SQL Readmission Rate | Dataford Interview Questions

Children's Hospital of Philadelphia uses discharge data to monitor readmissions. Write a PostgreSQL query that calculates the percentage of discharged admission episodes followed by a subsequent admission within 30 days.

Assume next_admission_date contains the next known admission date for the patient. Count an admission occurring exactly 30 days after discharge as a readmission. Exclude records without a discharge date from the denominator.

Requirements

Return one row with the readmission rate as readmission_rate_pct, rounded to two decimal places.
Use discharged admission episodes as the denominator and include only subsequent admissions from the discharge date through 30 days afterward.

Schema

admissions

Column	Type	Description
admission_idPK	INT	Unique admission identifier
patient_id	INT	Patient identifier
discharge_date	DATE	Date the admission ended
next_admission_date	DATE	Next known admission date for the patient

Your question is SQL Readmission Rate. Start with the requirements and the one table in the Question tab.

Run and submit as often as you like. When you're ready, talk me through your approach or go straight to the code.

Problem

Requirements

Return one row with the readmission rate as readmission_rate_pct, rounded to two decimal places.
Use discharged admission episodes as the denominator and include only subsequent admissions from the discharge date through 30 days afterward.

Schema

admissions

Column	Type	Description
admission_idPK	INT	Unique admission identifier
patient_id	INT	Patient identifier
discharge_date	DATE	Date the admission ended
next_admission_date	DATE	Next known admission date for the patient

Your question is SQL Readmission Rate. Start with the requirements and the one table in the Question tab.

Run and submit as often as you like. When you're ready, talk me through your approach or go straight to the code.