A clinic and a county do not necessarily match
Suppose a hypothetical clinic records 500 visits and the county has 10,000 residents. Dividing 500 by 10,000 gives 5 visits per 100 residents, but that interpretation is incomplete if some visits come from outside the county or some people visit repeatedly.
It is not automatically the percentage of residents served.
Name the unit on both sides
| Numerator | Possible denominator question |
|---|---|
| Unique people served | Which eligible people could have been served? |
| Visits | Which population and time period generated those visits? |
| Households reporting a need | Which households were represented by the sample? |
A person count and a household count are not interchangeable.
Check geography and time together
Population boundaries can change, and an old estimate may not match a recent service period. A rate can shift because the denominator changed rather than because the event count did.
If the appropriate population is uncertain, report that uncertainty or use a more limited descriptive count. A denominator is not a decoration added to make a number look comparable. It defines the question the rate answers, and it should be chosen before interpreting the result.
