Guided Notes

Data Quality & Validation

The dimensions of data quality, automated checks in SQL (completeness, validity, uniqueness, timeliness, consistency), reconciliation to source systems and documenting data issues.

Data quality dimensions

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DimensionQuestionExample check
CompletenessIs required data present?% encounters missing a discharge date
ValidityAre values allowed and plausible?Ages 0–120; valid ICD-10 format
UniquenessAre there duplicates?Encounter IDs appearing twice
ConsistencyDo related fields agree?Discharge after admit; sex-specific codes
TimelinessIs data current?Last load date = yesterday
AccuracyDoes it match reality?Chart audit sample