Epidemiological profile of a hearing-impaired population Perfil epidemiológico de uma população com deficiência auditiva

Mailing address: Débora Soares Jardim Rua Alessandra Salum Cadar, 651/202, Buritis Belo Horizonte – MG – Brasil CEP: 30575-190 E-mail: defonobh@yahoo.com.br ABSTRACT Purpose: to characterize the epidemiological profile of the hearing impaired population assisted in a public service regarding sociodemographic, clinical, assistance, communicative and comportamentals aspects. Methods: observational descriptive cross-sectional study conducted with secondary data. The sample consisted of 307 users, from May 2009 to May 2011. Was used protocol for the authorization to deliver Personal Hearing Amplifiers. Results: there was predominance of the users are female, seniors over 60 years, incomplete primary education and retiredes. Higher prevalence of users who had exams basic hearing at the time of the evaluation, moderate sensorineural hearing loss, presbycusis etiology. Regarding behavioral aspects, the users reported to present auditory reactions without the Personal Hearing Amplifiers and orality. Conclusion: the results of this study allow initially the planning of operational strategies and actions that can better serve the user , especially with more attention to the elderly over 60 years and intensifying guidance to mothers and pregnant women on the need to carry out the Newborn Hearing Screening to detect early hearing loss and beginning of the rehabilitation process.


INTRODUCTION
The prevalence of hearing loss in Brazil is still unestablished because only three national populationbased studies 1 have been performed describing hearing impairment through the World Health Organization protocol 2 .Two of these studies were conducted in Southern Brazil 1,3 and one in Northern Brazil 3 .In Canoas, RS (Southern Brazil) 3 , 26.1% of the population presented some level of hearing impairment: 19.3% presented with mild hearing loss and 6.8% presented disabling hearing loss.Itajaí, SC (Southern Brazil) 1 , a prevalence of 7% of disabling hearing loss was detected in the municipality.In Monte Negro, RO (Northern Brazil), hearing loss was detected in 15.5% of the population: 11.7% mild and 3.8% debilitating 4 .
In 2004 in Brazil, where each region has its own population characteristics, the Brazilian Unified Health System (SUS) was amplified to provide assistance to people with hearing loss through the National Policy on Hearing Health Care (PNASA) proposed by the Ministry of Health 5,6 .Hearing health care services include appointments with speech therapists, medical specialists, psychologists and social workers.These services include procedures for diagnostic purposes such as audiological evaluations, indications for hearing aids and/or cochlear implant surgeries and hearing rehabilitation 5,6 .Therefore, establishing epidemiological data from these services is fundamental for appropriate planning and decision-making regarding population health, real community needs and determinants of health and disease.A review of different epidemiological studies in Audiology in Brazil revealed a greater proportion of, and interest in, hearing impairment associated with labor with a deficit of scientific studies regarding the elderly and neonatal populations 7 .
A study investigating SUS health care services for people with disabilities found that, despite the advances of the last few years, Brazil possesses an inadequate regulation system which does not allow for the identification of best practices and establishment of epidemiological and technical-scientific guidelines for articulating and generating greater consistency in the healthcare provided to populations with disabilities 8 .Considering this context, this study aimed to obtain the epidemiological profile of the hearing impaired treated at the public Micro-regional Hearing Health Board (HHB) of a health region in the state of Minas Gerais including the clinical, service, communicative and behavioral aspects of care.

METHODS
This study was authorized by the city manager and the Ethics Committee in Research (COEP UFMG, protocol CAAE -0671.0.203.000-11) which dismissed the need for a term of free and informed consent.This descriptive, observational, cross-sectional study utilized secondary data from records of a hearing health care center.The HHB is responsible for the hearing health services of a region with 623,582 residents, where 23,482 (3.76%) have some hearing loss and 5,503 (0.88%) present disabling hearing loss, according to the Brazilian Institute of Geography and Statistics (IBGE) 9 .It is the responsibility of the HHB to include patients of the hearing health care services in the region into the State Hearing Health Program 10,11 .The HHB also evaluates candidates for the use of personal sound amplification (PSAP) products referred by decentralized audiologists of their region, defines clinical priorities of referrals according to monthly quotas 12 , monitors scheduling of consultations in the Hearing Health Services and follows patients who receive PSAP and are in speech therapy for rehabilitation in their health regions 10,11 .
The data for this study was collected from the protocol for evaluating and authorizing PSAP proposed by the Hearing Health Regulatory Board, and therefore the HHB, which uses a standardized questionnaire with variables in the following categories: sociodemographic (age, sex, profession, residency, educational attainment level, functional level); clinical (probable cause, type and degree of hearing loss); service (previous use of PSAP, type of PSAP, adaptation, indication by an otolaryngologist for PSAP, type of exams undergone, current participation in speech therapy and conduct of the HHB); communicative (degree of motivation to use PSAP, sociocultural context: autonomy for using PSAP, use of oral language, acceptance, socialization in relation to the hearing loss, family).Files of patients evaluated for a PSAP from May 2009 to May 2011 were utilized in this study.Files with incomplete data (more than 20%) or lost Evaluation for the Authorization and Concession of PSAP questionnaires were excluded from analysis.From 374 patient files, 29 were excluded due to incomplete date and 38 had missing questionnaires.Therefore, 307 people were included in the study with ages ranging from 2 to 95 years.Patient age was classified according to IBGE categories: child, 0 to 14 years; teenager and adult, 15 to 60; elderly, above 60 years old 13 .
The classification of degree of hearing loss utilized in the patient files followed the Loyd and Kaplan criteria 14 , where, when calculating the mean of pure tone thresholds of 500, 1000 and 2000 Hz frequencies, the normal hearing threshold is up to 25 dB HL, mild hearing loss is 26-40 dB HL, moderate loss is 41-55 dB HL, moderately severe is 56-70 dB HL, severe is 71-90 dB HL and profound hearing loss is greater than 90 dB HL.Analysis of degree of hearing loss was done in the right and left ears separately according to the files.
The data was registered in a Microsoft Excel database.The Statistical Package for the Social Sciences (SPSS, Version 15) was utilized for data analysis.Categorical variables were distributed in frequency tables.Central tendency and variation (average, mode, standard deviation, minimum and maximum) measures were used with continuous variables.
The Student's t-test was used to test for associations between age and previous use of PSAP.To analyze associations between the best degree of hearing loss in the better ear, the ANOVA test and Bonferroni correction were used.A 0.05 (5%) significance level was established with 95% statistical confidence intervals.

