Definition of Coverage Rate

The coverage rate measures, for each vaccine/dose (i.e. Penta 2nd dose), the percentage of the target that received the vaccine in the specified time period. For example the if the target for Penta 2 vaccinations is 100 per month, and 90 children received a dose of Penta 2, the coverage rate is 90%.

General Calculation

Doses Administered to 0-11 month olds / Target Group

Target Group:

Each health unit has a target for the number of people to administer each vaccine/dose to. This target is based on the cachement population of the health unit.

From a SELV perspective, the target is determine by the following:

  1. Cachement Population on Manage Facility Screen (this value is initially being set based on the value in vrMIS)
  2. ISA Calculation on Configure Produce ISA Screen

ISA is calculated as {min, max} Population *  Target Population Percentage * Doses per Patient Per Year * Wastage Factor / 12 * Buffer Stock Level + (Adjustment Quantity)

Target group for each vaccine dose is a subset of this calculation, and is defined as:  Population *  Target Population Percentage  / 12

 Doses Administered:

Doses administered for 0-11 month olds at the Health Unit and Mobile Brigade. For example for BCG the calculation would be:

(BCG_HU_0-11 + BCG_MB_0-11 )  

Comments:

For all calculations it is important the numerator and denominator a relating to the same data set. For example for VAT Target Group is calculated only for Pregnant Mothers (Mulheres Gravidas). As such, the numerator should only include doses administered to pregnant mothers:  


(VAT_MG_HU_1 + VAT_MG_MB_1 + VAT_MG_HU_25 + VAT_MG_MB_25) /    VAT Target Group

Records to Include in Calculation

Coverage rate should only be calculated for a facility/vaccine/dose when the following criteria are met:

  1. Target Group IS NOT NULL       AND

  2. Total Vaccinations Administered IS NOT NULL

If these criteria are not met, coverage rate for the facility/vaccine/dose is Null and coverage rate it is excluded from all coverage rate summations by geographic or time dimensions.

Examples:

Target

Group

Doses Administered

0-11 Mos HU

Doses Administered

0-11 Mos MB

Doses Administered

12-23 Mos HU

Doses Administered

12-23 Mos MB

Total Doses

Administered 0-11 mos

Coverage

Rate

Include Target Group in

Coverage Summation Denominator?

100101010102020%Yes
100n/a (null)n/a (null)1n/a (null)nullnullNo
1000n/a (null)n/a (null)n/a(null)00%Yes
100n/a (null)n/a (null)n/a (null)n/a (null)NullNullNo
null*nullnullnullnullNullNullNo
null**1010101040NullNo

*We don't think this situation will ever occur in the data. Target group will always be included in the visit record snapshot when created even if the facility is not visited or not synchronized. 

** Perhaps this scenario could happen if the ISA is not configured for the product? Regardless, if by some quirk Target Group is Null, Coverage Rate should be Null as well.

 

 

Migrating Coverage Rate from vrMIS 

Data migration from vrMIS needs to verify that the following criteria are met: 

  1. If the visit record is generated by SELVData (due to vrMIS data gap), either target group or total doses administered must be null. The record is not included in coverage rate summations.
  2. For visit data migrated directly from vrMIS, check that Total Doses Administered is set to 0 versus Null as appropriate:
    1. Null if all sub-fields are null
    2. 0 if on of the sub-fields is 0