Survey and data analysis of patients treated in a hearing aids

Purpose: To establish a profile of the patients treated in a Hearing Aids Grant Program of the Brazilian Ministry of Health, by analyzing the variables: age, sex, type and degree of hearing loss, number of aided patients, adaptation type (unilateral or bilateral), and adapted ear. Methods: This is a descriptive observational study, retrospective in a cross-sectional perspective, which included patients treated between February 2006 and July 2010, totaling 1,572 individuals. Results: Their ages ranged from 3 to 100 years, mostly elderly (52.8%), with no frequency difference between the sexes. The sensorineural (73.12%) and moderate (54.7%) hearing losses were the most frequent ones, except in children, in whom the degree found was more profound (45.3%). More than 99% of the patients were aided, 258 unilaterally and 1,302 bilaterally. Conclusion: Mostly patients presents 60 years old or more, with no frequency difference between the sexes. The sensorioneural and moderate hearing losses were the most frequent ones, except in children. More than 99% of the patients were aided and the conducts were defined based in the audiological diagnosis and patient’s needs.


InTRODUCTIOn
The human body's five senses exert great influence on all learning processes experienced by all individuals as they develop to their greatest potential.When there is an absence or deficiency in any of these senses, without efficient early intervention, a deficit in the reception of some stimuli may bring about significant consequences in the lives of individuals.
Within this context, auditory deficiencies appear as one of the most common and handicapping sensory deficits that may be present in a population (1) .In Brazil, the Health Minister (2) estimates that nearly 2,250 million persons have some degree of auditory loss.Nevertheless, few studies actually present prevalence and incidence figures addressing these deficiencies.
Individual hearing aids (IHAs) are a good option for reducing the sensory (3) deprivation and handicap, improving the auditory function, as well as the social interaction and quality of life of patients (4,5) .By amplifying the different modes and intensities of sounds, depending on the individual needs IHAs permit the wearer to efficiently use their residual hearing (5,6) .
One of the biggest difficulties encountered, during the selection and fitting procedures of IHAs, as it relates to the adjustment period, is the cost, which is quite high (7) .Focusing on the difficulty of community access, the Brazilian Federal Government created, in September 2004, a National Hearing Health Policy, through the decrees 587 and 589, which proposed a hierarchical network, by region and integrated, which includes since prevention and hearing health promotion, to diagnosing and fitting hearing prosthesis, including the auditory rehabilitation of children, adults, and the elderly (8) .
In 2005, the Universidade Federal de Santa Maria (UFSM) was integrated into this policy through the credentialing of the Hospital Universitario de Santa Maria, Department of Speech and Hearing Sciences and Service of Speech, Language and Hearing Sciences Care.Consequently, this institution established the Servico de Atencao a Saude Auditiva de Media Complexidade, to continuously distribute hearing prosthesis through the Nucleo de Selecao e Adaptacao de Proteses Auditivas (NUSEAPA), which serves patients from the centralwest sector of the State of Rio Grande do Sul.
From these understandings, important data were collected and some studies were carried out, which in turn have contributed with research addressing different aspects related to hearing.Through epidemiological studies, health problems are identified, described, and analyzed conforming to the different communities in which they occur, how they are distributed and its determinants in order to assess their impacts and plan actions for the change of situation (9) .
With this perspective, new research purports to reduce the negative consequences of auditory deficiencies though the global development of the individual.In Brazil, one study (10) describes epidemiological researches carried out in the area of Audiology and points out the importance of collaborative work between Speech and Hearing Sciences and Epidemiology to increase the efficiency of population work in the three hierarchical levels of the policy.
It should be noted that there still is a dearth of studies that present profiles of the patients being serviced in hearing health public programs, which would help with the planning of better services to individuals with hearing loss.
With regard to the services in Hearing Health Public Programs, two studies are highlighted: the profile of patients serviced in the Hospital Universitario da Universidade Federal de Santa Catarina through a Hearing Health State Program (11) and the audiological and epidemiological descriptions of the populations serviced in the Hospital das Clinicas da Universidade Federal de Minas, through an arrangement with the federal government (12) .
Based on the considerations previously presented, the present study had as an objective to elaborate a profile of the patients being serviced by the hearing aids grant program of the Health Ministry, based in UFSM.The variables analyzed were the following: age, gender, type and degree of hearing loss, number of patients fitted and not fitted, and type of fitting (bilateral or unilateral fitting).

