Dataford
Interview QuestionsInterview GuidesExperiencesMock InterviewsPricing
Get started

Top Treatment Response Patients

EasySQL · PostgreSQL00:00
Practice interviewer
In session
5 left
00:00

Your question is Top Treatment Response Patients. Start with the requirements and the two tables on the right.

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

You need to log in / sign up to run or submit.

Problem

Dana-Farber Cancer Institute researchers need a ranked view of patients with the strongest treatment responses in a clinical trial. Write a PostgreSQL query that calculates each enrolled patient's average finalized response score and returns the top 10 patients.

Requirements

  1. Join patients with treatment_responses using patient_id.
  2. Include only patients whose enrollment_status is Enrolled, finalized assessments, and non-null response scores.
  3. Calculate the average response score and number of qualifying assessments per patient.
  4. Return the 10 highest average scores, breaking ties by the smaller patient_id.

Schema

patients
ColumnTypeDescription
patient_idPKINTUnique patient identifier
patient_nameVARCHAR(100)Patient display name
trial_armVARCHAR(20)Assigned treatment arm
enrollment_statusVARCHAR(20)Current trial enrollment status
treatment_responses
ColumnTypeDescription
response_idPKINTUnique response assessment identifier
patient_idINTReferences patients.patient_id
assessment_dateDATEDate of the response assessment
response_scoreNUMERIC(5,2)Treatment response score
assessment_statusVARCHAR(20)Assessment workflow status
Tablespatientstreatment_responses
Your solutionPostgreSQL
You need to log in / sign up to run or submit.
Run a query to see results