OBJECTIVE: To identify and validate previously established phenotypes of knee osteoarthritis (OA) based on similarities in clinical patient characteristics.
METHODS: Knee OA patients (N = 551) from the Amsterdam OA (AMS-OA) cohort provided data. Four clinical patient characteristics were assessed: upper leg muscle strength, body mass index (BMI), radiographic severity (Kellgren/Lawrence [KL] grade), and depressive mood (the Hospital Anxiety and Depression Scale [HADS] questionnaire). Cluster analysis was performed to identify the optimal number of phenotypes. Differences in clinical characteristics between the phenotypes were analyzed with ANOVA.
RESULTS: Cluster analysis identified five phenotypes of knee OA patients: "minimal joint disease phenotype", "strong muscle strength phenotype", "severe radiographic OA phenotype", "obese phenotype", and "depressive mood phenotype".
CONCLUSIONS: Among patients with knee OA, five phenotypes were identified based on four clinical characteristics. To a high degree, the results are a replication of earlier findings in the OA Initiative, indicating that these five phenotypes seem a stable, valid, and clinically relevant finding.
- Body Mass Index
- Cluster Analysis
- Cohort Studies
- Cross-Sectional Studies
- Knee Joint/diagnostic imaging
- Middle Aged
- Muscle Strength/physiology
- Osteoarthritis, Knee/classification
- Reproducibility of Results
- Severity of Illness Index
- Surveys and Questionnaires