Predictors for benign paroxysmal positional vertigo with positive Dix–Hallpike test

Figures & data

Table 1 Characteristics of the subjects (derivation and validation sets)

	Derivation set (N = 145)	Validation set (N = 61)
Mean age, y ± SD	45.9 ± 17.4	48.7 ± 17.1
Male, n (%)	49 (33.8)	25(41)
Final diagnosis, n (%)a
Peripheral disease	47 (32)	24 (39)
DHT+ BPPV	12 (8.3)	6 (10)
Mean age, y ± SD	57.0 ± 17.6	54.7 ± 16.3
Male	6 (50)b	1 (17)b
DHT− BPPV	30 (20.7)	14 (23)
Meniere’s disease	3 (2.1)	1 (1.6)
Vestibular neuritis	2 (1.4)	3 (4.9)
Psychogenic disorders	56 (39)	18 (30)
Depressive disorder	24 (17)	5 (8.2)
Somatoform disorder	12 (8.3)	1 (1.6)
Adjustment disorder	6 (4.1)	5 (8.2)
Panic disorder	5 (3.4)	2 (3.3)
Anxiety disorder	3 (2.1)	3 (4.9)
Hypochondriasis	2 (1.4)	1 (1.6)
Othersc	4 (2.8)	1 (1.6)
Central diseases	8 (5.5)	3 (4.9)
Migraine	3 (2.1)	1 (1.6)
Transient ischemic attack		2 (3.3)
Othersd	5 (3.4)
Others	19 (13)	9 (15)
Orthostatic hypotension	5 (3.4)	1 (1.6)
Combined sensory disorder	3 (2.1)	1 (1.6)
Arrhythmia	2 (1.4)
Anemia	2 (1.4)
Drug-induced	2 (1.4)
Cervical vertigo	2 (1.4)
Overwork	2 (1.4)	1 (1.6)
Otherse	1 (0.7)	6 (9.8)
Unknown diagnosis	15 (10)	8 (13)
Patients requiring consultation with specialists, n (%)	56 (39)	15 (25)

Notes: The derivation set is a group used for development of the predictive model, and the validation set is a group used for validation of the model.

a Percentage of patients in each set; the total exceeds 100% because a patient had multiple diseases;

b percentage of DHT+ BPPV patients in each set;

c “others” includes the following diseases (n): conversion disorder (1), paranoia (1), acute stress disorder (1), and factitious disorder (1) in the derivation set; phobia (1) in the validation set;

d “others” includes the following diseases (n): cerebral infarction (1), acoustic neuroma (1), epilepsy (1), Adie’s syndrome (1), and alcoholic cerebellar ataxia (1) in the derivation set;

e “others” includes the following diseases: vasovagal reflex (1) in the derivation set; vasovagal reflex (1), sleep apnea syndrome (1), sleep deprivation (1), cytomegalovirus infection (1), dehydration (1) and deconditioning (1) in the validation set.

Abbreviations: SD, standard deviation; BPPV, benign paroxysmal positional vertigo; DHT+, positive Dix–Hallpike test; DHT−, negative Dix–Hallpike test.

