Forecasting Age-Specific Fertility Rates Between Age 15-19 in Sri Lanka: A Time Series Analysis (2022-2026)

Abstract

Fertility is the main factor in human reproduction, influencing various outcomes. Teenagers, while biologically mature enough to engage in intercourse and become pregnant, may lack the psychological maturity to handle the responsibilities of an active sexual life. Global health recognises teenage pregnancy as a challenge. In Sri Lanka, traditional law allows females under 12 years old to marry despite the legal age of 18. According to the Ministry of Health, Sri Lanka (2022), poverty, poor education, fewer employment opportunities, a knowledge gap, and misconceptions about contraception methods cause teenage pregnancy. Pregnancy and childbirth are the leading causes of death among females aged 15 - 19, with higher health risks. The study aimed to identify the trend of age-specific fertility rates (ASFR) in Sri Lankan females aged 15-19 and forecast future ASFR. ASFR data related to the age category from 1960 to 2021 were extracted from the World Bank Development Indicator as the secondary data source. Time series analysis was utilised with RStudio statistical software. There was a decreasing trend in ASFR over the period. The Zivot & Andew unit root test confirmed that the series was stationary at the second difference. The orders of ARIMA model parameters were selected using ACF and PACF plots. The most fitted model was chosen based on the Akaike Information Criterion (AIC). The estimated parameters for the fitted model ARIMA (0, 2, 1) were -0.6844 for MA (1) with a standard error of 0.1270. The fitted model was 1 0.6844 t t Y  − = − . The estimated ASFR (15-19) in Sri Lanka from 2022 to 2026 were 13.3318, 12.5633, 11.7947, 11.0260, and 10.2575. It is recommended to implement reproductive health and maternity care programmes focusing on the decreasing trends in ASFR. A comprehensive strategy should be devised to educate teenagers about contraceptive usage, prevent unexpected births, and enhance their educational prospects.