Identifying tinnitus subgroups with cluster analysis.

PURPOSE We believe it is important to uncover tinnitus subgroups to identify subsets of patients most likely to benefit from different treatments. We review strategies for subgrouping based on etiology, subjective reports, the audiogram, psychoacoustics, imaging, and cluster analysis. METHOD Preliminary results of a 2-step cluster analysis based on 246 participants from whom we had 26 categorical and 25 continuous variables were determined. RESULTS A 4-cluster solution suggested the following subgroups: (a) constant distressing tinnitus, (b) varying tinnitus that is worse in noise, (c) tinnitus patients who are copers and whose tinnitus is not influenced by touch (somatic modulation), and (d) tinnitus patients who are copers but whose tinnitus is worse in quiet environments. CONCLUSIONS Subgroups of tinnitus patients can be identified by using statistical approaches. The subgroups we identify here represent a preliminary attempt at identifying such patients. One next step would be to explore clinical trials of tinnitus treatments based on subgroup analyses or on using subgroups in the selection criteria.