Temporal Trends in Mortality in Portugal, 1913-2022.

Abstract

Introduction: Demographic and epidemiological transitions have transformed mortality patterns, with declines observed up to the present. Long-term time series studies on mortality evolution in Portugal are scarce. We aimed to estimate and describe annual crude and age-standardized mortality rates (ASMRs) in Portugal from 1913 to 2022 and to analyse temporal trends from 1940.

Methods: A time series study was conducted using official statistics on deaths and resident population, between 1913 and 2022. Annual crude mortality rates (CMRs), overall and stratified by sex and age group, were calculated for the entire period. ASMRs were estimated for 1920, 1930, and the period from 1940 onwards. Trends in CMR and ASMR, overall and by sex, from 1940 onwards were analysed using joinpoint regression.

Results: Between 1913 and 2022, the annual CMR decreased by 42.1%. From 1940 to 2022, CMR decreased an average of 0.4% annually (95% CI: -0.5% to -0.3%). We observed a decrease during most of the study period for older age groups (≥60) and a substantial reduction in mortality in the youngest group (0-9 years), particularly in the early years under analysis and until the 1990s. The period 1940-1982 showed a decreasing trend, with a growing trend from 1982 to 2022. Sex-stratified analysis revealed different trends for men and women. Between 1920 and 2022, the overall ASMR declined by 70.9%. From 1940 to 2022, the ASMR had an average annual decrease of 1.4% (95% CI: -1.6% to -1.3%), interrupted in the 1960s and 2017-2022. Distinct temporal trends by sex were also identified between 1940 and 2022.

Conclusion: We showed an overall decreasing trend in CMR and ASMR, although with different magnitudes and trajectories during the study period. To the best of our knowledge, this is the first study to describe long-term trends in both crude and age-adjusted mortality rates in Portugal from 1940 to 2022, contributing to the knowledge on mortality.