2,163,535 items of data are available, covering 440,153 participants.
Array indices run from 0 to 54.
- There are 11775 distinct values.
- Mean = 2011-02-01
This field provides, for each participant, the dates when each of the main procedures in Field 41200
was first recorded in the participant's hospital inpatient records. The date can be linked to Field 41200
by using the array structure.
Please note that we have opted to populate this data-field with the episode start date (EPISTART in the HESIN table) or, if that was missing, the admission start date (ADMIDATE in the HESIN table) rather than use the operation date (OPDATE in the HESIN_OPER table). The rationale for this was:
- around 1 in 5 primary procedures lacked a corresponding value for OPDATE in HESIN_OPER;
- some recorded OPDATEs were inconsistent with the other date fields such as EPISTART, ADMIDATE, EPIEND and DISDATE (most likely due to data entry errors);
- for those episodes with a value for OPDATE recorded the majority were the same as the value of EPISTART, with around 99% of OPDATE values within 7 days of the value of EPISTART;
- values of EPISTART/ADMIDATE are more complete and thus may provide greater consistency across data providers.
See the Operations tab of the Hospital Inpatient Data Dictionary (Resource 141140) for further information about these fields.