10 Medical Mutual SQL Interview Questions (Updated 2024)
At Medical Mutual of Ohio, SQL is used for analyzing huge volumes of healthcare data, such as patient medical records, claims data, and billing information, for patterns and trends. It is also used for creating robust databases for accurate patient and insurance information storage, including ensuring data privacy and security, the reason why Medical Mutual often asks SQL questions during interviews for Data Science, Analytics, and Data Engineering jobs.
So, to help you study, we've curated 10 Medical Mutual of Ohio SQL interview questions – can you answer each one?
10 Medical Mutual of Ohio SQL Interview Questions
SQL Question 1: Identify Power Users at Medical Mutual
Company "Medical Mutual" wants to identify their power users or VIP users who are most important to the business. These are the users who are frequently requesting big orders, identified by the total cost of requests. Write an SQL query to retrieve the details of the top 5 users who have the highest total cost of requests in the year 2022.
Example Input:
| user_id | username |
|---|---|
| 1 | john89 |
| 2 | claire92 |
| 3 | mark23 |
| 4 | peter49 |
| 5 | sarah87 |
Example Input:
| request_id | user_id | request_date | total_cost |
|---|---|---|---|
| 10456 | 1 | 01/02/2022 | 1000 |
| 10457 | 3 | 02/16/2022 | 4000 |
| 10458 | 2 | 06/07/2022 | 1500 |
| 10459 | 1 | 08/10/2022 | 2000 |
| 10460 | 4 | 03/11/2022 | 1200 |
Answer:
This SQL query first joins the 'users' and 'requests' tables on . It then filters the requests based on their date to only include those made in 2022. This leaves us with users and their cost of requests in 2022. The result is then grouped by and to calculate the total cost for each user. The results are then ordered in a descending manner to get the users with the highest total cost on top, and finally limited to 5 to get the top 5 users.
To work on a similar customer analytics SQL question where you can solve it interactively and have your SQL code automatically checked, try this Walmart Labs SQL Interview Question:
SQL Question 2: Department Salaries
Imagine you had a table of Medical Mutual employee salary data, along with which department they belonged to. Write a query to compare the average salary of employees in each department to the company's average salary for March 2024. Return the comparison result as 'higher', 'lower', or 'same' for each department. Display the department ID, payment month (in MM-YYYY format), and the comparison.
You can solve this problem directly within the browser on DataLemur:
The answer is LONG – 30+ lines of SQL. You can find a detailed solution with hints here: Department vs. Company Salary.
SQL Question 3: What does the constraint do?
A constraint ensures that all values in a column are different. This provides uniqueness for the column(s) and helps identify each row uniquely. Unlike primary key, there can be multiple unique constraints defined per table.
SQL Question 4: Calculating the average cost of medical treatments by specialty
Let's suppose that Medical Mutual has a series of tables that represent the claims made by their subscribers. Each claim represents a medical treatment performed by a provider specialist and has associated cost.
For this question we are interested in two tables:
- : Contains information about the treatment, the specialist who performed it, and the cost of the treatment:
Example Input:
| treatment_id | specialist_id | cost |
|---|---|---|
| 1001 | 123 | 500 |
| 1002 | 345 | 800 |
| 1003 | 123 | 700 |
| 1004 | 345 | 1200 |
| 1005 | 678 | 300 |
- : Contains information about the specialty of each specialist:
Example Input:
| specialist_id | specialty |
|---|---|
| 123 | Cardiology |
| 345 | Orthopedics |
| 678 | Dermatology |
We would like to calculate the average cost of medical treatments by specialty, ordered by cost in descending order. Use an SQL window function in your solution.
Example Output:
| specialty | avg_cost |
|---|---|
| Orthopedics | 1000 |
| Cardiology | 600 |
| Dermatology | 300 |
Answer:
This query calculates the average cost of treatments for each specialty. It does this by joining the table with the table on to get the specialty for each treatment. The window function is used with to compute the average cost of treatments for each specialty. Finally, the result is ordered by in descending order to get the specialties with the highest average treatment cost at the top.
