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30-Day Hospital Readmission Rate Benchmark

Scenario

Federal health authorities track unplanned 30-day hospital readmissions. Clinical analysts use CTEs to measure what fraction of discharged patients were readmitted to the facility within 30 days.

Task
Using a CTE, find all patients in `admissions_record` who were discharged and subsequently readmitted within 30 days. Calculate: 1. `total_discharges`: Count of all discharge events 2. `readmissions_within_30d`: Count of readmissions occurring within 30 days of previous discharge 3. `readmission_rate_pct`: `ROUND(100.0 * readmissions_within_30d / total_discharges, 2)` Return these three values in a single summary row.
Expected Output Format

Single row summary showing total discharges, readmissions within 30 days, and readmission rate percentage.

Input Tables & Sample Data0 tables
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About the “30-Day Hospital Readmission Rate Benchmark” SQL Problem

Business Scenario

Federal health authorities track unplanned 30-day hospital readmissions. Clinical analysts use CTEs to measure what fraction of discharged patients were readmitted to the facility within 30 days.

Expected Output & Criteria

Single row summary showing total discharges, readmissions within 30 days, and readmission rate percentage.

Database Table Schema (PostgreSQL DDL)

PostgreSQL 16 WASM

This challenge executes directly against the following relational schema in your browser:

CREATE TABLE admissions_record (
        stay_id INT PRIMARY KEY,
        patient_id INT NOT NULL,
        admission_date DATE NOT NULL,
        discharge_date DATE NOT NULL
      );

Target SQL Clauses & Operators

WITHCOUNTROUND

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