Dealing with Time in Health Economic Evaluation: Methodological Issues and Recommendations for Practice

Area of Science:

• Health economics
• Biostatistics
• Clinical trial design

Background:

• Time is a critical factor in health economic evaluations, influencing costs and effects.
• The timing and duration of interventions and outcomes significantly impact model results.
• Current health economic models often require careful consideration of temporal aspects.

Purpose of the Study:

• To provide a methodological overview of key temporal considerations in health economic modeling.
• To offer recommendations for designing and interpreting health economic models regarding time.
• To address cohort selection, time simulation, and discounting in cost-effectiveness analyses.

Main Methods:

• Review of time-related issues in health economic modeling.
• Discussion of discrete-time vs. continuous-time models and cycle length selection.
• Guidance on converting rates and probabilities and discounting future costs and effects.

Main Results:

• Recommendations for selecting cohorts based on cost-effectiveness variations and subgroup feasibility.
• Preference for short cycles or continuous-time models to mitigate bias and avoid half-cycle corrections.
• Emphasis on transparent reporting and understanding the rationale for discounting methods, including differential discounting.

Conclusions:

• Explicitly stating and justifying modeling choices regarding time is crucial for robust health economic evaluations.
• Analysts should consider the impact of alternative temporal modeling decisions on results.
• Adherence to methodological best practices in time simulation enhances the reliability of cost-effectiveness analyses.