To solve another window function question on DataLemur's free interactive SQL code editor, try this Google SQL Interview Question:
SQL Question 5: Can you explain the concept of a cross-join, and their purpose?
A cross-join, also known as a cartesian join, is a JOIN that produces the cross-product of two tables. In a cross-join, each row from the first table is matched with every row from the second table, resulting in a new table with a row for each possible combination of rows from the two input tables.
Let's say you were building a Machine Learning model that attempts to score the probability of a customer purchasing a Medical Mutual product. Before working in Pandas and Tensorflow, you might want to do some Exploratory Data Analysis (EDA) in SQL, and generate all pairs of customers and Medical Mutual products.
Here's a cross-join query you could run:
Cross-joins are useful for generating all possible combinations, but they can also create huge tables if you're not careful. For instance, if you had 10,000 potential customers and Medical Mutual had 500 different product SKUs, the resulting cross-join would have 5 million rows!
SQL Question 6: Design a Database for Patient Records in a Hospital System
Medical Mutual is a health insurance company that needs to have its patient records organized in a manner that is easy to query. Each patient has a unique patient_id, a name, age, address, and medical history. Medical history includes details about previous diseases, medications taken, and surgeries undergone. Patients are often seen by different doctors, who also need to be tracked in the database. Each doctor has a unique doctor_id, name, specialty, and contact information.
Design a database to store this information and write a query that returns all patient names that have previously been treated for a specific disease, say 'Cancer', sorted by their age.
Example Input:
| patient_id | name | age | address |
|---|---|---|---|
| 2121 | John Doe | 45 | 123 Pine St |
| 3122 | Jane Doe | 50 | 234 Oak Rd |
| 3490 | Bob Smith | 47 | 456 Maple Dr |
Example Input:
| doctor_id | name | specialty | contact_info |
|---|---|---|---|
| 5500 | Dr. White | Oncology | dr.white@medmutual.com |
| 5501 | Dr. Green | Cardiology | dr.green@medmutual.com |
Example Input:
| patient_id | disease | medications | surgeries |
|---|---|---|---|
| 2121 | Cancer | Medication A, Medication B | Surgery A |
| 3122 | Heart Disease | Medication C | Surgery B |
| 3490 | Cancer | Medication D | Surgery C |
Answer:
Here is a sample query based on the table structure provided:
This query first links the patients and medical_history tables on their common attribute, patient_id. It then filters the records for only those with the disease 'Cancer'. Finally, it sorts the resulting patient names by age. However, there would be other considerations while designing the database, such as handling many-to-many relations between doctors and patients, and tracking other attributes such as visit dates, payment records etc.
SQL Question 7: What's the operator do, and can you give an example?
is used to combine the output of multiple statements into one big result!
For a concrete example, say you were a Data Analyst supporting the Sales Analytics team at Medical Mutual, and data on potential sales leads lived in both Salesforce CRM and Hubspot. To write a query to analyze leads created after 2023 started, across both CRMs, you could use in the following way:
SQL Question 8: Filtering Medical Mutual Customer Data
As a data analyst for Medical Mutual, your job is to filter down the customers' database based on multiple conditions. Medical Mutual wants to identify customers who are aged between 30 to 50, live in Ohio, and have been a member for at least 5 years. Can you write a SQL query to filter these customers' data from the main customer database?
Example Input:
| customer_id | first_name | last_name | age | state | membership_years |
|---|---|---|---|---|---|
| 1001 | John | Doe | 34 | OH | 6 |
| 1002 | Sarah | Smith | 27 | OH | 2 |
| 1003 | Bob | Johnson | 45 | OH | 7 |
| 1004 | Alice | White | 52 | TX | 10 |
| 1005 | Charlie | King | 38 | OH | 4 |
Example Output:
| customer_id | first_name | last_name | age | state | membership_years |
|---|---|---|---|---|---|
| 1001 | John | Doe | 34 | OH | 6 |
| 1003 | Bob | Johnson | 45 | OH | 7 |
Answer:
This SQL query filters the table and selects only the fields where the is between 30 and 50, the is OH (Ohio) and is 5 or more. So, the output will only include customers within the age group of 30 to 50, who live in Ohio and have been a member of Medical Mutual for at least 5 years.
