Neonatal mortality in Kenyan hospitals: a multisite, retrospective, cohort study by Irimu, G, Aluvaala, J, Malla, L, Omoke, S, Ogero, M, Mbevi, G, Waiyego, M, Mwangi, C, Were, F, Gathara, D, Agweyu, A, Akech, S, English, M, Clinical Information Network authors