Fig. 5

Evolution of \(\widehat{{\text{R}\text{R}\text{I}}_{\text{j}}}\) over time (4 October 2021–26 December 2021) and by age group j (age 0–5, 6–11, 12–17, 18–29, 30–64, 65+) in Belgium, based on OI considering all tests (green line), OI considering only targeted tests (orange line), PR considering all tests (blue line), and PR considering only screening tests before hospital admission (pink line)