To determine the time pattern of adolescent fertility rates (AFRs) in the countries of the Region of the Americas, categorizing them to evaluate their mobility and differences, and to produce a forecast for 2023.
Ecological and descriptive study of a time series of AFRs in 32 countries, from 1960 to 2019, based on information from the World Bank and the Pan American Health Organization (PAHO). Trends in the AFR were estimated using a linear regression model (Prais-Winsten method). Differences were evaluated between two subperiods (1960-1989 and 1990-2019) and among four categories of the AFR for 2019 by testing related samples and analysis of variance, respectively. The AFR for 2023 was predicted with autoregressive integrated moving average (ARIMA) models.
The AFR time series for the sample was non-stationary and the annual average trend was downward (coefficient = -1.173; p < 0.001; R2 adjusted = 0.968), dropping from 124 per 1 000 in 1960 to 56.1 per 1 000 in 2019. The countries with the largest and smallest annual trend were Saint Vincent and the Grenadines (-2.783) and Argentina (0.017). Between subperiods (1960-1989 compared to 1990-2019) there were no statistically significant differences between the AFR in Uruguay and Argentina, but there were significant differences among the four categories of AFR for 2019. The average AFR for the sample should continue declining to 2023, but it could increase in eight countries.
The time series is largely non-stationary, with a downward trend to 2023. There has been an uneven decline in AFRs, with significant differences among the four groups of countries categorized by their AFR in 2019. The lowest AFRs correspond to two countries in North America, five in the non-Latin Caribbean, and one in South America. The highest AFRs correspond to countries in the Latin Caribbean and in Central and South America.