METhODS
This study was previously approved by the Committee of research ethics of UFSM, no 0138.0.243.246-06, and is part of a registered project in the Gabinete de Projectos no 09731.All patients in this study signed a consent form.
This study obtained and analyzed data, using a descriptive observational and retrospective in a cross-sectional perspective.The data collection was carried out through the databank of NUSEAPA of the Institution, which was created and input using the Microsoft Access 97 software of Microsoft Windows 98.
Data from all the questionnaires belonging to patients from the NUSEAPA, hearing aids grant program, during the period of February 2006 through July 2010 were analyzed.
Those patients whose data were incomplete or whose audiological diagnosis was inconclusive were excluded from the analysis.The total sample comprised of 1572 questionnaires, from patients ranging in age between 3 and 100 years.
The following variables were considered: age, gender, type and degree of hearing loss, number of patients fitted and not fitted, and the type of aid, if bilateral or unilateral aid.Furthermore, associations between these variables were also analyzed.
With regard to age, the subjects were divided into five groups using the World Health Organization (2010) classification: preschool and children up to the age of 12, adolescents between the ages of 13 and 18, young adults aged 19 to 44, middle aged from 45 to 60 years of age, and the elderly which included those older than 60.
The data analysis with regard to audiological diagnosis, with regard to the type and degree of hearing loss, was carried out by considering both ears separately, since there were possibilities of having differences between the diagnoses for each ear in the same individual.
To determine and classify (13) the severity of the hearing loss, the average tonal limits were calculated for 500, 1,000, and 2,000 Hz.Normal results were considered to be from 0 to 25 dB; mild hearing loss from 26 to 40dB; moderate hearing Data of patients in a hearing health program CoDAS 2013;25(3):195-201 loss from 41 to 70dB NA; severe hearing loss was between 71 and 90dB NA; and profound hearing loss was deemed when the average was above 91dB NA.
Finally, a descriptive and statistical analysis of the data was performed using Statistica 9.0 and BioEstat 5.0 software.The level of confidence used was 95% (p=0.05).
The analysis of significance of the isolated variables (gender, age, type, and degree of loss) was carried out using the Lilliefors test.In order to test for relationships between the different variables and gender, a Pearson correlation was performed.Finally, the associations between gender and age, age and type of hearing loss, age and degree of loss, and degree and type of loss were carried using the χ 2 test.

