What is an impact of hearing aids primarily fitted for presbyacusis on quality of life in patients complaining of tinnitus: a pilot study

Abstract

Objective

To assess the secondary effect of hearing aids primarily fitted for presbyacusis and their impact on the quality of life of patients complaining of tinnitus.

Design

Pilot case study

Study sample

Adults with presbyacusis hearing loss were recruited in the Asker ENT clinic in Norway. Twenty consecutive patients were included in the pilot study.

Methods

Twenty patients who were diagnosed with presbyacusis and additional tinnitus by the hearing tests (pure tone audiometry and speech audiometry) and medical interviews were recruited for the study. The level of their tinnitus distress was measured by the Tinnitus Handicap Inventory (THI) before and around 2 months after the hearing aid fitting. The results were afterwards statistically analyzed using paired sampled t-tests in Excel.

Results

The data showed that hearing aids fitted primarily for presbyacusis can improve the quality of life in individuals suffering from tinnitus (p = 0.001504). In our sample, women showed higher levels of complaints about their tinnitus, compared to men. We found that age was an influencing factor on the outcomes of hearing aid usage for both presbyacusis and tinnitus, as people in this study before the age of 75 benefited less than patients above 75 (p = 0.005). All patients with moderate hearing loss in our sample showed significant improvement in their quality of life in regard to their tinnitus complaint, with a statistical value of p = 0.044. Also, patients with the lower levels of THI (slight and mild) were the groups who had the most clinically significant improvements in tinnitus distress. Finally, while analyzing the answers to all the THI questionnaire questions from the patients who did not show improvements in THI scores, a pattern of having trouble sleeping was detected as the most probable factor.

Conclusions

The results showed that hearing aids fitted primarily for presbycusis can have a positive influence on the perception of tinnitus and their quality of life.

Background

Presbyacusis is an irreversible, age-related hearing loss and can be defined as a bilateral, progressive, sensorineural type of hearing loss. “It is one of the most common conditions affecting adults as we age” [1], p. 1). Knowing that we live in an aging population, we can only expect this problem to grow. At present, statistically speaking, one in three people aged between 65 and 74 has a hearing loss and one in two from 75 years old and above [2]. To add to it, aging is the most common cause of hearing loss worldwide [2,3,4].

There are several aging processes affecting the auditory system, which impact hearing, like hair cell damage, atrophies at the basal turn of the cochlea and the stria vascularis, stiffing of the tympanic membrane, or loss of neurons and nerve fibers [3]. Depending on which of these processes impacts hearing the most, [5] suggested four main types of presbyacusis: sensory, neural, metabolic, and mechanical one. Those types are not exclusive and can be present in combination and mixed forms [6, 7].

Age-related hearing loss can have a profound impact on different dimensions of quality of life (physical, economic, social, and emotional one), as it has been connected to issues such as social withdrawal, isolation, dependency, loneliness, frustration, communication problems, anxiety, and depression [8, 9]. It is progressive in nature, which means these issues can become more severe with time if the patient does not seek rehabilitative help. It is also worth noting that hearing loss got recognized by The Lancet Journal to be the biggest preventable risk factor for dementia [10].

