On the resilience of health systems: A methodological exploration across countries in the WHO African Region by Karamagi, HC, Titi-Ofei, R, Kipruto, HK, Seydi, AB-W, Droti, B, Talisuna, A, Tsofa, B, Saikat, S, Schmets, G, Barasa, E, Tumusiime, P, Makubalo, L, Cabore, JW, Moeti, M