Prevalence of Hearing Impairment and Hearing Complaints in Older Adults: A Study in General Practice

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1 Family Practice Oxford University Press 1993 Vol. 10, No. 4 Printed in Great Britain Prevalence of Hearing Impairment and Hearing Complaints in Older Adults: A Study in General Practice BB ABUTAN,* AW HOES,*^CL VAN DALSEN.* * J VERSCHUURE" AND A PRINS* Abutan BB, Hoes AW, Van Dalsen CL, Verschuure J and Prins A. Prevalence of hearing impairment and hearing complaints in older adults: a study in general practice. Family Practice 1993; 10: In one general practice, 660 people aged 60 years or over were screened by means of pure tone audiometry and a specific questionnaire to assess the prevalence of hearing impairment and hearing complaints. Hearing impairment was defined as an average loss of 35 db or more in the 1, 2 and 4 khz frequencies in one or both ears. In total, 37.4% (95% Cl, %) of the participants was hearing impaired. The prevalence was higher in men (55.1%) than in women (44.9%) and clearly increased with age in both sexes. The prevalence of hearing complaints in terms of hearing difficulties and/or tinnitus, was 37.3% (95% Cl, %), and increased with age, especially in women. Of the subjects with hearing impairment, 64.4% reported hearing complaints. Of the subjects without hearing impairment, 21.1% experienced hearing complaints. This study suggests that screening older adults with relatively simple methods, may identify a large proportion of men and women in general practice with hearing problems. Providing information to both patients and general practitioners about the possibilities of hearing improvement is a crucial step in making people become more aware of hearing problems. This could ultimately lead to improvement of the quality of life of older men and women with hearing problems. INTRODUCTION Hearing impairment is a common health problem in the elderly. It is estimated that in 25-60% of men and women aged 65 years or over, some type of hearing loss is present.'" 3 The most common cause of hearing impairment in the elderly is presbycusis. This is a gradually progressive bilateral sensorineural hearing loss in which the highest frequencies are affected first and the lower frequencies follow gradually. 4 This usually gives rise to communication problems and may even lead to depression and social isolation. ' * Other possible causes of hearing loss include noise exposure, use of ototoxic drugs, e.g. aminoglycosides and loop diuretics, metabolic disorders, e.g. hypothyroidism, and infections, such as herpes zoster. 5 Although hearing loss is relatively easy to diagnose in general practice, only a minority of those with hearing loss come to the attention of the genera] practitioner (CiP). 5-6 In one study, only 30% of those with complaints of hearing loss consulted their GP. 3 It is estimated that only 20% of those with a diagnosis of Departments of General Practice, * Epidemiology and Biostatistics, ' Geriatrics and * Audiology, Erasmus University Medical School, Rotterdam, The Netherlands. presbycusis are referred to a specialist. 6 The patient as well as the physician seem to consider hearing loss as an inevitable consequence of ageing and a burden one has to learn to cope with. This may partly explain the passive attitude of both the patient and the GP toward hearing impairmeni. Yet, the hearing impairment can often be improved by hearing aids or assistive listening devices. 3 Notwithstanding the possible consequences of hearing impairment in terms of communication problems and possible isolation, and the availability of methods to improve hearing loss, relatively little is known about the prevalence of hearing loss and hearing complaints in general practice. The studies that are known were performed in the UK, the USA and Canada. 5 The aim of the present study was to obtain prevalence estimates for The Netherlands of both hearing impairment and hearing complaints by studying older men and women from one general practice. SUBJECTS AND METHODS The men and women included in our study were participants in a survey in one general practice in Krimpen aan de Ijssel, a commuter suburb of Rotterdam with inhabitants. This study was part of a screening survey performed to recruit participants for a trial to 391

