Rules for Backfill 2007/2008



Note: This page is from an older version of the Data Dictionary and may therefore contain information that is now out of date. It is included here for reference only.

INTRODUCTION

1. Where a provider's data is missing from a freeze (a snapshot of a database), under certain circumstances the missing data can be copied from previous returns to provide a more accurate picture of the data for analysis. This process is called backfilling.

2. Backfill is usually only used for National level enquiries where the missing provider returns could be of large enough significance to corrupt the analysis result.

RULES FOR BACKFILL

3. The following rules apply to the backfill process:

  1. Backfill is only used on F01, F04 and F05 returns.

  2. It is only used when the return is greater than 80%

  3. The backfill process has a cascading effect as follows:
    • F01 - Missing data is obtained from the previous year's F05 return, or where it is absent from that, it is taken from the F05 return from the year before.
    • F04 - Missing data is sought first from the previous year's F05, then from F04 and then from the F05 return from the year before.
    • F05 - Data is sought first from the current year's F04 and then from the previous year's F05.

Date last modified: 5th January 2009