CD4 and liver failure: Intervals chosen to maintain an adequate sample size, while roughly aligning with key changes in PWH treatment guidelines in Switzerland; categories: 2005–2007 (before Swiss Statement and the guideline to start ART independent of the CD4 cell count [‘treat-all’]), 2008–2010 (rollout of treat-all guidelines following the Swiss Statement), 2011–2013 (well-established treat-all guidelines), 2014–2016 (introduction of highly effective DAAs in HCV management in Switzerland), 2017–2019 (nationwide universal DAA access regardless of liver failure status), 2020–2022 (COVID-19 pandemic)