RESUlTS
It was analyzed data from 1,572 patients, aged between three and 100 years old.With regard to the distribution of subjects by age, 830 (52.8%) were elderly, 302 (19.21%) were middle-aged adults, 222 (14.12%) were young adults, 150 (9.54%) were children, and 68 (4.33%) were adolescents.A significant difference in distribution was observed between the age groups (p<0.05).
The results of residuals for χ 2 analysis revealed that the difference between genders occurred because of a larger number of young adult females and elderly males in the sample than is estimated by the test, considering the determined of confidence level.
With regard to hearing condition, of the 3,144 ears considered, 2,299 (73.12%) presented sensorineural hearing loss.The second condition most found was mixed hearing loss in 653 (20.77%) ears, followed by 104 (3.31%) ears with conductive hearing loss and 88 (2.8%) with normal hearing.The results of the statistical analysis confirmed a difference in the distribution of the hearing loss types in the groups studied (p<0.05).
The distribution analysis of the subjects with regard to gender and age, and type of hearing loss, found no difference in the distribution of the type of hearing loss between gender (p=0.45)(Table 2).
Large percentages of sensorineural hearing loss were observed in all age ranges.residuals for χ 2 analysis proved the following: a larger number than expected of sensorineural loss in children, adolescents, and elderly; larger number than expected of conducted hearing loss in young adults as well as mixed hearing loss and normal hearing among middle-aged persons.
In the distribution of subjects by type of hearing loss such as sensorineural loss, of the 2,299 ears with this condition, 1,292 (56.2%) were from the elderly.Similarly, of the 653 ears with mixed hearing loss and 88 with normal hearing, 321 (49.16%) and 36 (40.91%) respectively were also observed within this age group.Conductive hearing loss percentages were mostly concentrated in the ears of young adults, with 53 (50.96%) of the 104 ears manifesting this type of hearing loss.
With regard to hearing conditions as they relate to degree of hearing loss, of the 3,144 ears of the subjects in this study, 1,720 (54.7%) presented moderate hearing loss, followed by 554 (17.62%) with severe hearing loss, 477 (15.17%) profound hearing loss, 305 (9.7%) mild hearing loss, and 88 (2.8%) with normal hearing.A statistical analysis confirmed significant differences between the degree of hearing loss exhibited (p<0.05).
A distribution of the subjects by gender and age with regard to degree of hearing loss revealed that there were no  significance differences between gender and degree of hearing loss (p=0.36)(Table 3).When analyzing the percentages taking into account the degree of hearing loss, it was noted that of the 477 ears of subjects with profound hearing loss, 136 (28.51%) were from children.Of the 305 ears with mild hearing loss and of the 1,720 with moderate hearing loss, 197 (62.62%) and 1,077 (64.88%) were found in the elderly respectively.Of 88 ears with normal hearing, 26 (29.55%) were from middle-aged persons.A residuals for χ 2 analysis revealed that these values were within the upper limits of the confidence interval band (a=95%), that is, they were larger than estimated.The same test also revealed that there were more ears of adolescents and young adults with profound hearing losses than predicted, since these groups presented less moderate and mild hearing losses than the other groups.In the ears of the adolescents, values lower than expected were found with relation to normal hearing.
Associations made between the type of hearing loss and the degree of hearing loss revealed that for all types of hearing loss, the most prevalent degree was the moderate type.Using the residuals for χ 2 analysis, it was seen that the ears of subjects with sensorineural losses presented mostly with mild, moderate and profound hearing losses, and that those with conductive hearing loss were mostly concentrated within the moderate hearing loss range (Table 4).
Addressing the number of patients fitted, the type of fit, if unilateral or bilateral, and if a unilateral fit, which ear was fitted, it was revealed that only 12 (0.8%) were not fitted with IHA (Table 5).

