Development and validation of the dizziness symptoms questionnaire in Thai-outpatients

“Dizziness” is a common complaint in clinical practice that can occur with anyone. However, since the symptom is caused by a wide range of disorders, a general clinician usually faces some difficulty to detect the cause.

Objective

This study aimed to formulate and validate a simple instrument that can be used to screen and predict the most likely cause of dizziness in Thai outpatients.

Methods

This study was divided into two phases. Phase I included 41 patients diagnosed with common causes of dizziness to determine the algorithm and construct the “structural algorithm questionnaire version 1”. In addition, to test and retest its content validity and reliability until the instrument had an acceptable level of both. Phase II of the study pertained to evaluating its accuracy in clinical trials, 150 patients with dizziness had a face-to-face interview while they were waiting for their medical appointment.

Results

The degree of agreement between the algorithm results and clinical diagnoses was within an acceptable level (κ = 0.69). Therefore, this algorithm was used to construct the structural algorithm questionnaire version 1. The content validity of the structural algorithm questionnaire version 1 evaluated by seven experts. The content validity index values of the questionnaire ranged from 0.71 to 1.0. The Cohen’s kappa coefficient (κ) of intra-rater reliability of the structural algorithm questionnaire version 1 was 0.71. In clinical trials, 150 patients with dizziness had a face-to-face interview while they were waiting for their appointment. The overall agreement between their questionnaire responses and final diagnoses by specialists showed a moderate degree of clinical accuracy (κ = 0.55).

Conclusions

The structural algorithm questionnaire version 1 had a well-developed design and acceptable quality pertaining to both validity and reliability. It might be used to differentiate the cause of dizziness between vestibular and non-vestibular disorders, especially of outpatients with dizziness symptoms.

Keywords
Dizziness; Vestibular symptoms; Questionnaires

Item	Details	Answer
Q1	Episodic attack	□ Yes	□ No
Q2	Single attack	□ Yes	□ No
Q3	Chronic dizziness	□ Yes	□ No
Q4	Triggered by specific head movement: lying down, rolling over, bending over, looking up	□ Yes	□ No
Q5	Triggered by changing to an upright position: lying-to-sitting, sitting-to-standing	□ Yes	□ No
Q6	Triggered by non-specific or all positions of head movements	□ Yes	□ No
Q7	Triggered by pressure change: e.g., cough-sneeze, heavy lifting, Valsava, fast elevators, airplanes, scuba diving, loud sounds	□ Yes	□ No
Q8	Occurred after the trauma onset	□ Yes	□ No
Q9	Occurred after a change in medication: antibiotics, drugs for hypertension, diabetes mellitus, dyslipidemia, arrhythmia, anticonvulsants	□ Yes	□ No
Q10	Occurred after infection onset: fever, headache, ear pain	□ Yes	□ No
Q11	Blackouts or fainting when dizzy	□ Yes	□ No
Q12	Associated with neurologic symptoms	□ Yes	□ No
Q13	Associated with otologic symptoms: hearing loss, tinnitus, ear fullness	□ Yes	□ No
Q14	Associated with fluctuations in hearing loss, tinnitus, ear fullness	□ Yes	□ No
Q15	Associated with sudden unilateral hearing loss	□ Yes	□ No
Q16	Associated with progressive unilateral hearing loss	□ Yes	□ No
Q17	Associated with cervical problems: neck pain, limited movements, arthritis	□ Yes	□ No
Q18	Associated with migraine symptoms	□ Yes	□ No
Q19	Associated with cardiovascular symptoms	□ Yes	□ No
Q20	Associated with stress, anxiety, or certain situations	□ Yes	□ No

Characteristics and diagnoses	Total
A) Characteristic
Age, mean ± SD (years)	52.4 ± 10.2
Gender, n (%)
Male	45 (30.0)
Female	105 (70.0)
Education, n (%)
Primary school or lower	16 (10.7)
High school	16 (10.7)
Diploma	18 (12.0)
Bachelor’s degree	67 (44.7)
Master’s degree or higher	32 (21.3)
Other	1 (0.7)
Duration between visits, mean ± SD (days)	24.8 ± 12.9
B) Diagnostic categories, n (%)
BPPV	39 (26.0)
MD	14 (9.3)
VM	23 (15.3)
Acute unilateral vestibulopathy	2 (1.3)
Other vestibular	28 (18.7)
Non-vestibular	31 (20.7)
Inconclusive	13 (8.7)

Second visit results (n)	First visit results (n)
	BPPV	MD	VM	Acute unilateral vestibulopathy	Other vestibular	Non-vestibular disorders	Total
BPPV	26	1	1	0	0	3	31
MD	0	7	2	0	0	0	9
VM	0	2	19	0	3	2	26
Acute unilateral vestibulopathy	0	0	0	2	0	0	2
Other vestibular	0	2	1	0	11	4	18
Non-vestibular disorders	1	1	1	0	3	29	35
Total	27	13	24	2	17	38	121

Questionnaire results (n)	Clinical diagnosis (n)
	BPPV	MD	VM	Acute unilateral vestibulopathy	Other vestibular	Non-vestibular disorders	Total
BPPV	36	0	0	0	2	1	39
MD	1	5	1	0	5	1	13
VM	1	3	17	0	3	3	27
Acute unilateral vestibulopathy	0	0	0	1	0	1	2
Other vestibular	0	3	2	1	7	3	16
Non-vestibular disorders	1	3	3	0	11	22	40
Total	39	14	23	2	28	31	137

Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Sede da Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico Facial, Av. Indianópolia, 1287, 04063-002 São Paulo/SP Brasil, Tel.: (0xx11) 5053-7500, Fax: (0xx11) 5053-7512 - São Paulo - SP - Brazil
E-mail: revista@aborlccf.org.br

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[1] * Corresponding author. pomuraiwan67@gmail.com (U. Chatchawan).