SQL Question 9: Calculate the Average Cost per Medical Procedure by Area
Medical Mutual is an insurance company that needs to process and analyze a large amount of data relating to medical procedures. You're tasked to derive insights about the average cost per procedure in each area. Given a table tracking various medical procedures, their cost, and the area where they were performed.
The table has the following schema:
Example Input:
| proc_id | proc_name | area | cost |
|---|---|---|---|
| 1 | MRI Scan | New York | 1200 |
| 2 | CT Scan | Los Angeles | 700 |
| 3 | MRI Scan | Los Angeles | 1300 |
| 4 | CT Scan | New York | 750 |
| 5 | MRI Scan | New York | 1250 |
Your task is to write a SQL query that calculates the average cost of each procedure by area.
The output should consist of the area, procedure name and the average cost in that area.
Example Output:
| area | proc_name | avg_cost |
|---|---|---|
| New York | MRI Scan | 1225.00 |
| Los Angeles | CT Scan | 700.00 |
| Los Angeles | MRI Scan | 1300.00 |
| New York | CT Scan | 750.00 |
Answer:
You can solve this problem using the clause paired with the function like this:
This query groups the procedures by area and procedure name and for each group, the average cost is calculated and returned.
SQL Question 10: Could you explain the differences between an inner and full outer join?
A full outer join returns all rows from both tables, including any unmatched rows, whereas an inner join only returns rows that match the join condition between the two tables.
For a tangible example, suppose you had a table of Medical Mutual orders and Medical Mutual customers.
Here's a SQL inner join using the orders and customers tables:
This query will return rows from the orders and customers tables that have matching values. Only rows with matching values will be included in the results.
Here is an example of a using the orders and customers tables:
This query will return all rows from both the orders and customers tables, including any rows that do not have matching values. Any rows with null values for either table will be included in the results.
How To Prepare for the Medical Mutual SQL Interview
Assuming that you've already got basic SQL skills, the next best tip we have to prepare for the Medical Mutual SQL interview is to solve as many practice SQL interview questions as you can! Beyond just solving the earlier Medical Mutual SQL interview questions, you should also solve the 200+ DataLemur SQL Interview Questions which come from companies like Google, Facebook, Microsoft and Amazon.
Each SQL question has multiple hints, detailed solutions and crucially, there is an online SQL code editor so you can right in the browser run your SQL query and have it graded.
To prep for the Medical Mutual SQL interview you can also be wise to solve SQL problems from other insurance companies like:
- Public Storage SQL questions
- Prologis SQL questions
- Selective Insurance SQL questions
- Stewart Title SQL questions
Keep up with Medical Mutual's latest news and announcements, driving innovation and growth in the healthcare sector!
However, if your SQL skills are weak, don't worry about diving straight into solving questions – go learn SQL with this SQL tutorial for Data Scientists & Analysts.
This tutorial covers things like window functions and filtering data with WHERE – both of these show up routinely in Medical Mutual SQL assessments.
Medical Mutual of Ohio Data Science Interview Tips
What Do Medical Mutual Data Science Interviews Cover?
In addition to SQL interview questions, the other topics to practice for the Medical Mutual Data Science Interview include:
- Probability & Statistics Questions
- Python or R Programming Questions
- Product Data Science Interview Questions
- Machine Learning Questions
- Resume-Based Behavioral Questions
How To Prepare for Medical Mutual Data Science Interviews?
I think the optimal way to study for Medical Mutual Data Science interviews is to read the book I wrote: Ace the Data Science Interview.
It solves 201 data interview questions taken from FAANG, tech startups, and Wall Street. The book's also got a refresher covering Stats, ML, & Data Case Studies. And finally it's vouched for by the data community, which is why it's earned 1000+ reviews on Amazon and a 4.5-star rating.
While the book is more technical in nature, it's also important to prepare for the Medical Mutual behavioral interview. A good place to start is by understanding the company's unique cultural values.