DISCUSSIOn
In Brazil, there is a dearth of studies presenting the profiles of patients seen in hearing health public programs, making it difficult to adequately plan collective health prevention and intervention measures that would address the real needs of the population.Within this context, epidemiological studies that delineate the profiles of these patients are basic for helping with the process and best service delivery to persons with hearing loss.
The analysis of the data being seen by the Programa de Concessao de Proteses Auditivas, with regard to the age at  which time they seeked services, revealed a prevalence of elderly with more than 60 years of age, supporting the results found in other studies (12)(13)(14) .This reflects the changes in aging that start to occur from the age of 30, which leads to progressive hearing loss (15) .Therefore, it should be considered that the gradual increase of hearing loss, the time of auditory deprivation (16) , and the difficulties related to the loss encountered motivate the individuals to seek audiological services just several years after the initial identification.Demographic Census data reveal that the elderly already comprise 11.6% of the general population, reaffirming the increase in longevity and the reduction of mortality rates occurring within the last decades.Thus, the aging of the population and the quality of life in this age group has been a focus of Brazilian public health activity.As alluded to in international studies (17) , epidemiological studies have the potential of contributing to the knowledge about presbycusis, its genetics, environmental, and gender aspects; identifying potential intervention strategies; and improving existing treatments, such as the fitting of prosthesis.
In keeping, it is possible that new and rising investments of the Federal Government Programs can help with the promotion of hearing health, through actions directed at communities and professionals (from community health workers to doctors -who are responsible for referrals), so that a diagnosis does not occur years after the identification of the deficiency.
Regarding the low percentage of children seeking these services, it may be that this center is for average care, therefore serving persons older that three.In the meantime, it is noted that other research have also found less representation of children receiving audiological diagnostic services (12,18) , revealing the importance of implementing a universal neonatal hearing screening program and the implementation of programs and campaigns specifically educating parents with regard to the identification of hearing loss in their children (18) .
Taking into account the gender variable, in this study no differences were found between the number of men and women serviced, agreeing with the data of population serviced in another hearing health program in the country (12) .With regard to the prevalence of hearing loss, a study carried out in Asia did not find any differences between genders (19) .Already, some Brazilian studies have found larger numbers of men with hearing loss (13,14) , and others in women (20,21) , without any confirmation as to which gender has a larger incidence in the global population.
In the present research, a relationship was found between gender and age of the sample.The prevalence of hearing loss among women, as age is considered in adults, has also been presented in other studies (11,20,21) .When considering the elderly, just as has been found in this analysis, researchers indicate a larger prevalence of hearing loss among males, also indicating that with aging men are four times more likely to present with some hearing issue when compared to females (17,22) .Thus, it was observed that there is no consensus in the national and international literature with regard to the prevalence of hearing loss when gender and age are considered.
With regard to the type of hearing loss, sensorineural hearing loss was observed as having a larger prevalence rate in the services addressed, as was unanimously found in the references obtained for this research (12,15,(20)(21)(22)(23) .In studies carried out in infant populations, sensorineural hearing loss is most prevalent; however the percentage of conductive hearing loss has increased (11,24) .
The large number of sensorineural hearing loss found in this study is justified by the elevated number of elderly patients and the presence of presbycusis that causes the increased percentage.Furthermore, since it is a program which grants hearing prosthesis, it is understood that few patients come with any modifications to the external or middle ear, since they experience an evaluation by a doctor and only in extreme cases are they referred for a fitting.
When verifying any associations between gender and type of hearing loss, there were no significant relationships between the variables.Prevalence data were obtained for sensorineural hearing loss in both men and women, agreeing with results found in other studies (14,25) .
Sensorineural hearing loss was the most found in all age ranges.The fact that larger than estimated numbers of ears of children, adolescents, and the elderly presented with this type of hearing loss, as verified through residuals for χ 2 analysis, can be justified by several factors.In the elderly, presbycusis may be the most common cause for this hearing deficiency.The degeneration of the cochlea caused by the presbycusis , in addition to harming the auditory function as a whole, is characterized by the hearing loss mentioned, agreeing with other studies.Studies with children already indicate that pre-, periand postnatal factors can contribute to hearing loss, primarily sensorineural.In adolescents, the increase in the incidence of hearing loss, primarily of the sensorineural type, also has been observed in international studies (26) , correlating with the increase in hearing thresholds with the elevated levels of sound pressure to which adolescents are exposed to on a daily basis.The same study also noted that adolescents underestimate hearing problems or tinnitus, or to temporary changes in thresholds after being exposed, which leads to a delay in searching for diagnostic centers to carry out treatment measures.
The fact that the residuals for χ 2 analysis test points to numbers above those estimated by the tests of ears with conductive and hearing losses in young adults, and mixed hearing loss in middle-aged adults, can be justified by one of the most commonly fitted pathologies with conductive hearing loss -otosclerosis.This ailment is one of the most common causes of hearing loss in adults, with an incidence more common among women aged 20-40 years (27) .In more advanced ages, otosclerosis may be associated with sensorineural loss, resulting in a mixed loss (11) .In cases in which surgical treatment is not appropriate, referral for hearing prosthesis would be indicated.
In the analysis of the degree of hearing loss, a larger concentration of the moderate hearing loss was observed, agreeing with results found in demographic research (13) , and with two Brazilian hearing health programs (11,12) .Similarly, the prevalence of moderate hearing loss will remain in the distribution keeping in mind the gender of the subjects, though moderate and severe hearing are represented in larger percentages, following what resulted from the analysis of these variables (14) .
The statistical analysis of the degree of hearing loss revealed an elevated number of children with profound hearing loss, as has been found in other studies carried out with this population (11,12,24,28) .It is known that one of the most frequent causes of congenital hearing loss is maternal infections, and within these, the most prominent is the Rubeola Congenita syndrome (29) .In spite that the vaccination programs have been successful with reducing the number of cases with this ailment in Brazil, still hearing losses with this etiology continue to be found.
Already among the causes for acquired hearing loss, bacterial meningitis (29) has been identified; therefore periodic hearing evaluations must be made in all children presenting with this ailment, since the hearing loss may appear after all symptoms have ceased.
Both hearing losses caused by congenital rubella and bacterial meningitis present with sensorineural loss patterns with degrees varying between severe and profound, therefore justifying the high degree between the ears of children analyzed in this study.
With regard to the prevalence of mild and moderate hearing loss in the elderly, this is justified since the degree of presbycusis for 500, 1,000, and 2,000 Hz is generally between 15 and 60 dB NA (15) .This data was also found in international and national studies (17,22) .In spite that changes in aging are expected in middle-aged persons, the number of subjects in this age range of this study with normal hearing still remained above the estimated number.It should be noted that in this study the Davis and Silvemann (13) classification was used.It considers the tritonal average in the 500, 1,000, and 2,000 Hz frequencies.Therefore, the causes with reduced tonal thresholds in only high frequencies, common in the initial stages of presbycusis, were not classified as presenting with hearing loss.
The number of adolescents and young adults with profound hearing loss may have the same justification as the high incidence of this hearing loss type in children.Many adolescents and young adults are fitted with IHAs as children in other settings and come to NUSEAPA when older to request new aids and follow-up services through the Hearing Health Program of the Federal Government.
The association between the type and degree of hearing loss confirmed previously confirmed data pointing to increased occurrence of moderate loss in any type of hearing loss.Furthermore, the high degree of concentration of sensorineural hearing loss of the mild, moderate, and profound types is justified since they are the most found in the elderly and children, respectively (11,12,17,22,24,28) .These two age ranges, together, account for more than 60% of the total sample.
In cases of conductive hearing loss, the causing pathologies for those with fitting possibilities, like otosclerosis, do not exceed the moderate loss degree.Therefore, it is justified that there is a larger concentration of conductive hearing loss in subjects of this study.
With regard to prosthesis, in this study, it was observed that more than 99% of the patients were fitted, with differences between bilateral and unilateral fittings.A bilateral fitting offers advantages such as better localization of the sound source, binaural summation, elimination of head shadow effect, better speech discrimination in the presence of noise, and diminished efforts to hear (6) .Because of the advantages described, a bilateral amplification recommendation is preferred for all candidates, except when there is a contraindication, such as big differences in auditory thresholds between each ear, severe problems with motor skills, changes in auditory processing, and rejections due to esthetics or finances (6) .As a consequence, these are considered at the moment of selecting and fitting the auditory prosthesis in the service being addressed, and when possible, a bilateral prosthesis is implemented, since it is believed that they provide better auditory results, and further, a better quality of life to the users of hearing prosthesis.

