Kicking Off 2025 Phenotype Phebruary!
Dear OHDSI Community,
We are beyond excited to launch 2025 Phenotype Phebruary! For the past three years, February has been one of the most thrilling times for our community—a month where we come together to focus on the crucial science of phenotype development and evaluation.
Looking back, the past three Phebruaries have brought remarkable achievements:
Dozens of new phenotypes added to our library
Over 50 new collaborators joining our mission
Two peer-reviewed publications advancing the field
Key clinical insights into critical health conditions
Tens of educational sessions and engaging community calls ️
A deeper understanding of the challenges and opportunities in phenotype science
Now, as we step into February 2025, we’re fueled by our past successes, inspired by the magic of OHDSI, and more motivated than ever to push boundaries. We recognize the challenges ahead, but we also believe that the sky is the limit when this incredible community comes together!
Let’s make 2025 Phenotype Phebruary our best one yet! 
Building on the momentum from Dry January, we are excited to continue our journey of tackling the 14 critical evidence gaps—questions where our observational data can provide valuable insights! Addressing these questions starts with building high-quality phenotypes for the exposures, indications (patient populations), and outcomes specified in each research question. Our primary goal this Phebruary is to develop these phenotypes, make them analysis-ready, and ensure they are available in the OHDSI Phenotype Library for future reuse.
How We’ll Achieve This 
We’ll structure the month by aligning each week with a key step in the phenotype development and evaluation process:
Week 1 – Writing clinical descriptions & reviewing prior work
Week 2 – Developing cohort definitions
Week 3 – Evaluating cohorts using CohortDiagnostics
Week 4 – Iterating on cohort definitions & evaluating with additional OHDSI tools
Rather than discussing these steps in the abstract, we will work hands-on using real phenotypes needed for the 14 studies, engaging both study leads and the broader OHDSI community to collaborate at each stage.
Get Involved! 
Weekly instructions will be posted in the forums
Discussions will take place in our community calls
Support will be available in Phenotype WG weekly meetings
Our collective mission is to track our progress and finalize as many phenotypes as possible for these studies, ensuring they are ready for analysis and available in the OHDSI Phenotype Library for broader community use.
Together, let’s make 2025 Phenotype Phebruary a milestone for phenotype development!
Your fellow Phebruarians
@Azza_Shoaibi @aostropolets @Gowtham_Rao
(Thank you to our artificial intelligence friend for the cheese writing style)