RESULTS
Of the 307 patient files included in the sample, 55.7% were of females.The patient ages varied from 2 to 95 years with an average of 57.37 and a standard deviation of 21.03 years.Children were 6%, teenagers and adults were 39% and the elderly were 55% of patients treated.
Tables 1, 2, 3 and 5 show the descriptive analysis of the research variables according to the thematic distribution of the questionnaire utilized.Analysis of the sociodemographic data revealed that most of the patients had an incomplete elementary education and were retired (Table 1).Regarding clinical data, 81.17% of the patients presented hearing tests (audiometry, tympanometry and speech audiometry) during the evaluation and the most prevalent etiology was presbycusis (62.32%).
Sensorineural was the most frequently observed type of hearing loss in both ears.The analysis of auditory thresholds revealed a moderate level of hearing loss was the most observed in both ears, followed by moderately severe (Table 2).the better ear is different.The ANOVA test supports a relation between age and degree of hearing loss in the better ear (p<0.001).
Figure 1 shows that the median age of the patients in relation to the degree of hearing loss (normal, mild, moderate, moderately severe, severe and profound) in

Figure 1. Comparative analysis between degrees of hearing loss in the better ear and age
The ANOVA test adjusted by the Bonferroni correction was used to determine where statistically significant differences between groups of similar hearing in the better ear (normal, mild, moderate, moderately severe, severe and profound) and average age.It was possible to detect a statistically significant difference in the mild, moderate, moderately severe and severe hearing loss groups.A statistically significant difference in average age was detected between the mild and moderate groups in comparison with the profound hearing loss groups.The group with moderately severe hearing loss in the better ear presented a significant difference in average age as compared to the severe and profound hearing loss groups.Average age was also statistically significantly different among the severe and profound hearing loss categories.
Service data shows that wait time 1, or the time between first contact with the HHB and the evaluation for authorization and concession of a PSAP, was mostly between 0 to 3 months and wait time 2, or the time between the evaluation and appointment at Hearing Health Services (HHS), was 3 to 6 months.Most (82.3%) of the patients reported not previously utilizing a PSAP, 93.81% did not have a history of speech therapy, 78.6% had referrals from a otolaryngologist for the use of a hearing aid and 93.95% were classified as medium complexity (Table 4).
When applying the Student's t-test among the variables: the average age of the patients that had previously used a PSAP was lower than the average age of patients with no prior PSAP use (p<0.001)(Figure 2).
The communicative aspects reveal a predominance of patients: going to the evaluation for the authorization and concession of a PSAP unaccompanied; reporting hearing reactions without the use of a PSAP; were motivated to use a PSAP; are independent enough for utilizing the device; can verbally communicate; accept their hearing status; define their behavior as calm and under control; and, present adequate socialization.(Table 5).

