Age-specific impact of COVID-19 on birth rates in Japan: An interrupted time-series analysis using national vital statistics
Fig 2
Trends in actual and predicted birth rates across different women’s age groups.
The overall indicates the results of women aged 15–49 years. The birth rate represents the number of births per 1,000 women. The vertical dashed line marks the cutoff point between the pre-pandemic and the post-pandemic periods. In contrast, the blue dashed line shows the predicted birth rates derived from pre-pandemic data and shows the counterfactual values. The shaded areas indicate 95% CIs of the predicted values. A quasi-Poisson regression model was applied to the pre-pandemic data, and the predicted number of births was calculated based on the model. In the quasi-Poisson regression model, the month and time point were included as explanatory variables to take into account of time and seasonal effects, and the logarithm of the women’s population was included as the offset term.