Table 2 Performance characteristics of individual items

	Sensitivity (95% CI)	Specificity (95% CI)	Positive likelihood ratio (95% CI)	Negative likelihood ratio (95% CI)
Temporal factors
Sudden onset	0.92 (0.76–1.00)	0.33 (0.25–0.41)	1.36 (1.33–1.39)	0.26 (0.04–1.59)
Recurrence	0.83 (0.62–1.00)	0.29 (0.21–0.37)	1.18 (1.13–1.22)	0.57 (0.24–1.34)
Diurnal fluctuation	0.67 (0.40–0.93)	0.50 (0.41–0.59)	1.33 (1.21–1.47)	0.67 (0.47–0.94)
Duration of dizziness ≤15 seconds	0.42 (0.14–0.70)	0.84 (0.78–0.90)	2.64 (1.94–3.59)	0.69 (0.61–0.78)
Features
Spinning sensation (rotation)	0.92 (0.76–1.00)	0.65 (0.57–0.73)	2.63 (2.52–2.74)	0.13 (0.02–0.78)
Triggers
Onset when turning over in bed	0.75 (0.51–1.00)	0.77 (0.69–0.84)	3.23 (2.90–3.58)	0.33 (0.20–0.53)
Onset when standing up	0.75 (0.51–1.00)	0.52 (0.44–0.61)	1.57 (1.46–1.69)	0.48 (0.29–0.79)
Onset when looking up	0.42 (0.14–0.70)	0.77 (0.70–0.85)	1.84 (1.39–2.44)	0.75 (0.67–0.85)
Onset when looking down	0.50 (0.22–0.78)	0.71 (0.63–0.79)	1.73 (1.41–2.11)	0.70 (0.59–0.83)
Accessory symptoms
Deafness	0.08 (0–0.24)	0.95 (0.92–0.99)	1.82 (0.22–14.98)	0.96 (0.95–0.98)
Nausea and/or vomiting	0.67 (0.40–0.93)	0.60 (0.51–0.68)	1.65 (1.49–1.83)	0.56 (0.40–0.78)
Double vision	0.08 (0–0.24)	0.94 (0.90–0.98)	1.35 (0.18–10.28)	0.98 (0.96–0.99)
Faintness	0.25 (0.01–0.50)	0.82 (0.76–0.89)	1.40 (0.80–2.45)	0.91 (0.86–0.97)
General factors
History of diabetes mellitus	0.08 (0–0.24)	0.98 (0.95–1.00)	3.69 (0.32–42.19)	0.94 (0.92–0.95)
Loss of enjoyment	0.83 (0.62–1.00)	0.35 (0.27–0.43)	1.28 (1.23–1.33)	0.48 (0.20–1.11)

Abbreviation: CI, confidence interval.

Table 3 Results of binomial logistic regression analysis

Variable	Regression coefficient	Significant probability	Odds ratio (95% CI)	Point*
Duration of dizziness ≤15 seconds	1.47	0.028	4.36 (1.18–16.19)	1
Onset when turning over in bed	2.32	0.001	10.17 (2.49–41.63)	2
Constant	−4.05	<0.001

Notes: Model chi-square test, P < 0.01. Predictive value = 91.0%.

* Calculated based on regression coefficients.

Abbreviation: CI, confidence interval.

Table 4 Performance of the BPPV prediction model

	Number of appropriate items (prediction score)
	0	1	2	3
Derivation set (N = 141), n (%)
DHT + BPPV	1 (1)	2 (8)	4 (15)	5 (42)
Others*	75 (99)	24 (92)	23 (85)	7 (58)
Validation set (N = 61), n (%)
DHT + BPPV	1 (3)	0 (0)	2 (13)	3 (38)
Others*	30 (97)	7 (100)	13 (87)	5 (63)

Notes: With a threshold of 0.5, the positive predictive value (PPV) and negative predictive value (NPV) for the derivation set were 16.9% and 98.7%, respectively, and those for the validation set were 16.7% and 96.8%, respectively. With a threshold of 1.5, PPV and NPV for the derivation set were 23.1% and 97.1%, respectively, and those for the validation set were 21.7% and 97.4%, respectively. With a threshold of 2.5, PPV and NPV for the derivation set were 41.7% and 94.6%, respectively, and those for the validation set were 37.5% and 94.3%, respectively.

* Others include DHT − BPPV and non-BPPV.

Abbreviations: BPPV, benign paroxysmal positional vertigo; DHT+, positive Dix– Hallpike test; DHT−, negative Dix–Hallpike test.

Table 5 Performance characteristics of the two predictive items* for DHT + BPPV in the combined derivation and validation sets

	Sensitivity	Specificity	LR
Positivity of both	0.44 (0.21–0.67)	0.93 (0.90–0.97)	6.81 (5.11–9.10)
Positivity of only one	0.44 (0.21–0.67)	0.64 (0.57–0.71)	1.22 (1.05–1.43)
Positivity of none	0.11 (0–0.26)	0.43 (0.36–0.50)	0.19 (0.08–0.47)

* Note: These are “duration of dizziness ≤15 seconds” and “onset when turning over in bed.”

Abbreviations: BPPV, benign paroxysmal positional vertigo; DHT+, positive Dix– Hallpike test; LR, likelihood ratio.