2 392 FAMILY PRACTICE AN INTERNATIONAL JOURNAL assess the efficacy of antihypertensive treatment in elderly hypertensives (Syst-Eur). 7 This survey included an extensive interview enquiring information about risk factors of cardiovascular diseases and the general health of the patieni, a physical examination and audiometry. All men and women aged 60 years or over and enlisted in one general practice (1179 patients) were invited to participate in the Syst-Eur survey. Of these, 163 refused to participate, 49 had died, 39 did not respond and 30 had already participated in the pilot study of the Syst-Eur trial. Another 94 persons had to be excluded on account of the exclusion criteria of the Syst-Eur survey, mainly because of dementia, liver diseases and malignancies. 7 In 144 Syst-Eur screenings, audiometry was not performed for the following reasons: they already had an hearing aid (n = 52), they were examined at home (n = 37), the examiner could not remove the cerumen or the person did not want the cerumen to be removed (n = 28), they refused the audiometry (n = 13) or a perforation of the tympanum was present (n = 3). In 11 participants the reason was unknown. Thus, audiometry was performed in 660 participants and findings in these subjects are presented in this report. In all participants the presence of hearing complaints and impairment was assessed by means of a short interview, an otoscopic examination and audiometry. The questions about hearing complaints were posed before the audiometry, as part of the interview about the general health of the participant. The participant was asked if he or she had any complaints of tinnitus and/or difficulty with hearing. The physical examination consisted of an inspection of both ears by a physician with an otoscope. Cerumen, if present, was removed. Other disorders of the ear were registered and, if necessary, treated. The hearing test was performed with a pure tone audiometer type Bosch ST20. Both ears were tested for the frequencies 0.25, 0.5, 1, 2, 3, 4, and 8 khz. The sound level was measured in steps of 5 db correctly. Hearing impairment was defined as an average loss of 35 db or more in the 1, 2 and 4 khz frequencies in one or both ears. 3 This cut-off point was chosen because at this degree of impairment it is generally recommended that the patient should be referred to a specialist, and the costs of a hearing aid are reimbursed by the health authorities in The Netherlands. Mild hearing impairment was defined as an average loss of db, moderate impairment as an average loss of db, and severe impairment as a loss of 70 db or more. 3 Presbycusis was defined according to the World Health Organization isonorm, which includes a correction for age and sex. 8 Noise-induced hearing impairment was defined as a marked dip in the audiogram, i.e. an isolated loss of one frequency. 4 RESULTS In total, 342 women and 318 men were included in the study (Table 1). The mean age was 67. Of all 660 participants, 247 (37.4%; 95% CI, 33.7^41.1 <Vb) were hearing impaired (Table 2). If those with a hearing aid were included in the numerator and the denominator, the prevalence was 42.0%. Of the subjects who were hearing impaired, 166 (67.2%) had mild, 77 (31.2%) had moderate and 4 (1.6%) had severe hearing loss. The prevalence of hearing impairment in men was 42.8% (95% CI, %) and in women 32.5% (95% CI, %). Of the persons who were hearing impaired, 20.6% (n = 51) had isolated loss in the left ear, 16.6% (n = 41) in the right ear and 62.8% (n = 155) had hearing loss in both ears. Of the 247 subjects with hearing loss, 203 participants had presbycusis defined according to the WHO isonorm. Noise-induced hearing loss was present in 25 of the 660 participants (3.8%). The prevalence of hearing impairment clearly increased with age, from 22.6% (95% CI, %) in those aged years, to 76.1% (95% CI, TABLE 1 Selected characteristics of the participants (n 660) Variable Gender Men Women Mean age (years) Health insurance Private insurance Collective insurance TABLE 2 Number % SD 6 years Prevalence of hearing impairment in older adults in general practice (n = 660) Type of hearing impairment Absolute hearing impairment (^35 db loss of 1, 2 and 4 khz) Presbycusis Noise-induced hearing impairment Other Number?o ' NB If those with a hearing aid are included in the numerator and denominator, the prevalence of hearing impairment is 42.0%.

3 HEARING IMPAIRMENT IN OLDER ADULTS %) in those aged 80 years or over. Although the prevalence of hearing impairment in men at the age of 60 years was higher than in women, the difference diminished with advancing age, and at the age of 80 years the prevalence was similar in the two sexes (Figure 1). No clear increase in the degree of hearing loss with advancing age was seen. Hearing complaints were present in 246 participants (37.3%; 95% CI, %). Of those, 80.9% expressed complaints of deafness, 11.4% had tinnitus and 7.7% experienced both deafness and tinnitus (Table 3). Although less clear than with hearing impairment, the prevalence of hearing complaints increased with age, most pronounced in women (Figure 2). Of the 247 patients who were hearing impaired, 64.4% experienced hearing complaints. Of those Hearing complaint Tinnitus 0% years years years i80 years without hearing impairment, 21.2% expressed hearing complaints. Of the persons who were hearing impaired, older men tended to express less hearing complaints than younger men. Until the age of 70 women reported less complaints than men, but beyond that age a higher proportion of the women with hearing loss reported hearing complaints than the men. The prevalence of hearing complaints was higher (71.0%) if both ears were hearing impaired than if only one ear was affected (31.3%). The prevalence of hearing complaints increased with the degree of hearing impairment (Table 4). DISCUSSION In our study of 660 elderly patients in one general practice, the prevalence of hearing impairment was 37.4% FIGURE 1 Prevalence and 95% confidence interval (I in figure) of hearing impairment by age and sex in 660 older adults in general practice. Hearing impairment was defined as an average loss of 35 db or more in the 1, 2 and 4 khz frequences in one or both ears TABLE 3 Prevalence of hearing complaints in older adults in general practice (n = 660) Number ("It of all 660 patients) "h of all 246 patients with hearing complaints 11.4 Difficulty with hearing Both tinnitus and difficulty with hearing Total (hearing complaints)

