Educational strategies to improve health literacy for people with type 2 diabetes in low socio-economic communities: A realist review protocol - Namalambo Mwenda - Ng’uni; Martin Heine; Fastone Goma; Monika Martens; Miriam Mapulanga - Lisulo; Brown Kamanga; Inonge Milupi; Susan Hanekom (PLoS ONE, 2026)