COnClUSIOn
The majority of patients in this study were 60 years of age and older, without a frequency count difference between genders.Sensorineural hearing loss type and moderate hearing loss were the most frequently diagnosed in all genders and age ranges studied, except in children where profound hearing loss was mostly identified.
With regard to fitting, it was observed that of the 1,572 patients seen, more that 99% were fitted, 258 unilaterally and 1,302 bilaterally, which is the preferred identified procedure in accordance to their audiological diagnosis and needs.

Table 1 .
Distribution of subjects according to the variables gender and age group *Significant values (p<0.05)-Pearson's Correlation Test, χ 2 test of association and χ 2 residual analysis

Table 2 .
Distribution of subjects, considering gender and age group according to the variable hearing condition (hearing loss) per ear *Significant values (p<0.05)-Pearson's Correlation Test, χ 2 test of association and χ 2 residual analysis

Table 4 .
Distribution of subjects, considethe variables type and degree of hearing loss, per ear *Significant values (p<0.05)-Pearson's Correlation Test, χ 2 test of association and χ 2 residual analysis

Table 5 .
Distribution of subjects according to the variables adaptation of IHAs, unilateral, bilateral and adapted ear

Table 3 .
Distribution of subjects, considering gender and age group according to the variable hearing condition (degree of hearing loss) *Significant values (p<0.05)-Pearson's Correlation Test, χ 2 test of association and χ 2 residual analysis