Clinical Trial Details
— Status: Completed
Administrative data
| NCT number |
NCT04892095 |
| Other study ID # |
ETS |
| Secondary ID |
|
| Status |
Completed |
| Phase |
|
| First received |
|
| Last updated |
|
| Start date |
June 1, 2017 |
| Est. completion date |
October 30, 2018 |
Study information
| Verified date |
May 2021 |
| Source |
Mario Negri Institute for Pharmacological Research |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Observational
|
Clinical Trial Summary
A European cross-sectional study was conducted with the aims of: i) examining inter-country
differences in prevalence of tinnitus by comparing prevalence estimates in countries with
relatively low versus high gross domestic product (GDP) per capita and comparing prevalence
estimates in countries within different European regions (i.e., Northern, Southern, Eastern
and Western Europe); ii) understanding the effect of sex, age, socio-economic variables, body
mass index (BMI), and marital status on overall prevalence of tinnitus; iii) assessing the
effect of hearing difficulty on tinnitus prevalence; and iv) exploring the effect of tinnitus
severity on use of healthcare resource for tinnitus Overall, approximately 12,000 individuals
aged 18 years or over are enrolled in 12 different European countries (BG, DE, ES, FR, GR,
IE, IT, LV, PL, PT, RO, UK). Survey sample from each country were representative of the
country-specific population in terms of sex, age, and socio-economic characteristics.
Description:
BACKGROUND AND RATIONALE Tinnitus is a common symptom of clinically heterogeneous pathologies
and is defined as the conscious perception of an auditory sensation in the absence of a
corresponding external stimulus. Tinnitus, in its debilitating form, negatively affects
emotional health and social well-being, and can precipitate psychological distress severe
enough to cause self-harm and suicidal ideations, while exerting substantial individual and
societal financial burden. Therefore, it becomes crucial to implement adequate preventive
measures and health interventions. According to population-based studies from Western Europe
and US, tinnitus prevalence lies between 10% and 15%. Nonetheless, there is a lack of clear
understanding of global prevalence of tinnitus. Inherent methodological drawbacks and between
study differences hinder deriving a global estimate by pooling data from studies conducted in
different countries and world regions. Therefore, uncertainties with regards to the
prevalence of tinnitus remain.
OBJECTIVE The primary objective of this population-based cross-sectional study is to estimate
the overall and country specific prevalence of any tinnitus, bothersome tinnitus, and severe
tinnitus in 12 European Union (EU) countries.
The study data have been analyzed to fulfil the following secondary objectives:
- To examine inter-country differences in prevalence of tinnitus by making the following
comparisons:
- Comparing prevalence estimates in countries with relatively low versus high gross
domestic product (GDP) per capita
- Comparing prevalence estimates in countries within different European regions
(i.e., Northern, Southern, Eastern and Western Europe)
- To understand the effect of sex, age, socio-economic variables, body mass index (BMI),
and marital status on overall prevalence of tinnitus
- To assess the effect of hearing difficulty on tinnitus prevalence
- To explore the effect of tinnitus severity on use of healthcare resource for tinnitus
METHODS Study design To achieve the aims of this study, the investigators conducted
face-to-face population-based cross-sectional survey in 12 strategically selected EU28
countries (Bulgaria, England, France, Germany, Greece, Ireland, Italy, Latvia, Poland,
Portugal, Romania, and Spain).
For each country, the study sample is representative of the general population aged 18 years
and above in terms of age, sex, geographic area, and socio-economic characteristics.
Multi-stage methodology was used as the preferred sampling methodology. In the first stage,
the primary unit of selection was geographic area or voting center. In the second stage,
households or municipalities were selected. In the last stage, respondents were chosen
randomly, in order to be representative of the population. Other methods, including
stratified or simple sampling or quota methods, were also accepted wherever it is not
possible to conduct a multistage random sampling.
Selection of countries For the present study, an appropriate sample of 12 European
countries-all EU28 Member States (MS) -representing geographical, legislative and cultural
variations across the EU, have been selected. The selected European countries were as
follows: Bulgaria (BG), England (UK), France(FR), Germany(DE), Greece (GR), Ireland (IE),
Italy (IT), Latvia (LV), Poland (PL), Portugal (PT), Romania (RO), and Spain (ES). These
countries were selected after taking into account several aspects, including: i) different
geographical distribution; ii) different level of per capita income. According to geographic
area, the investigators considered countries from northern (IE, UK), central/western (DE,
FR), central/eastern (BG, LV, PL, RO), and southern Europe (ES, IT, GR, PT). Moreover, the
selection included the 7 most populated EU28 MS (DE, ES, FR, IT, UK, PL, RO), and, among less
populated countries, the investigators prioritized middle-income countries (BG, RO). Overall,
the 12 selected EU MS represent 78.8% of the EU28 overall population.
Study population In each of the 12 selected European countries, approximately 1000
individuals, representative of the general population aged 18 years and above in terms of
age, sex, geographic area, and socio-economic characteristics, were enrolled in this
cross-sectional study. The final sample therefore includes a total of 11,427 subjects.
Sample size computation The sample size for each country allowed us to obtain prevalence
estimates with a maximum standard error (SE) lower than ± 1.6%. Therefore, with such a sample
size the investigators have been able to provide stable prevalence estimates (with a
relatively small 95% confidence interval), both overall and country-specific.