Furthermore, age-related hearing loss often comes with additional tinnitus which practically speaking means that a patient’s quality of life is doubly impacted [11]. Tinnitus can be described as a phantom perception of sound [12]. It is known as a sensation of sound within the ear, despite the absence of external acoustic stimuli [13]. Combined with hearing loss, it can lead to different psychological and social effects, including loneliness, depression, social isolation, extreme fatigue, or inability to follow conversation. Long term, it can lead to chronic exhaustion, concentration struggles, or poor sleep [13, 14]. Examination of these symptoms helps to determine how significant the patient’s handicap is. Several outcome measures were created in order to do so and have been proven to be reliable tools for measuring distress caused by tinnitus, and furthermore, their high scores can be reflected as a significant impairment in quality of life [13, 15,16,17]. Tinnitus Handicap Inventory is one of the most popular of them. The original THI questionnaire was invented in 1996 by C.W Newman and was subsequently followed by the screening version (THI-S) in 2008, by the same author. The idea behind THI was to create a self-reported measure, which could help clinicians to understand the impact of tinnitus on a patient’s daily living and classify the severity of it. The severity scale consists of 5 levels. Grade one is classified as a slight handicap, in patients who scored up to 16 points. The next grade is mild, which is between 18 and 36 points. The moderate scores are from 38 to 56 points. Then the severe grade is from 58 up to 76 points and lastly catastrophic one from 78 up to 100 points. The THI questionnaire consists of 25 questions in which the patient is able to score 0, 2, or 4 points from three different subscales: functional, emotional, and catastrophic. The functional dimension, which includes 11 questions, exposes the patient’s mental, social, and physical functioning limitations. The emotional subsection includes 9 questions, which deal with the emotional reactions to tinnitus, like frustration, anger, anxiety, or depression. The last type of questions (catastrophic ones) are examining severe responses to tinnitus, like the perception of control over it, feeling trapped, or classifying it as a severe disease [18, 19]. It is worth noting that even though different subcategories exist, only the total score is clinically useful [20]. However, examination of individual questions can provide us with insight as to what the patient is going through and their tinnitus etiology [18, 21].

Epidemiologically, it is estimated that 3 out of 10 people with hearing loss have additional tinnitus, while in a group of 10 people with primary tinnitus complaint, 9 of them have hearing loss [22,23,24]

Because presbyacusis-related hearing loss and tinnitus often coexist, it is important to look at the influence of different rehabilitative management for one complaint on the other, especially knowing that common clinical practice with tinnitus patients is hearing aid fitting. The effect of hearing aids on tinnitus management has been the subject of several Cochrane reviews. One of them [25] concluded that there is no evidence of the direct effect of hearing aids alone or as a combination of devices in affecting tinnitus management outcomes. On the other hand, several recent studies focused on changes in tinnitus distress due to hearing aid fitting in patients with hearing loss consistently show improvements. These improvements in patients’ tinnitus distress results vary from clinically significant improvement of 34% in THI scores [26], to 28% of clinically significant improvement [27] to 16% improvements which were not clinically significant [28]. Some research studies focused on older patients (between the age of 60 and 70) found a clinically significant improvement of 53% on the distress scores for tinnitus following hearing aid fitting [29]. We can clearly see that there are a lot of inconsistencies in the existing data and an indication that particularly older patients may benefit significantly from hearing aid fittings for both hearing loss and tinnitus.

Aim of the work

The aim of this study is to discover if when these issues are coming together, they can also be improved together. The idea behind this work is to investigate if the quality of life with presbyacusis and tinnitus can be improved with hearing rehabilitation based on the fitting of hearing aids. The leading thought of this study is that tinnitus is a byproduct of presbyacusis, yet it is also responsible for decreasing patients’ quality of life. The main question to answer by this research is if by fitting hearing aids and improving hearing, can we also decrease the level of tinnitus handicap, which directly impacts life’s quality of elderly patients?

The hope is that given the same background of tinnitus in patients, some patterns and possible benefits of hearing aid fittings can be found, like as follows: Who can benefit the most? Who needs additional help beyond hearing aid fitting? Are there any patterns in improvements? Can improvement be clinically significant? Does gender or age make a difference?

We hope that setting a focus on presbyacusis with additional tinnitus problems can contribute to the elimination of the gap in the literature and help with everyday audiological care.

Methods

Participants

To answer if hearing aids primarily fitted for presbyacusis can help with a quality of life with tinnitus, a consecutive group of 20 patients who suffered from presbyacusis-related hearing loss and complained of tinnitus were recruited. The mean age of the group was 73.4 with the standard deviation of 7.4.

To be qualified as a presbyacusis patient, the following criteria had to be met:

• Age above 60 years old (no upper limit)

• Bilateral, symmetrical, and sensorineural type of hearing loss

• Speech discrimination not lower than 70% on each of the ears (to avoid other confounding factors of possible retro cochlear hearing loss)

• No medical history of usage of ototoxic drugs

• General good health

• Hearing problems which have started in the elderly age (not before 60 years of age)

To be qualified as a patient with secondary complaint of tinnitus, the following criteria had to be met:

• Tinnitus was not a main complaint of the patient

• Perception of tinnitus had the same timeline as patients’ problems with hearing (not before the age of 60)

• Tinnitus was perceived on both sides just like the hearing problems

• Tinnitus had to be subjective and sensory (objective and pulsatile types were excluded)

All patients had primary complaint of hearing loss and secondary complaint of tinnitus. Furthermore, all the patients had no prior experience with hearing aids or any kind of tinnitus rehabilitation. No gender, age, severity of hearing loss, or level of tinnitus handicap limitations were set.

