TY - JOUR AU - Ramjith, Jordache AU - Roes, Kit C.B. AU - Zar, Heather J. AU - Jonker, Marianne A. PY - 2021 DA - 2021/01/11 TI - Flexible modelling of risk factors on the incidence of pneumonia in young children in South Africa using piece-wise exponential additive mixed modelling JO - BMC Medical Research Methodology SP - 17 VL - 21 IS - 1 AB - Recurrent episodes of pneumonia are frequently modeled using extensions of the Cox proportional hazards model with the underlying assumption of time-constant relative risks measured by the hazard ratio. We aim to relax this assumption in a study on the effect of factors on the evolution of pneumonia incidence over time based on data from a South African birth cohort study, the Drakenstein child health study. SN - 1471-2288 UR - https://doi.org/10.1186/s12874-020-01194-6 DO - 10.1186/s12874-020-01194-6 ID - Ramjith2021 ER -