Period effects reflect diagnostic expansion and cohort effects reflect improving respiratory exposure for self-reported chronic lung disease: a harmonised age–period–cohort analysis of seven ageing cohorts across three continents
Abstract
Abstract Background Age–period–cohort (APC) analyses are increasingly used to interpret temporal trends in self-reported chronic lung disease (CLD), but period and cohort effects may reflect different mechanisms, including changes in diagnostic access and long-term exposure profiles. We examined these patterns using harmonised ageing cohorts across multiple world regions. Methods We analysed 1,019,588 person-wave observations from adults aged 50–95 years in seven ageing cohorts from the United States, England, continental Europe, China, Korea, Mexico, and India, covering survey years from 2000 to 2023. The primary outcome was self-reported physician-diagnosed CLD. Asthma was analysed as a secondary outcome in cohorts with available data. Bayesian APC models were fitted using integrated nested Laplace approximation. Country-specific period effects were compared with national smoking prevalence, ambient PM2.5 concentration, gross domestic product per capita, and health expenditure per capita. Results Age effects increased with age and reached a plateau in later life. Period effects rose over calendar time, especially after 2010. By contrast, cohort effects declined among generations born after the mid-1940s. This cohort pattern was seen in most countries and was partly reproduced for asthma. In most multi-wave countries, increasing period effects occurred during periods of declining smoking prevalence and rising GDP and health expenditure per capita. Korea showed a different…
How strong is the evidence?
Evidence Hub reads this as a cohort study, done in people. Its evidence level is 3 of 5 (Moderate · trial / cohort / secondary analysis). Trials without a large randomized design, cohorts and secondary analyses give moderate evidence.
Read the paper
Related studies
- Understanding the factors influencing fall armyworm (Spodoptera frugiperda J.E. Smith) damage in African smallholder maize fields and quantifying its impact on yield. A case study in Eastern Zimbabwe
- Alarming situation of emerging H5 and H7 avian influenza and effective control strategies
- Livestock and food security: vulnerability to population growth and climate change
- Atmosphere–ocean oxygen and productivity dynamics during early animal radiations
- Characterization of the global distribution and diversified plasmid reservoirs of the colistin resistance gene mcr-9
- The global seroprevalence of Toxoplasma gondii in pigs: A systematic review and meta-analysis
Go deeper in Evidence Hub
Evidence Hub adds a study data sheet (design, sample size, evidence level, key numbers), an AI summary and a chat grounded in the paper's text.