Given a dataset of member claims, write a SQL query to find the top three most expensive medical procedures by region.
Use non-null, non-negative allowed claim amounts and return exactly three procedures per region when available.
Output
- One row per region and procedure, with
region_name, procedure_name, total_claim_cost, and procedure_rank.
- Include the three highest-cost procedures within each region, ordered by total cost descending and procedure name ascending for ties.
- Sort the final results by
region_name, then procedure_rank.
