Rate-Term Selector
Select incidence or prevalence terminology and calculate the supplied rate.
Description
Incidence and prevalence describe different event-count bases.
Incidence and prevalence describe different event-count bases. This selector labels the supplied basis while scaling a count to a population rate.1
Select incidence or prevalence terminology and calculate the supplied rate.
When to use Rate-Term Selector
Use this tool to select incidence or prevalence terminology and calculate the supplied rate.
Prepare the text, recorded observations, aligned figures or editorial criteria requested. Confirm what each label, count, timestamp or supplied flag represents before interpreting the result.
How to use Rate-Term Selector and understand its results
- Prepare the text, recorded observations, aligned figures or editorial criteria requested. Confirm what each label, count, timestamp or supplied flag represents before interpreting the result.
- Enter countsNewEvents, countsExistingCases, events, population, scale using the field table and calculation rules, then run the tool.
- Read recommendedTerm, calculatedRate. The explanation below defines the units, signs, ordering and any flags or placeholder values.
- If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.
| Input field | Meaning | Value type; see rules below | Requirement |
|---|---|---|---|
| countsNewEvents | Measure counts new events | boolean | Required |
| countsExistingCases | Measure counts existing cases | boolean | Required |
| events | Event count | number; minimum: 0 | Required |
| population | Population at risk | number; minimum: 0 | Required |
| scale | Rate scale | number; minimum: 0 | Required |
Enter nonnegative events, positive population/scale and two booleans identifying new and existing cases. Exactly one true flag selects its term; both or neither produce ambiguous. Return term and scaled rate.
rate=events/population×scale; new only→incidence; existing only→prevalence Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.
| Output field | Meaning | Value type |
|---|---|---|
| recommendedTerm | Recommended epidemiological term | string; one of "incidence", "prevalence", "ambiguous" |
| calculatedRate | Calculated rate | number; minimum: 0 |
{
"input": {
"countsNewEvents": true,
"countsExistingCases": false,
"events": 50,
"population": 10000,
"scale": 100000
},
"output": {
"recommendedTerm": "incidence",
"calculatedRate": 500
}
}Limitations and assumptions
Fractional counts are accepted. No epidemiological case definition, population quality or person-time incidence model is validated.
Numeric inputs must be finite. Follow the calculation-specific rules for overflow, underflow and exceptional cases. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors.
Alternative or Complementary methods
Use Per-Capita Rate: Calculate a scaled per-capita rate and people-per-event ratio. For a complementary task, use Election Reporting Coverage: Audit election-reporting topic and source-count coverage.
References
-
Rate-Term Selector — tool.io
Similar or alternative tools
- Per-Capita Rate
Calculate a scaled per-capita rate and people-per-event ratio.
- Election Reporting Coverage
Audit election-reporting topic and source-count coverage.