly, however, scientists and authorities want to be assured that PRO items and scales have meaning and relevance to subjects. This article was developed by an international, interdisciplinary group of psychologists, psychometricians, regulatory experts, a physician, and a sociologist. It presents rigorous and appropriate qualitative research methods for developing PROs with content validity. The approach described combines an overarching phenomenological theoretical framework with grounded theory data collection and analysis methods to yield PRO items and scales that have content validity

The genetic architecture of the human cerebral cortex

The cerebral cortex underlies our complex cognitive capabilities, yet little is known about the specific genetic loci that influence human cortical structure. To identify genetic variants that affect cortical structure, we conducted a genome-wide association meta-analysis of brain magnetic resonance imaging data from 51,665 individuals. We analyzed the surface area and average thickness of the whole cortex and 34 regions with known functional specializations. We identified 199 significant loci and found significant enrichment for loci influencing total surface area within regulatory elements that are active during prenatal cortical development, supporting the radial unit hypothesis. Loci that affect regional surface area cluster near genes in Wnt signaling pathways, which influence progenitor expansion and areal identity. Variation in cortical structure is genetically correlated with cognitive function, Parkinson's disease, insomnia, depression, neuroticism, and attention deficit hyperactivity disorder

Cross-cultural validity of the thyroid-specific quality-of-life patient-reported outcome measure, ThyPRO

Background and purpose Thyroid diseases are common and often affect quality of life (QoL). No cross-culturally validated patient-reported outcome measuring thyroid-related QoL is available. The purpose of the present study was to test the cross-cultural validity of the newly developed thyroid-related patient-reported outcome ThyPRO, using tests for differential item functioning (DIF) according to language version., Methods The ThyPRO consists of 85 items summarized in 13 multi-item scales and one single item. Scales cover physical and mental symptoms, well-being and function as well as social and daily function and cosmetic concerns. Translation applied standard forward–backward methodology with subsequent cognitive interviews and reviews. Responses (N = 1,810) to the ThyPRO were collected in seven countries: UK (n = 166), The Netherlands (n = 147), Serbia (n = 150), Italy (n = 110), India (n = 148), Denmark (n = 902) and Sweden (n = 187). Translated versions were compared pairwise to the English version by examining uniform and nonuniform DIF, i.e., whether patients from different countries respond differently to a particular item, although they have identical level of the concept measured by the item. Analyses were controlled for thyroid diagnosis. DIF was investigated by ordinal logistic regression, testing for both statistical significance and magnitude (ΔR 2 &#60; 0.02). Scale level was estimated by the sum score, after purification., Results For twelve of the 84 tested items, DIF was identified in more than one language. Eight of these were small, but four were indicative of possible low translatability. Twenty-one instances of DIF in single languages were identified, indicating potential problems with the particular translation. However, only seven were of a magnitude which could affect scale scores, most of which could be explained by sample differences not controlled for., Conclusion The ThyPRO has good cross-cultural validity with only minor cross-cultural invariance and is recommended for use in international multicenter studies.,</p