Suppression rules

In order to address the data disclosure risk inherent in the presentation of small numbers, suppression has been applied to the data used in the DQMI. The first stage of suppression is that all individual data items with a total number of records less than 25 at the organisation level have been excluded from the data, except for when the corresponding coverage value is zero. Further suppression is then applied as detailed below;

APC, OP and ECDS

1. Values between one and 7 replaced with an asterisk.
2. The corresponding percentages for the percentage of Valid and Complete records are suppressed when the suppression takes place in the ‘Number of Records’ or ‘Valid and Complete’ columns.
3. The corresponding percentages for the percentage of Valid and Complete records are recalculated to treat all ‘Excess in Defaults’ as valid (or zero) when the suppression takes place in ‘Defaults’ or ‘Defaults in Excess’ column.
4. When only the ‘Defaults in Excess’ column is suppressed then ‘Defaults’ are replaced with an asterisk.
5. All remaining integer values are rounded to the nearest five.

DID

1. Values between one and two replaced with an asterisk.
2. The corresponding percentages for the percentage of Valid and Complete records are suppressed when the suppression takes place in the ‘Number of Records’ or ‘Valid and Complete’ columns.
3. The corresponding percentages for the percentage of Valid and Complete records are recalculated to treat all ‘Excess in Defaults’ as valid (or zero) when the suppression takes place in ‘Defaults’ or ‘Defaults in Excess’ column.
4. ‘Percentage of valid and complete’ is presented to the nearest whole number.
5. When only the ‘Defaults in Excess’ column is suppressed then ‘Defaults’ are replaced with an asterisk.
6. All remaining integer values are rounded to the nearest five.

CSDS, MHSDS, IAPT and MSDS

1. Values between zero and four replaced with an asterisk.
2. The corresponding percentages for the percentage of Valid and Complete records are suppressed when the suppression takes place in the ‘Number of Records’ or ‘Valid and Complete’ columns.
3. The corresponding percentages for the percentage of Valid and Complete records are recalculated to treat all ‘Excess in Defaults’ as valid (or zero) when the suppression takes place in ‘Defaults’ or ‘Defaults in Excess’ column. Data Quality Maturity Index Copyright © 2021 Health and Social Care Information Centre. NHS Digital is the trading name of the Health and Social Care Information Centre. 12
4. ‘Percentage of valid and complete’ is presented to the nearest whole number.
5. When only the ‘Defaults in Excess’ column is suppressed then ‘Defaults’ are replaced with an asterisk, with the exception for when ‘Defaults in Excess’ is equal to zero.
6. All remaining integer values are rounded to the nearest five.

Suppression rules differ to retain consistency with the standard Statistical reporting for these datasets, available in Appendix 3: Section Links to Information and Reports for Individual Datasets.