4 394 FAMILY PRACTICE AN INTERNATIONAL JOURNAL TABLE 4 Prevalence of hearing complaints by degree of hearing loss in 247 older adults with hearing impairment in general practice Degree of hearing impairment Mild (n = 166) Moderate (n = 77) Severe (n = 4) CI = confidence interval Number, %; 95% CI 93, 56.0; % 64, 83.1; % 3, 75.0; % (95% CI, %) and the prevalence of hearing complaints was 37.3% (95% CI, %). The prevalence of both hearing impairment and hearing complaints increased with advancing age, especially in women. Of those with hearing impairment, 64.4% expressed complaints whereas of those without hearing impairment as many as 21.1% reported hearing complaints. In this study the prevalence may be underestimated due to selection bias. The non-responders and the subjects excluded on the basis of the Syst-Eur exclusion criteria were older and more likely to have concomitant diseases than our study population. Furthermore, the subjects with a hearing aid were excluded because our study was aimed at finding incident cases of hearing impairment. After inclusion of these subjects in the numerator and denominator the prevalence increased to 42.0%. We tried to avoid information bias caused by the participant by asking the questions about hearing complaints (embedded in the general health interview) before the results of hearing test were known. However, some bias could have been introduced by the person performing the audiometry who may have been aware of the presence of hearing complaints of the participant. Although this may have influenced the results of the hearing test, we believe that this is unlikely to have had an important impact on the prevalence estimates. Our findings on the prevalence of hearing impairment are in accordance with the study of Davis and Thornton, 9 who reported a prevalence of 34.7%. In contrast, Herbst et a/. 2 ' 3 in a study with 253 participants, reported a prevalence of 60%. These discrepancies may be explained by the different age range and definition of hearing impairment in their study. The authors further attribute the relatively high prevalence of hearing impairment to the low socioeconomic status in their study population. The increase in the prevalence of hearing impairment with advancing age in particular in women in our study is in line with previous studies. 29 Rosenhall et at. 10 reported a prevalence of hearing complaints of persons aged 70 years or over, of almost 50% which is similar to the prevalence in our study. In their study, however, men reported hearing complaints more often than women, while the prevalence of hearing complaints in our study was similar in both sexes. It may be expected that the prevalence of hearing complaints would increase with the degree of hearing impairment, In our study, years years years *80 years FIGURE 2 Prevalence and 95% confidence interval (I in figure) of hearing complaints, i.e. hearing difficulties and/or tinnitus, by age and sex in 660 older adults in general practice

5 as in the London/Wales study, the prevalence of hearing problems increased from mild (56.0%) to moderate (83.1%) hearing impairment, but was lower for severe hearing impairment (75.0%). 3 This might be explained by the small number of subjects who are severely hearing impaired, leading to imprecise estimates, which is illustrated by the wide confidence interval. The relatively high prevalence (21.1%) of hearing complaints in participants without hearing impairment may partly be attributed to our definition of hearing impairment. In The Netherlands, the CMR (continuous morbidity registration), a longitudinal survey in four general practices, reported that 105/1000 patients aged years will consult their GP because of hearing impairment." In light of the results of the present study, this would mean that about two-thirds of those with hearing impairment do not consult their family physician. Our study illustrates that more patients are hearing impaired and have hearing complaints than are known to the GP. Thus, screening the elderly for hearing impairment by means of relatively simple methods such as audiometry and a questionnaire, as well as providing information about hearing rehabilitation to both patient and physician, may be useful to make the physician and the patient become more aware of hearing problems. In view of the modern advances in technology regarding hearing improvement, this may ultimately lead to a reduction in the number of older adults with hearing problems and to an improvement in their quality of life. HEARING IMPAIRMENT IN OLDER ADULTS 395 REFERENCES 1 Sangster JF, Gerace M, Seewald RC. Hearing loss in elderly patients in a family practice. Can Med Assoc J 1991; 2144: Gilhome Herbst KR, Humphrey C. Hearing impairment and mental state in the elderly living at home. Br Med J 1980; 281: Gilhome Herbst KR, Meredith R, Stephens SDG. Implications of hearing impairment for elderly people in London and Wales. Ada Otolaryngol 1991; Suppl. 476: Sataloff J. Hearing loss. Philadelphia and Toronto: J.B. Lippincott Company, 1966; Weinstein BE. Geriatric hearing loss: myths, realities, resources for physicians. Geriatrics 1989; 44: 42-48, 58,60. 6 Voorn Th B. Gehoorstoornissen bij oudere mensen. Huisarts Wet 1985; 26 (Suppl. H4P): Amery A, Birkenhager W, Bulpitt CJ, et at. Syst-Eur. A multicentre trial on the treatment of isolated systolic hypertension in the elderly: objectives, protocol, and organization. Ageing 1991; 3: International Organization for Standardization ISO/DIS Davis A, Thornton R. The impact of age on hearing impairment: some epidemiological evidence. Proceedings of 14th Donavox Symposium, Donavox Jubilee Foundation, Copenhagen 1990; (ISBN ). 10 Rosenhall U, Pedersen K, Moller MB. Self-assessment of hearing problems in an elderly population. A longitudinal study. Scand Audiol 1987; 28: " Lamberts H, Urbanus NAM. Gehoorstoornissen in Nederland: Episode-georitnteerde epidemiologische gegevens. Ned Tijdschr Geneeskd 1987; 131: 692-6%.