Yang, Keming

AbstractBackground and AimWe aim to systematically investigate gastrointestinal (GI) hospitalizations in the United States during the early phase of the COVID‐19 pandemic on a national level and the consequence that may inform practice and policies.MethodsA retrospective cross‐sectional analysis of adult hospitalizations with GI‐related diagnoses or procedures in the United States in 2020 was used, with hospitalizations from 2016 to 2019 used for contextual information.ResultsHospitalizations with principal and secondary GI diagnoses decreased by 13.3% and 8.2% from 2019 to 2020, respectively. Most GI diagnoses decreased in 2020, with a few exceptions including alcoholic liver disease (increased by 7.8% as a principal diagnosis) and acute liver failure (increased by 11.6% as a secondary diagnosis). The mortality rate of hospitalizations with GI disease increased in 2020 compared with 2019 (for principal diagnosis: adjusted odds ratio 1.08, 95% confidence interval 1.03–1.13, P = 0.001; for secondary diagnosis: adjusted odds ratio 1.10, 95% confidence interval 1.07–1.13, P < 0.001). Most GI procedures decreased except for a notable 8.3% increase in gastrostomy. The per‐GI‐hospitalization rate of procedures increased for hospitalizations with a principal GI diagnosis (56.4% vs 55.6%, P = 0.003) or unchanged for hospitalizations with secondary GI diagnoses (18.3% vs 18.2%, P = 0.512).ConclusionThe COVID‐19 pandemic resulted in a decrease in the volume of GI hospitalizations and procedures in 2020, but there was an increase in the mortality rate and some specific diagnoses including alcoholic liver disease and acute liver failure. These findings will likely enlighten future research and healthcare resource allocation for GI diseases.

Abstract Background Mendelian randomization (MR) studies are susceptible to metadata errors (e.g. incorrect specification of the effect allele column) and other analytical issues that can introduce substantial bias into analyses. We developed a quality control (QC) pipeline for the Fatty Acids in Cancer Mendelian Randomization Collaboration (FAMRC) that can be used to identify and correct for such errors. Methods We collated summary association statistics from fatty acid and cancer genome-wide association studies (GWAS) and subjected the collated data to a comprehensive QC pipeline. We identified metadata errors through comparison of study-specific statistics to external reference data sets (the National Human Genome Research Institute-European Bioinformatics Institute GWAS catalogue and 1000 genome super populations) and other analytical issues through comparison of reported to expected genetic effect sizes. Comparisons were based on three sets of genetic variants: (i) GWAS hits for fatty acids, (ii) GWAS hits for cancer and (iii) a 1000 genomes reference set. Results We collated summary data from 6 fatty acid and 54 cancer GWAS. Metadata errors and analytical issues with the potential to introduce substantial bias were identified in seven studies (11.6%). After resolving metadata errors and analytical issues, we created a data set of 219 842 genetic associations with 90 cancer types, generated in analyses of 566 665 cancer cases and 1 622 374 controls. Conclusions In this large MR collaboration, 11.6% of included studies were affected by a substantial metadata error or analytical issue. By increasing the integrity of collated summary data prior to their analysis, our protocol can be used to increase the reliability of downstream MR analyses. Our pipeline is available to other researchers via the CheckSumStats package (https://github.com/MRCIEU/CheckSumStats).