Perceived health of patients with common variable immunodeficiency - a cluster analysis

Common variable immunodeficiency (CVID) is a complex disease with various influences on perceived health, which correlate with different outcomes, including new morbidity and mortality. Our hypothesis was that CVID patients fall into distinct clusters of perceived health which can inform care. Ward hierarchical cluster analysis and K-means cluster analysis were performed on data of 209 CVID patients to identify subgroups regarding their self-reported physical and mental health status, assessed by the physical (PCS) and mental component scores (MCS) of the Short Form-12 (SF-12). Four clusters of CVID-patients were identified. Cluster 1 was the largest cluster, characterized by a relatively high physical and mental health status (44·0%). In contrast, cluster 2 (21·1%) included patients with low physical and mental health status. Clusters 3 and 4 were mixed groups with high mental and low physical health (15·8%) and vice versa (19·1%). Significant differences between the clusters were found for patient-reported outcomes such as work ability and health literacy, but not for CVID-associated complications such as enteropathy, interstitial lung disease, granulomatosis, lymphadenopathy and autoimmune cytopenia or laboratory parameters such as immunoglobulin levels or B cell-based classification. The results suggest different subgroups of CVID patients with contrasting individual needs which, surprisingly, did not differ in clinical or laboratory characteristics. The main finding of this study is that patients with CVID fall into four distinct clusters according to perceived health, which are largely independent of CVID complications.