The SSNAP summary report provides the most detailed breakdown of how the SSNAP score is calculated; including how to calculate each key indicator score, the score for each domain and the final SSNAP score. This is found in the Technical Scoring Info tab and the Technical KI Information tab.
National level summary report are available here - Results > Clinical audit > National
Simplified guidance on how each key indicator is calculated can be found on our Simplified Technical Guidance page.
Below is a simplified guide of how the overall SSNAP score is calculated.
Step one: calculating domain scores
Domain scores are typically the average percentage of the key indicators within the domain. However, for some of the key indicators this is not appropriate. For these key indicators, a score is attributed based on the performance of the key indicator. For example:
| 1.2 Percentage of patients scanned within 12 hours of clock start |
| The score for this indicator is allocated depending on the percentage scanned within 12 hours: |
| A score of 100 is obtained if 95% or more of patients are scanned within 12 hours |
| A score of 90 is obtained if 90% to <95% of patients are scanned within 12 hours |
| A score of 80 is obtained if 85% to <90% of patients are scanned within 12 hours |
| A score of 70 is obtained if 80% to <85% of patients are scanned within 12 hours |
| A score of 60 is obtained if 75% to <80% of patients are scanned within 12 hours |
| A score of 50 is obtained if 70% to <75% of patients are scanned within 12 hours |
| A score of 40 is obtained if 65% to <70% of patients are scanned within 12 hours |
| A score of 30 is obtained if 60% to <65% of patients are scanned within 12 hours |
| A score of 20 is obtained if 55% to <60% of patients are scanned within 12 hours |
| A score of 10 is obtained if 50% to <55% of patients are scanned within 12 hours |
| A score of 0 is obtained if less than 50% of patients are scanned within 12 hours |
The domain score is calculated by adding together all the key indicator scores in the domain and dividing by the number of applicable key indicators. Each domain score is then categorised into levels A to E (score for A-E for each domain can be found in the tab for each domain in the Summary Report).
Please note: where a team does not have a particular key indicator score (e.g. teams which do not routinely admit patients would not have a team-centred % scanned within 1 hour score) that key indicator would not count towards the domain score. The domain score would be calculated out of relevant key indicators within the domain.
A patient-centred domain score is calculated from the patient-centred key indicators scores and a team-centred domain score is calculated from the team-centred key indicator scores.
Step two: combining domain scores into Total Key Indicator
Each domain is assigned a number of points based on the domain score.
A=100
B=80
C=60
D=40
E=20
For example:
An average score of 78% for patient-centred Domain 10 would be a level C performance. Level C is worth 60 points towards the patient-centred Total Key Indicator score.
The Total Key Indicator score is calculated by adding together all of the domain points and dividing by the number of applicable domains. This score is assigned a patient-centred Total key Indicator level as below:
A=over 80
B=between 70 and ≤80
C=between 60 and <70
D=between 40 and <60
E=less than 40
A Total Key Indicator score is calculated for the team-centred domains and the patient-centred domains.
Please note: If a domain (patient-centred or team-centred) is wholly not applicable (e.g. the whole of Domain 1 would be not applicable for teams who do not directly admit patients), then the total KI score (patient-centred or team-centred) would be calculated out of the relevant domains.
Teams with no patients eligible for thrombolysis are excluded from team-centred domain 3 scoring.
Step three: Adjusting for case ascertainment and audit compliance
The Combined Total Key Indicator score is created by averaging the patient-centred and team-centred Total key Indicator scores. Low case ascertainment or audit compliance will result in a team receiving an adjustment. The size of the adjustment varies depending on how low the case ascertainment or audit compliance is.
Details on how audit compliance and case ascertainment are calculated can be found here:
Case ascertainment - How is it calculated?
Audit compliance - How is it calculated?
The following adjustments are made:
| Adjustment 1: Case ascertainment |
| Band A = Case ascertainment is 90% or higher, no adjustment is made to the score (100% of the score is maintained) |
| Band B = Case ascertainment is between 80 to <90%, an adjustment resulting in 95% of the score is made |
| Band C = Case ascertainment is between 70 to <80%, an adjustment resulting in 85% of the score is made |
| Band D = Case ascertainment is between 60 to <70%, an adjustment resulting in 70% of the score is made |
| Band E = Case ascertainment is less than 60%, an adjustment resulting in 50% of the score is made |
| Adjustment 2: Audit compliance |
| Band A = Audit compliance is 90 or higher, no adjustment is made to the score (100% of the remaining score following Adjustment 1 is maintained) |
| Band B = Audit compliance is between 80 to <90, an adjustment resulting in 95% of the remaining score following Adjustment 1 is made |
| Band C = Audit compliance is between 70 to <80, an adjustment resulting in 90% of the remaining score following Adjustment 1 is made |
| Band D = Audit compliance is between 50 to <70, an adjustment resulting in 85% of the remaining score following Adjustment 1 is made |
| Band E = Audit compliance is less than 50, an adjustment resulting in 80% of the remaining score following Adjustment 1 is made |
For example:
A team with 70-79% case ascertainment would keep 85% of their original score in Adjustment 1. If that team had 80-89% audit compliance, the team would occur a second adjustment, keeping 95% of their remaining score.
The resulting adjusted SSNAP score is then assigned a level:
A=over 80
B=between 70 and <80
C=between 60 and <70
D=between 40 and <60
E=less than 40
Step four: calculating patient-centred and team-centred SSNAP scores
The same process in step three is used to calculate the patient-centred and team-centred SSNAP scores, except the specific Total Key Indicator scores are used (i.e. patient-centred Total Key Indicator or team-centred Total Key Indicator) rather than the Combined Total Key Indicator score.