Outcome measure for tinnitus

The THI questionnaire was chosen as the outcome measure for tinnitus, as it is one of the most reliable tinnitus questionaries [20]. The main advantage of THI is that, while covering a variety of domains, we can explore and understand the psychological aspects which are closely connected to the patient’s perception of quality of life [18]. It is also easily quantifiable as if the score lowers by at least 6–7 points, the change is considered clinically relevant [30]. Clinically relevant in the THI questionnaire is defined as that the patient’s quality of life improved, thanks to tinnitus having less impact on their daily activities [30].

Plan of study

Patients from the study were referred to the audiologist in the ENT clinic by their general practice doctor. It is a standard procedure in Norway as both audiological care and auditory therapy are part of the public health care system. This results in free hearing aids being available to all patients in need regardless of their financial situation.

No prior hearing tests were taken before the appointment. Patients were referred to the audiologist with the suspicion of age-related hearing loss, based on the symptoms they described to their general practice doctor. Furthermore, they were informed about the possibility of hearing aid fitting at the ENT practice.

All patients included in the study were fitted with the best possible hearing aid option for their individual hearing needs (highest level of available hearing aids e.g., Lumity RT/L 90 in Phonak, Pure C&G IX 7 in Signia and Real 1 in Oticon which were the newest types on the market at the moment of the completing this study) within a care-as usual auditory rehabilitation plan for the department. The care-as-usual protocol included three audiological appointments. The tinnitus maskers were not turned on during this study as we tried to examine the impact of amplification on tinnitus alone.

On a first appointment, the following steps were taken:

• 1. Otoscopic examination

• 2. Tympanometry, to exclude any middle ear issues

• 3. Medical interview, to gather as much information as possible about timeline of hearing problems, patients’ experience of hearing issues, tinnitus-caused distress

• 4. Pure tone audiometry (air conduction 0.25–8 kHz and bone conduction 0.5–4 kHz), to see what kind and level of hearing loss patients have

• 5. Speech audiometry, to see patients’ level of speech discrimination

• 6. Explanation of results and linking them into patients’ everyday life situations and difficulties

• 7. Presentation of available hearing aids and choosing one together

• 8. Description of THI questionnaire to the patient

• 9. Setting up a new appointment

On a second appointment, which was typically 3 to 4 weeks later, due to waiting list, the following steps were taken:

• 1. Otoscopic examination

• 2. Hearing aid fitting using the individual user’s hearing thresholds from pure tone audiometry test and in situ audiometry

• 3. Showing patients how to use, clean, and take care of hearing aids

• 4. Collecting a score of the THI questionnaire before the hearing aid fitting (questionnaire which was answered by the patient at home)

• 5. Giving out a new questionnaire and instructing the patient to answer it again right before a follow-up appointment

• 6. Setting up a date for a follow-up appointment

On a third appointment, which was after 2 months from the hearing aid fitting, the following steps were taken:

• 1. Otoscopic examination

• 2. Conversation about outcomes and patients’ reflections

• 3. Comparing scores of THI questionnaire first before and second after hearing aid fitting

• 4. Establishing a further plan for auditory rehabilitation

Statistical analysis

The sample size of this pilot study was n = 20. Due to limited patient resources available, sample size calculation was not performed and data used for analysis was raw. Parametric tests such as t-tests were used to establish the alpha levels. The alpha level used to define statistical significance was set at the p < 0.05. To perform the analyses, an Excel program was used.

Results

Figure 1 shows individual results of comparing the THI scores for the study group before and after the hearing aid fitting.

Fig. 1

Individual THI for everyone before and after hearing aid fitting

Figure 1 shows improvement in the individual THI scores after fitting in 16 out of the 20 patients included. The average THI score before the hearing aid fitting was 24 points and 16.9 after fitting—which was statistically significant. (After committing paired samples kind of t-test in Excel, p-value equaled 0.001504).

