Discount Timing Half Cycle Factor Tool

Description

Use (index+0.5) years-of-cycle for midpoint or (index+1) for end timing and return the annual discount factor.

Health-economic costs depend on resource definitions, perspective, currency, price year, and timing. An incremental or discounted model term uses supplied assumptions without proving treatment benefit or determining an adoption decision.

Use (index+0.5) years-of-cycle for midpoint or (index+1) for end timing and return the annual discount factor.

When to use this tool

Use Discount Timing Half Cycle Factor when you need one transparent health-economic cost or comparison component.

How to use the tool and how it works

Enter annualRate, cycleYears, cycleIndex, useMidpoint. Use the units and conventions below.
Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
Read elapsedYears, factor. Use the output convention below.

Require annualRate above -1, nonnegative cycleYears, and nonnegative integer cycleIndex. Use (index+0.5) years-of-cycle for midpoint or (index+1) for end timing and return the annual discount factor.^[1]

Input field	Meaning and units	Accepted input
annualRate	Annual Rate	Required. Finite number; strictly above -1.
cycleYears	Cycle Years	Required. Finite number; minimum 0.
cycleIndex	Cycle Index	Required. Safe integer; minimum 0.
useMidpoint	Use Midpoint	Required. Boolean.

Output field	Interpretation	Returned shape
elapsedYears	Elapsed Years	Required. Finite number.
factor	Factor	Required. Finite number.

json

{
  "input": {
    "annualRate": 0.04,
    "cycleYears": 1,
    "cycleIndex": 0,
    "useMidpoint": true
  },
  "output": {
    "elapsedYears": 0.5,
    "factor": 0.9805806756909201
  }
}

Limitations and assumptions

Cycle index is zero-based and the duration is in years; the factor does not select an evaluation policy or apply itself to costs or outcomes.
Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Numeric signed-zero results are exported as zero.

Alternative or Complementary methods

Review the complete economic evaluation, clinical evidence, uncertainty, and relevant decision context separately.

References

Calculation and input contract: health-economics/discount-timing-half-cycle-factor — tool.io

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