DISCUSSION
Analysis of data from the patients of the Microregional Hearing Health Board revealed a greater number of residents from the city hub of the HHB.This is due to monthly quotas for first consultations for adaptation of the personal sound amplification products.The State established criteria for the definition of monthly quotas for each health region maintaining proportionality.The city hub of the health region has a greater population and therefore a greater amount of people receiving hearing health care 12 .It is important to note that referrals to the HHB from other municipalities were less than expected and actions should be taken to increase hearing health care coverage in the region.
The increased prevalence among the elderly (above 60 years) supports other studies from different regions: Santa Maria (RS) 15 , Belo Horizonte (MG) 16 , Montes Claros (MG) 17 and Canoas (RS) 3 .The low number of children evaluated may indicate late diagnosis or intervention, which also occurs in other municipalities such as São Paulo (SP) 18 and Ribeirão Preto (SP) 19 .However, the importance of early detection and the need for investments in the active search for children with the State Newborn Hearing Screening Program.
Educational attainment and employment profiles were consistent with expected levels for the elderly population in Brazil which has an average of 4.2 years of formal education and are mostly retired 13 .Furthermore, a patient satisfaction survey of the hearing health care services of northern Minas Gerais also obtained this patient profile 17 .
Presbycusis, as the cause of hearing loss with the greatest incidence, was consistent with the population profile considering its direct relationship with age.A study in Rio de Janeiro (RJ) 20 found that 71.8% of the population with presbycusis had low educational attainment and received one to two minimum monthly wages.This study suggests that this population is more prone to health problems due to barriers in access to information and health care.A study from São Paulo (SP) 21 with 53 senior citizens (average age of 71.7 years) found that 83% presented hearing loss characterized as presbycusis and PSAP was used 3.8%.
Among those over 60 years old, 55% did not have previous access to a PSAP.In Itajaí (SC) 23 , a study also found that, due to insufficient financial resources, this population was not able to utilize PSAP until the establishment of Hearing Health Care Services.
Variables with communicative aspects revealed positive perceptions regarding the hearing rehabilitation process, but the need to accompany patients during the adaptation process in order to guarantee the effectiveness of PSAP.A study 24 on the satisfaction level of PSAP users determined that satisfaction was influenced by characteristics of the service received and aspects related to receipt, use, entrance into the health system, use of devices and monitoring of adaptation.In health promotion programs designed for diabetics 25 , the knowledge of the professionals involved in care regarding patient feelings, concerns, fears, conflicts, and needs is important for establishing relationships with the patients and develop strategies to reach the desired results.
When analyzing wait time for the evaluation and concession of PSAP, the result was similar to a study from north Minas Gerais 17 .The time between evaluation and the first appointment with the Hearing Health Care Services is related to the quotas established for each health region with patients waiting between 3 and 6 months to begin the PSAP adaptation process.
In developed countries such as Finland 26 , people with hearing impairments can access PSAP from the public health system and wait up to two years for receipt of the device.Children are priorities compared with the elderly as established by PNASA.Although in this study, the wait time evaluated was only of the first appointment in the Hearing Health Care Services, it is expected that the total time for acquiring a PSAP in this health region is similar to the wait time in Finland, or two years.One of the most important problems of national health systems are excessive wait times, being that these may even be traumatic.There are strategies which can be used to manage this situation either from an equity or efficiency perspective: increase supply by increasing suppliers, control demand, use health indicators and prioritize patient groups 27 .
There have been many advances in care for the hearing impaired in Brazil 28,29 .An evaluation 29 of the National Policy on Hearing Health Care from 2004 to 2011 found a 113% increase in hearing health services coverage and 61% more diagnostic procedures of medium to high complexity; yet, important problems of regional inequalities persist.There is a need to advance the scientific literature with data on rehabilitation and health promotion 30 so that a better understanding of the hearing impaired population and the services they receive, including coverage and efficiency, may be possible.

CONCLUSION
This study found that the population receiving care at the Micro-regional Hearing Health Board was mostly female, elderly, with an incomplete elementary education, with presbycusis, sensorineural hearing loss, moderate degree of hearing loss, and motivated to begin the hearing rehabilitation process.Regarding health care and behavioral aspects, a greater portion of patients had no prior use of PSAP, presented referrals from otalaryngologists, had not undergone speech therapy, used verbal language and reported good acceptance of their hearing impairment.
The results of this study support the planning of operational strategies and actions to better serve patients, especially senior citizens, and inform mothers and pregnant women of neonatal hearing screening for the early detection and rehabilitation of hearing loss.Therefore, this study presented a reflection of current care practices regarding the importance of knowing the population of a public service offered in the context of the National Policy on Hearing Health Care.However, further prevalence studies in the hearing health care network are needed to understand the influence of social determinants on health and hearing impairments.

Table 1 .
Sociodemographic data of the population receiving care at the Micro-regional Hearing Health Board from May 2009 to May 2011 * The n varies due to missing data.

Table 2 .
Clinical data of patients of the Micro-regional Hearing Health Board from May 2009 to May 2011

Table 3 .
Comparison of hearing levels of the better ear and average age of patients Legend: p=probability of statistical significance.*Significant p-values -Bonferroni Correction.

Table 4 .
Service data of patients of the Micro-regional Hearing Health Board from May 2009 to May 2011 Legend: * The n varies due to incomplete data.** Wait time between contact with the Micro-regional Hearing Health Board and the evaluation for the authorization and concession of a Personal Sound Amplification Product.*** Wait time between authorization and concession of PSAP and appointment in the Hearing Health Service.T Figure 2. Comparative analysis between age and use of a personal sound amplification product

Table 5 .
Communicative aspects of the population receiving care at the Micro-regional Hearing Health Board between May 2009 and May 2011.
*The n varies due to missing data.