Clarifying assumptions in age-period-cohort analyses and validating results

Area of Science:

• Epidemiology
• Population Sciences
• Biostatistics

Background:

• Age-period-cohort (APC) models are frequently used in epidemiology and population sciences to analyze health trends.
• The application of APC models is contentious due to inconsistent analytical assumptions and inadequate result evaluation.
• These inconsistencies lead to conflicting conclusions and confusion regarding APC methodologies.

Purpose of the Study:

• To introduce research guidelines for articulating analytical assumptions in APC models.
• To demonstrate the utility of these guidelines in validating APC model results.
• To address the contentiousness surrounding APC methods in scientific research.

Main Methods:

• Developed and applied research guidelines to practitioners of APC methods.
• Utilized a 2015 American Journal of Epidemiology study on U.S. heart disease mortality trends for demonstration.
• Evaluated the consistency and robustness of different APC methods under the proposed guidelines.

Main Results:

• Some APC methods yield results highly sensitive to researcher manipulation.
• Other APC methods produce results that are robust and consistent across different models.
• The application of guidelines highlighted significant differences in method stability.

Conclusions:

• The proposed guidelines are simple and effective in resolving disagreements over APC model results.
• Cautious application of APC models with these guidelines can yield consistent and robust findings.
• Adherence to the guidelines can reduce the publication of variable and conflicting results in APC studies.