International Journal of Public Health and Safety

A primary focus of Survival analysis in medicine is modelling time to surviving of a particular disease. In this paper, survival analysis was carried out on the neonatal jaundice data modeling time to surviving the disease. The data was gotten from collected from University College hospital (UCH), Ibadan, Nigeria. The Kaplan-Meier approach was used to describe the survival functions of the neonatal jaundice patients and Log-rank tests was used to compare the survival curves among groups. Different kinds of models such as Cox Proportional Hazard Model and Accelerated Failure Time (AFT) models like Weibull AFT model, Logistic AFT model, Log-normal AFT model, Log-logistic AFT model and Exponential AFT model are considered to be used for modelling the time to surviving neonatal jaundice. Models selection criteria were used as a guide to unravel the best model for modeling neonatal jaundice. The result revealed that the fitted cox proportional hazard model suggested that there were 0.2708 chances of male neonates having higher median time of surviving jaundice compared to female neonates. Based on the mother's health history, neonates whose mother had illness during pregnancy will have 0.5329 chance of having higher median time of surviving the Jaundice compared to neonates whose mother do not have any illness during pregnancy. The log-logistic AFT model out-performed the other models since it has the lowest AIC and the highest log-likelihood value with 1131.461 and -550.7305 respectively.

Microbial quality of Tilapia Fish Samples during frozen storage at -18°C for 180 days and their fried products were determined. Total viable counts of bacteria were 2.25×10⁴ and 1.7×10⁴ cfu/g for farm A and B respectively. Yeast and Mold counts (Y&M) were 9.5×10² and 4.66×10² cfu/ g for farms A and B samples, respectively. Total viable counts of frozen tilapia fish samples increased to 3.13 and 3.93 ×10⁴ cfu/g after 60 days of storage for farms A and B, respectively, then decreased to 0.7 and 0.66×10⁴ cfu/g after 120 days of storage for farms A and B, respectively, then increased to 4.26 and 2.43×10⁴ cfu/g for frozen stored samples from farms A and B, respectively at the end of storage period. After frying the total viable counts increased in samples at zero time, and then decreased with storage periods of raw frozen samples until the end of frozen storage. After the frying process the counts of Y&M increased in all samples at the storage periods, while the fried samples from farm B decreased to 14.66×10² cfu/g after 60 days raw storage. At the end of storage the counts of thermophilic bacteria increased to 17 and 12 (×10³ cfu/g) for fried samples from farms A and B, respectively.