Description
Average startUtility and endUtility and multiply by durationYears for qalys.
Health-economic utility models combine time with a supplied valuation scale. The reference anchors, duration units, survival basis, and discount timing determine the interpretation of each utility-year contribution.
Average startUtility and endUtility and multiply by durationYears for qalys.
When to use this tool
Use QALY One Interval Trapezoid Term when you need one explicit utility or modeled outcome component.
How to use the tool and how it works
- Enter startUtility, endUtility, durationYears. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read meanUtility, qalys. Use the output convention below.
Require nonnegative durationYears. Average startUtility and endUtility and multiply by durationYears for qalys.1
QALYs combine time and utility. This calculator contributes one supplied interval rather than establishing a complete economic evaluation or a clinical outcome.2
| Input field | Meaning and units | Accepted input |
|---|---|---|
| startUtility | Supplied dimensionless health-economic utility at the interval start. | Required. Finite number. |
| endUtility | Supplied utility on the same valuation basis at interval end. | Required. Finite number. |
| durationYears | Nonnegative duration in years on the model’s stated time basis. | Required. Finite number; minimum 0. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| meanUtility | Mean Utility | Required. Finite number. |
| qalys | Undiscounted utility-years for this one modeled interval. | Required. Finite number. |
{
"input": {
"startUtility": 0.6,
"endUtility": 0.8,
"durationYears": 2
},
"output": {
"meanUtility": 0.7,
"qalys": 1.4
}
}Limitations and assumptions
- Utilities use a common dimensionless preference scale and can be negative; this one-interval trapezoid assumes linear change, without survival adjustment, discounting, or patient-specific clinical assessment.
- 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
Check the complete evaluation model and source valuations; arithmetic utility values are not individual clinical assessments or judgments of personal worth.
References
-
Calculation and input contract: health-economics/qaly-one-interval-trapezoid-term — tool.io
-
Developing NICE Guidelines: Incorporating Economic Evaluation — National Institute for Health and Care Excellence
Similar or alternative tools
- Utility Interpolation Known Endpoint Contribution
Return linear endpoint weights summing to one and their weighted utility value.
- QALY Cycle Partial Duration Budget
Return coveredYears and utility times that duration as utilityYears.