Data collection In each country, individuals were surveyed by trained interviewers through
face-to-face interviews using a structured standardized questionnaire. Data collection was
coordinated by DOXA, a leading market research organization and Italian branch of the
Worldwide Independent Network/Gallup International Association (WIN/GIA), and performed in
collaboration with its European partners. Data was collected within computer assisted
personal interviews (CAPI). The fieldworks lasted two to three months in each country. The
English version of the questionnaire has been developed by collaborators from University of
Nottingham (UK) University of Regensburg (Germany), and Mario Negri Institute (Italy). Before
fieldwork, the tinnitus-related questions were translated from English into various
country-specific languages using the good practice guidelines for questionnaire translation.
The details of the translation process have been published as a technical note.
The country-specific information provided by DOXA and its European partners for each European
country include information on sampling methodology (e.g., sampling method used, response
rate, fieldwork dates, age range). The survey questionnaire is designed to collect
individual-level information for each survey participant, and is divided in two sections. The
first section provided information on: socio-economic and demographic characteristics (e.g.,
sex, age, level of education, and profession). The second section provided information on
tinnitus prevalence, tinnitus severity, healthcare resource use for tinnitus, and hearing
difficulty prevalence.
Statistical analysis plan Creation of the survey dataset Once the fieldwork was completed,
DOXA collected data from its European partners and after internal checks provided to Mario
Negri Institute the 12 anonymous data files in text format, with the corresponding codebook
in English language. The 12 data files were managed by the team at the Laboratory of
Lifestyle Epidemiology, Department of Environmental Health Sciences of Mario Negri Institute.
Using the statistical package SAS, version 9.4 (SAS Institute, Cary, NC, USA), they performed
the input of the 12 textual data file into 12 corresponding SAS datasets, and then created a
unique final dataset in SAS. This dataset was checked for coherence and for the presence of
possible errors, cleaned, and finalized through the generation of queries which were
addressed by DOXA and its European partners.
Statistical analyses Statistical analyses required to achieve objectives has been conducted
by the teams from the Laboratory of Lifestyle Epidemiology, Department of Environmental
Health Sciences of Mario Negri Institute and the University of Nottingham, using SAS
statistical package. Prevalence of three working definitions of tinnitus (any, bothersome and
severe tinnitus) have been estimated through univariate statistical analyses (i.e.,
descriptive statistics for categorical data, including absolute or relative frequencies),
overall, by country, and in strata of selected demographic and socio-economic (individual and
country-specific) characteristics. Continuous variables have been summarized through the use
of means and standard deviations. Alternatively, they have been categorized, and thus
described through absolute or relative frequencies.
Multivariate analyses have been conducted to identify sub-groups of the population (e.g.,
based age-groups, low vs. high educated subjects) or clusters of countries (e.g., based on
income levels and regional groups) where tinnitus is more frequent. Thus, odds ratios (OR),
and the corresponding 95% confidence intervals (CI), were estimated through logistic
regression models after adjustment for selected individual-level characteristics.
ETHICAL AND ADMINISTRATIVE ASPECTS Informed consent At recruitment, information on survey
characteristics was given to all participants by suitably qualified professionals, who were
able to provide answers to any possible questions and to eliminate any concern respondents
may have. Information explaining the condition (i.e., tinnitus) was provided to survey
participants in the country-specific language in a clear, jargon free manner, using fully
understandable terms and language.
Although in EU countries, according to their current legislation, written consent is not
mandatory for this type of study (observational study collecting anonymized information), all
participants were asked to sign the informed consent form for participation in the study.
Since data was collected with CAPI method (using computer or tablet), participants had the
possibility to tick an electronic document in order to express their willingness to
participate in the study. No written signature was required.
The Ethics Committee of the study coordinator (Ethics Committee of Fondazione IRCCS Istituto
Neurologico Carlo Besta, Milan, Italy) notified that no preventative evaluation was required
for the present study, since anonymous data was collected (File number 37/2017).
Access to personal data and withdrawal from the study In this survey no sensitive personal
data (e.g., health, sexual lifestyle, ethnicity, political opinion, religious or
philosophical conviction), genetic information, or data involving tracking or observation of
participants was collected. According to other personal data, it was made clear that subjects
are completely free to withdraw their records from participation in the survey, and that the
consent given by participants in the study can be withdrawn, without any explanation or
justification. In this case, all data pertaining to the subjects in question was destroyed.
Ownership of the data Individual-level anonymous data sent from DOXA and its European
partners, and stored at the Mario Negri Institute, are the property of the study coordinator.
RELEVANCE AND IMPLICATIONS One of the expected outcomes of this study is the first estimate
of tinnitus prevalence from a Pan-European study. Given the lack of standardized tinnitus
prevalence questions and a global prevalence estimate, this study provides both standard
assessment measures and an estimate of how prevalent tinnitus symptoms are. In this study,
the investigators report the prevalence of any tinnitus using the same set of research
questions in various languages. This measure identifies the commonality of the condition.
Furthermore, the investigators assess the proportion of individuals having bothersome and
severe symptoms, who exert the true burden on financial and personnel resources in the
healthcare system. These estimates measured in a Pan-European study demonstrate the size of
the problem. This can guide resource allocation for implementing effective measures and
attract various stakeholders, including research funders, industrial and healthcare
organizations, to engage in needful endeavors for tackling tinnitus.
