External validation of SNOMED-based mental health phenotypes, and their patterns of clinical presentation in the context of the COVID-19 pandemic. UKLLC 00035

Our project aims to understand how visits to primary care for mental health issues, like depression and anxiety, changed over time due to the COVID-19 pandemic. To do this, we will first improve how we identify mental health conditions in medical records.

We will use SNOMED CT—a detailed dictionary of clinical codes for various diseases, symptoms, and treatments. We have created lists of these codes specifically for mental health diagnoses. As part of the project, we will first check how well these code lists (called “phenotypes”) reflect real diagnoses by comparing them to other verified sources (cohort data). This will allow us to improve our phenotypes to better capture mental health records in primary care.

Once our phenotypes are completed, we will examine how primary care visits for mental health have evolved over time, comparing the period before, during, and after the pandemic. To strengthen our findings, we will use data from all available primary care records, not just a specific group of people (specific cohort data).