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Abstract Background Despite the current trend towards large epidemiological studies of unrelated individuals, linkage studies in families are still thoroughly being utilized as tools for disease gene mapping. The use of the single-nucleotide-polymorphisms (SNP) array technology in genotyping of family data has the potential to provide more informative linkage data. Nevertheless, SNP array data are not immune to genotyping error which, as has been suggested in the past, could dramatically affect the evidence for linkage especially in selective designs such as affected sib pair (ASP) designs. The influence of genotyping error on selective designs for continuous traits has not been assessed yet. Results We use the identity-by-descent (IBD) regression-based paradigm for linkage testing to analytically quantify the effect of simple genotyping error models under specific selection schemes for sibling pairs. We show, for example, that in extremely concordant (EC) designs, genotyping error leads to decreased power whereas it leads to increased type I error in extremely discordant (ED) designs. Perhaps surprisingly, the effect of genotyping error on inference is most severe in designs where selection is least extreme. We suggest a genomic control for genotyping errors via a simple modification of the intercept in the regression for linkage. Conclusion This study extends earlier findings: genotyping error can substantially affect type I error and power in selective designs for continuous traits. Designs involving both EC and ED sib pairs are fairly immune to genotyping error. When those designs are not feasible the simple genomic control strategy that we suggest offers the potential to deliver more robust inference, especially if genotyping is carried out by SNP array technology.

The objective was to understand treatment patterns and persistence, and associated costs among type 2 diabetes (T2DM) patients starting glucagon-like peptide-1 receptor agonists (GLP-1 RAs) in routine clinical practice in Spain. T2DM patients >=18 years initiating a new treatment with the most widely used GLP-1 RAs, either once-weekly exenatide-QW, once-weekly dulaglutide, or once-daily liraglutide (index therapy) between 01/11/2015 and 30/06/2017 (index date) were included. The proportion of patients persistent at one year was highest among dulaglutide patients and lowest among exenatide-QW patients. [Extracted from the article]