Age, period, and cohort effects on pulmonary function in a 24-year longitudinal study

Area of Science:

• Pulmonary Medicine
• Epidemiology
• Biostatistics

Background:

• Pulmonary function naturally declines with age.
• Understanding age, period, and cohort effects is crucial for interpreting lung function trends.
• Longitudinal studies provide valuable insights into population health changes over time.

Purpose of the Study:

• To estimate age, period, and cohort effects on pulmonary function using two-factor models.
• To analyze longitudinal data from a 24-year study in the Netherlands.
• To quantify the impact of aging on forced expiratory volume in 1 second (FEV1).

Main Methods:

• Utilized age-period and age-cohort models on 18,363 pulmonary function measurements from 6,148 subjects (aged 20-54).
• Data collected between 1965 and 1990, grouped into four birth cohorts and four survey periods.
• Statistical analysis to determine the significance of age, period, and cohort on FEV1.

Main Results:

• FEV1 declines with age, with significant acceleration of decline in both men and women.
• Younger birth cohorts exhibited higher average FEV1 levels compared to older cohorts.
• Significant positive period effects indicated increasing FEV1 in more recent survey periods for both sexes.

Conclusions:

• Age, period, and cohort significantly influence pulmonary function (FEV1).
• Observed improvements in lung function over time may be linked to environmental and lifestyle changes.
• The study highlights the importance of considering multiple factors in lung health research.