The majority of identified questionnaires were found through our database search. The PubMed and Embase.com searches resulted in a total of 16,370 records. After removal of duplicates, 13,345 unique records remained. In 10,670 cases, screening of the title and abstract was sufficient for record exclusion. However, the screening phase was primarily aimed at identifying potentially relevant questionnaires. Two records were added through expert recommendation.
Full-text examination was performed if the use of a questionnaire could not be excluded on the basis of title and abstract. A total of 2715 articles were fully assessed. At this stage, exclusion of records (Fig.
1 “records excluded [1] and[ 2]”) was primarily because both the abstract and full-text publication of the article were not accessible, full-text language was not English, the study was off-topic (e.g., not in the field of otology, pediatric population), or because of the absence of a questionnaire.
Full-text examination resulted in the exclusion of many “anonymous” questionnaires. These concerned questionnaires without a name, in the absence of a graphic representation, and without any information on the development and/or validation or reference to a corresponding article. Only records without a potentially eligible questionnaire were excluded. Two thousand three hundred forty-three records were excluded based on full-text examination out of the 2715 records. In total, 420 questionnaires were identified as potentially eligible.
In the following phase, all 420 questionnaires were assessed for eligibility. From this point, data on all questionnaires were saved in a separate digital database including the reasons for questionnaire exclusion (Fig.
1: “records excluded [3] and [4]”). Eligibility was assessed by examination of the development and/or validation article. A total of 265 questionnaires were excluded for various reasons (Table
2), and the most common reason being that full text of the development and/or validation article could not be retrieved (
N = 65). Excluded questionnaires were categorized according to symptoms. The remaining 155 questionnaires were included. One hundred forty-nine studies were included in our analyses, because several studies presented more than one questionnaire. The questionnaires were categorized based on the primary symptom of interest. This resulted in the following classification: 33 tinnitus questionnaires, 23 vertigo questionnaires, 84 hearing loss questionnaires, and 15 multiple complaint questionnaires (i.e., ≥3 symptoms of interest). Within these symptom categories, a subdivision was made based on the target population of the different questionnaires (Table
3). The majority of identified hearing loss questionnaires were designed for patients with sensorineural hearing loss using hearing aids or cochlear implants. Questionnaires for patients with autophony, hyperacusis, and patulous Eustachian tube completed this category. Thirty-three questionnaires have been designed for tinnitus sufferers. Unlike hearing loss questionnaires, tinnitus questionnaires do not pertain to specific patient groups, e.g., vestibular schwannoma or Meniere’s disease patients. Questionnaires specific for vestibular schwannoma or Meniere’s disease patients do exist. However, these questionnaires, together with symptom-specific questionnaires on otitis media, Eustachian tube dysfunction, and superior canal dehiscence, were categorized as multiple complaint questionnaires. Other multiple complaint questionnaires focused on dizziness, or cochlear implantees, or were designed as generic otology questionnaires. Most vertigo questionnaires did not relate to a specific condition. However, disease-specific questionnaires for benign paroxysmal positional vertigo, visual vertigo, persistent postural-positional vertigo, motion sickness, and simulator sickness were also identified. An overview of all included questionnaires is presented together with the first author name, year of publication, institution and country of development, a description of the construct assessed by the questionnaire, demographics of the study population of the development/validation study, methods of item generation, and the existing validated translations (Additional files
4,
5,
6 and
7). However, the following conclusions can be drawn from the data as reported in the Additional files
4,
5,
6 and
7. First, in every symptom category, more questionnaires have been developed in the last 20 years than prior to this period: tinnitus (23 out of 33 were developed between 2000 and 2020), vertigo (13 out of 23), hearing loss (50 out of 84), and multiple complaints (13 out of 14). Long questionnaires (<60 items) are no longer conventional. In general, newly developed questionnaires are shorter (<40 items) and many existing questionnaires have been shortened. Furthermore, existing questionnaires are often used in the development of new questionnaires. Some questionnaires are composed out of items from various existing questionnaires, and sometimes a new questionnaire is generated by replacing a single word (i.e., the construct of interest) in every item of an existing questionnaire.
Table 2
Numbers of studies excluded per diagnostic group and reasons for exclusion. Each column represents a different symptom category
No development/validation paper | 13 | 15 | 34 | 3 | - | - |
Open-ended question(s) | 7 | 2 | 25 | - | - | - |
Q not self-administered | 1 | 3 | 3 | 1 | - | - |
No description of development/validation in OA | 4 | 6 | 19 | 3 | 3 | 1 |
No definitive Q presented | 1 | - | - | - | - | - |
Off-topic | 1 | 11 | 15 | 2 | - | - |
No English translation | 3 | 2 | 3 | - | - | - |
No Q availability | 1 | 6 | 12 | 1 | - | - |
Pediatric Q | - | - | 8 | 5 | - | - |
Not a Q | 1 | 3 | 8 | - | - | - |
1-item Q | 3 | 3 | 1 | - | - | - |
Double Q | 9 | 10 | 11 | - | - | - |
Semi-structured Q | - | - | 2 | - | - | - |
Total (n = 265) | 44 | 61 | 141 | 15 | 3 | 1 |
Table 3
The selected 155 questionnaires subdivided per symptom category
Non-specified tinnitus (n=33) | Non-specified vertigo (n=14) | Hyperacusis (n=4) | Meniere’s disease (n=3) |
| Simulator sickness (n=2) | Hearing impaired (n=32) | Otitis media (n=3) |
| Motion sickness (n=2) | Hearing aid users (n=16) | Vestibular schwannoma (n=1) |
| Benign paroxismal positional vertigo (n=3) | Cochlear implant users (n=11) | Eustachian tube dysfunction (n=1) |
| Persistent postural-positional vertigo (n=1) | Geriatric population/older adults (n=2) | General otology population (n=2) |
| Visual vertigo (n=1) | Autophony (n=2) | Superior canal dehiscence (n=1) |
| | Hearing aid candidates (n=4) | Dizziness sufferers (n=1) |
| | General population (n=12) | General population (n=2) |
| | Otology patient, not further defined (n=1) | Cochlear implant users (n=1) |
| | Patulous Eustachian tube (n=1) | |