Age

When taking the age of participants into consideration, (above and below 75 years old), results in Fig. 1 show greater improvement in the THI scores in the older age group, which might be partially explained by the higher severity of HL found also in the higher age group, which is well documented in the literature [3, 4].

Figure 2 shows the results of both age groups of patients. On average, in the younger age group (patients 1 to 10), tinnitus was on the level of 20.8 points before fitting hearing aids and a level of 13.8 afterwards, with 7 points changes in clinical significance. In percentage, this equates to 33.7%. Yet the p-value after committing paired samples kind of t-test in Excel was 0.21 meaning this improvement did not reach statistical significance. The older group of patients (patients 11 to 20) had on average a slightly higher THI score, which was 27.2 points. After hearing aid fitting, it improved to 20 points, which equates to 27% change, which was statistically significant change of paired t-test (p-value equaled less than 0.005).

Fig. 2

THI before and after hearing aid fitting in both age groups

It is also worth mentioning that the elder group of patients did have on average worse hearing in comparison to the younger ones. Meaning that younger patients not only experienced less tinnitus distress but also heard better; taking these two facts into consideration, we can understand why even though their improvement was clinically significant, it was not statistically significant. In the older group, none of the patients had a mild level of hearing loss. On the moderate level, there were 8 patients, while there was 1 on severe and 1 on profound. In comparison, in the younger group, there were 3 patients with mild level of hearing loss, 7 with moderate hearing loss, and 0 with either severe or profound. These levels align with the presbyacusis progression [31].

Gender

The potential impact of gender on results was examined. It is often mentioned in the literature that tinnitus might be more common and more severe in women [3, 11, 32, 33] Our study group were 50% split between males and females. Results are shown in Fig. 3.

Fig. 3

THI before and after in both genders

Female (patients 1 to 10) THI scores on average before the fitting were 26 points, and after 22.6, an improvement of 13%. The p-value in paired t-tests for this improvement equaled 0.07 which does not reach statistical significance. Men showed an average of lower THI score, before and after hearing aid fittings. Before the hearing aid fitting, the score was 22 points, and the score was 11.2 points after the fitting, 49%; the p-value in the paired t-tests was 0.006 which was statistically significant. There can be found several explanations for why men have improved more than women. First, presbyacusis is known to affect men more than women, which means men’s hearing on average has been improved more than the women’s hearing [4]. Second of all, it is well documented in the literature that women experience more annoyance and distress caused by tinnitus. Furthermore, they also sadly score lower in proactive coping and personal resources while dealing with tinnitus [3].

Correlation between the severity of tinnitus and level of improvement after fitting

Table 1 shows the relation between pre-fitting THI scores and the clinically significant improvement after fitting.

Table 1 Number of patients on different levels of tinnitus and their improvements

It is worth noticing that there was an improvement in the THI score for most participants, regardless of the level of THI before fitting, although the more severe the starting THI score, the less improvement after fitting noticed.

Correlation between the severity of hearing loss and the improvement in the THI scores

The next examination was if the level of hearing loss showed any patterns in patients’ improvements. Table 2 presents all hearing loss levels, number of patients (n), how many of them improved in their THI scores, and how many of these improvements were clinically significant.

Table 2 Number of patients on different hearing loss levels and their improvements

Changes for the moderate hearing loss group showed statistically significant values in a paired t-test (p = 0.0044). This finding aligns with existing literature [34, 35].

THI subcategories

The Tinnitus handicap questionnaire, as mentioned earlier, consists of 25 questions, which are divided into three subcategories: functional, emotional, and catastrophic. It is strongly advised in the literature that one should only do an analysis based on the total score while considering patients’ clinical improvements [13, 21].

It does however encourage the examination of each subcategory of the THI, to understand the status of patients with tinnitus and its comorbid symptoms [13] as well as help in personalizing the rehabilitation protocols for the patient [13, 21]

In our study, there was no significant correlation between the improvement in the THI overall score and any specific subcategory score before fitting. The only observation was the high score in the question related to difficulty in sleep (question 7) that was noticed in the 4 patients who had showed no improvement in the overall score after fitting. Although the number in our pilot study is too small to draw any specific conclusion, it indicates that trouble with sleep in particular might be an important issue when looking at possible improvement gained from hearing aid fitting per se, and might need more specific intervention.

