56 Chapter 3 Next, data from different locations were combined to calculate Z-scores on country level (Table 2). In the Netherlands, the Z-score was 4.48 (p=7.3 x 10-6), and in the UK, the Z-score was -2.58 (p=0.01). When combining all available data, there was no significant Z-score (-0.46, p=0.64). Location Z-score P value England -0.57 0.57 Scotland -0.94 0.35 Wales -0.92 0.36 UK -2.58 0.01 NL 4.48 7.3 x 10-6 All -0.46 0.64 Table 2: Z-scores for the difference in SD for the rate of elevated AST or ALT in the period of interest (cases presenting with non A-E hepatitis) and the baseline period (pre-2020), for 3-week to 5-year-olds, and the corresponding P values. UK consists of the results of England, Scotland and Wales combined. Primary care data The number of recorded liver function tests decreased following the onset of the COVID-19 pandemic. The rate of AST tests remained below pre-pandemic levels in those aged 21-30 and 11-20, but recovered in other age groups (Supplementary Figure 7). Consistent with our findings in the pragmatic analysis, there was no evidence of a rise in abnormal liver function test results during the period of interest (Supplementary Figure 8). An accompanying report for these results is openly available at reports.opensafely.org16. Discussion Summary Our approach of sharing a simple software tool for local use enabled rapid, federated data analytics across 30 clinical centres in three countries. In the Netherlands, we found an increase in elevated AST and ALT tests in 3-week to 5-year-olds in the period of interest, possibly caused by a larger outbreak of milder cases of hepatitis, mainly in Utrecht. In all the other locations, we found no evidence for a large outbreak of milder cases of hepatitis corresponding to the outbreak period, and we did not observe any clear indication of changes in primary care activity or test results in the same period.
RkJQdWJsaXNoZXIy MTk4NDMw