Table 4.

Variable importance of the 20 most relevant variables to differentiate between the seven different vestibular diagnoses (functional dizziness, vestibular migraine, Menière's disease, benign paroxysmal positional vertigo, unilateral vestibulopathy, bilateral vestibulopathy, and vestibular paroxysmia).

Variables	Mean decrease in accuracy	Root node#
Vomiting	1.41	744
Age	1.02	978
Hearing problems	0.93	682
Turning in bed as a trigger	0.92	343
Attack duration: <2 min	0.76	1,105
Rotational vertigo	0.67	338
Getting in and out of bed is difficult	0.63	138
Attack duration: hours	0.61	446
Nausea	0.57	481
Positional maneuver as a trigger	0.38	223
Ear pressure	0.29	321
Walking in the dark is difficult	0.27	780
Walking on sidewalks is difficult	0.24	504
Ear noise	0.20	72
Attack duration: several days	0.16	491
Provocational nystagmus	0.16	46
Gait disturbance	0.16	268
Bending over as a trigger	0.16	62
Eye movement disorder	0.14	52
Headache	0.12	31

The estimation of importance measures was based on random forests with 10,000 trees. The mean decrease in accuracy was based on permutation in importance.

^#Root node indicates how often a variable was used to split the root node (higher frequencies indicate higher relevance for the classification).