Discussion

This study is meant as a pilot study for proof of concept basis for a larger study looking at the question of improvement that can be gained for tinnitus sufferers, as a direct result of a hearing aid fitting for older patients. Our preliminary findings indicate that there might be some significant benefits for patients complaining of tinnitus, secondary to their hearing loss in this age group, as reflected by the improvement in the THI score. Although we do have to bear in mind that even though patients showed improvement, 7 of them still had their overall THI score high, which means the degree of the issue has been improved but the issue itself has not been solved.

The high incidence of presbyacusis and tinnitus having a combined effect on older patients encourages looking at common interventions that can lead to improvement in both in a holistic way and how impactable that could be on the quality of life of the patients [11].

What is more, it is vital to consider the patient’s individual factors. One size does not fit all, and even though fitting hearing aids might be a sufficient solution for some patients, there are also many others who need more assistance. Nonetheless, our preliminary findings show that hearing aid fitting can be a good first step in the rehabilitation process for patients who suffer from presbyacusis type of hearing loss and tinnitus at the same time, which aligns with the good results from the study mentioned earlier, which focused on older patients [29].

The hypothesis coming out of our pilot study is that hearing aids can improve hearing which directly impacts distress caused by tinnitus, as reflected by improvement in the THI scores within 2 months of the fitting process. This finding can be supported by the other study, with younger group of patients [28]. The improvement also seemed to have a relation with the severity of the hearing loss and the score of the THI before fitting. This finding aligns with previous research [26,27,28,29, 34,35,36].

The level of distress caused by tinnitus might also be a factor impacting patient’s outcomes. Patients with mild and moderate levels of distress were the ones who improved the most, thanks to the hearing aid fittings which can again be seen in another study with younger group of patients [28]. It is worth examining in the future the importance of having a measure of the tinnitus distress, like THI, as a factor in the rehabilitation process for older patients complaining of presbyacusis, and in the decision of fitting hearing aids, as well as the decision to refer patients for furthermore specific tinnitus management pathways, like psychologist for possible CBT (cognitive behavioral therapy). These correlations are also found in another research [37]. The relative importance of the complaint regarding sleep, being the most resistant to improvement after hearing aid fitting, is worth examining for sure, in agreement with previous research [13, 38].

Summing up, this pilot study has a few key findings which can help us better understand patients who suffer from both tinnitus and presbyacusis. These findings might help both clinicians in their everyday practice and researchers to take further steps into this area of research. The main finding addresses the pilot study question, which was as follows: Can hearing aid primarily fitted for presbyacusis help with a quality of life of tinnitus patients? The short answer is that it might, but it is very important to remember that help does not mean that tinnitus issues can be fixed by it. It means that if patients suffer from both presbyacusis and tinnitus, by improving their hearing with a hearing device, some of the tinnitus symptoms might decrease, which results in lowering of the THI scores and improving patients’ quality of life.

Study limitations and future directions

There are few limitations to this pilot study. Firstly, quality of life with tinnitus before and after hearing aid fitting was measured by the subjective tool, the THI questionnaire. Using this type of questionnaire always comes with limitations, such as biased decisions from patients; outcomes have variable consistency and sensitivity; this study was a pilot study with a limited number of patients, which also exposes it to less reliability. Time was another limitation, as patients were being tracked for only a limited period of a few months. The results provided are not meant to be blindly followed without raising any questions but may indicate some trends in the data and encourage others to pursue further research in this area.

For future studies, it could also make a difference and provide more reliable results if the patients were tracked thoroughly for a longer period, for example, if there were to be more control visits, to see if the improvement was stable or maybe improved or worsened with time.

Conclusion

Based on the results of this study, we can say that hearing aids can not only have a positive effect on the hearing of presbyacusis patients but can also decrease distress caused by tinnitus and by that improve patient’s quality of life. The patients’ outcomes may also vary in different age, gender, level of hearing loss, level of tinnitus distress, and each item of the THI groups.