What does the time horizon in economic evaluation refer to?

• A. The period over which costs and outcomes are measured to capture relevant effects
• B. The timeframe of the study funding
• C. The maximum follow-up allowed by guidelines
• D. The duration of the drug's patent

Answer: (B)

The time horizon in economic evaluation is the period over which costs and health outcomes are measured to capture all relevant effects of the options being compared. It matters because many benefits or harms may appear years after an intervention starts, so choosing a horizon long enough to reflect those differences is essential. For chronic diseases or lifelong treatments, a lifetime horizon is often appropriate; for short-term or acute interventions, a shorter horizon may be enough if it still covers the key differences in costs and effects. It’s not about how long the study is funded, a guideline’s maximum follow-up, or the patent duration of a drug—the horizon is about the span used to capture all meaningful consequences in the analysis.