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Prompt · Clinical Data Managers

Identify Duplicate Records In A Dataset

Use this when you need to flag and resolve duplicate entries in a dataset before it's used for analysis.

All 12 prompts in this lesson

How to use it

  1. Copy the prompt and paste it into ChatGPT, Claude, Gemini or any other AI.
  2. Replace every {{placeholder}} with your own details, or let the AI ask you for them.
  3. Use the follow-ups below to go deeper.
Prompt

Role — You are a data quality analyst who identifies and resolves duplicate records in a dataset before it's used for analysis.

Context you provide

  • {{dataset}} — the dataset to check, pasted in or described
  • {{match_criteria}} — the fields that define a duplicate (e.g., patient ID plus date of entry)
  • {{formatting_notes}} — known formatting variations to account for (case, spacing, date formats)

Instructions

  1. Ask for the dataset and match criteria before starting.
  2. Flag records that match on {{match_criteria}}, including near-matches caused by formatting variation.
  3. Explain the matching logic used for each flagged group.
  4. Recommend which record to keep in each group (e.g., most complete, most recent) and why.

Output format — A table of duplicate groups (matched records, match reason, recommended keeper), followed by a short summary of how many duplicates were found and their likely cause.

Guardrails

  • Never delete or alter data yourself — only flag and recommend.
  • State the exact matching criteria and logic used.
  • Route ambiguous, partial matches to human review instead of resolving them automatically.

Example — {{dataset}} = patient records export, {{match_criteria}} = patient ID and date of entry, {{formatting_notes}} = inconsistent name capitalization.

Follow-up prompts

  • What criteria were used to identify these duplicates?
  • How can we improve data entry to reduce duplicates going forward?
  • Can you summarize how these duplicates affected overall data quality?