Determinants of Duration of the First Birth Interval Using the Semi-parametric Survival Model in Uttar Pradesh, India: Evidence from NFHS – 5 (2019-2021)

Background: First birth is an important phenomenon in women life. It not only affects the duration of rest intervals but also reproductive pattern women. The study aims to explore determinants first interval. Subjects dan Method: cross-sectional data 33,275 married between years 2005-2021 aged (15-49) from Uttar Pradesh, were selected NFHS-5 data. sample a stratified two-stage sample. Socio-demographic, socio-economic and cultural factors taken as independent variables. dependent variable was interval variable. Data analysis performed on SPSS version 23 software R Programming language for graphical representation. Cox proportional hazard models applied analysis. Results: mean age at marriage 19.4; SD=3.26 21.39; SD=3.24 years. median was22 months with IQR 14 until 32 months. revealed that religion, residence, (ever) fetal loss, birth, heard family planning, or husband education found be statistically significant associated (p<0.001). Conclusion: There need change mindset people towards concept use planning methods increase length interval, regardless various factors. This would help improve health children, well reduce population growth. Keywords: semi-parametric, cox model, plot. Correspondence: Jai Kishun, Department Biostatistics Health Informatics, Sanjay Gandhi Postgraduate Institute Medical Sciences. Lucknow – 226014, India; email: [email protected]. Mobile: Journal Epidemiology Public (2023), 08(01): 1-14 https://doi.org/10.26911/jepublichealth.2023.08.01.01.