Description
Return a cohort survival share with a zero-initial-count flag.
Population records distinguish cohort balances, time exposure, survival expectations and observation coverage. Exact arithmetic can preserve counts while the definitions, exclusions and missingness still need independent verification.
Return a cohort survival share with a zero-initial-count flag.
When to use this tool
Use Age Band Survival Share when checking an explicit cohort record or exposure-support convention.
How to use the tool and how it works
- Enter survivors, initial. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read share, defined. Inspect defined before interpreting the associated values.
Return a cohort survival share with a zero-initial-count flag. Require nonnegative whole initial and survivors <= initial; divide survivors/initial when positive, otherwise zero and defined = false.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| survivors | Survivors | Required. Safe integer; minimum 0. |
| initial | Initial | Required. Safe integer; minimum 0. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| share | survivors/initial, or zero when defined is false; no survival model is fitted. | Required. Finite number. |
| defined | Whether the stated denominator is nonzero; inspect this before using the associated ratio. | Required. Boolean. |
{
"input": {
"survivors": 80,
"initial": 100
},
"output": {
"share": 0.8,
"defined": true
}
}Limitations and assumptions
- Zero cohort size is undefined, and the proportion does not estimate individual prognosis or censoring effects.
- 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
Use suitable population and event data, including censoring and coverage evidence, for demographic inference beyond local bookkeeping.
References
Similar or alternative tools
- Cohort Survival Exposure Share
Return observed support within survival-weighted exposure.
- Pension Month Coverage Denominator
Return pension-month coverage under an unknown-month policy.