«THE ECONOMIC IMPACT AND COST OF HEARING LOSS IN AUSTRALIA A report by Access Economics Pty Ltd February 2006 Listen Hear! The economic impact and ...»
Table 3-2 reports studies of hearing loss among children by degree of loss.
Some studies report mild and moderate hearing loss together. The reported rate in the mild-to-moderate cohort is approximately 60% of hearing loss cases. The United Kingdom study (Fortnum et al, 2001) and the earlier Australian study (Upfold and Ipsey, 1982) report moderate hearing loss as 59% of the cohort. The American study (Stredler Brown, 2003) reports mild hearing loss as 30% and moderate as a further 30% of the total. The Australian Hearing data report a lower rate of severe and profound loss (25%:75% rather than 40%:60%). The rate for mild losses is very high in this Australian cohort. However, all children reported in this group have received a device of some sort, even if this is an FM system. The data also include assessments of Aboriginal children where otitis media is a significant problem as well as children with unilateral hearing loss.
Figure 3-1 shows the increasing prevalence of hearing loss in Australian children by age. Gender based data were not available. Similarly the data were not segmented by worse or better ear but were supplied on the basis that the child had been fitted with a hearing device or aid.
The prevalence rates by year of age as reported by Australian Hearing were applied to population data to generate an overall prevalence of 10,268 children in 2005 aged less than 15 years, 2.5/1,000 in this age group, which is broadly consistent with the studies in Table 3-1. The Australian Hearing (2005) data were also considered to be the most reliable to estimate the severity proportions in the Australian child population currently (proportionately allocating unknowns across each sub-group) as 36.7% mild, 38.3% moderate, 13.3% severe, and 11.7% profound. Figure 3-2 depicts the prevalence of hearing loss in children aged less than 15 years in 2005, while the detailed numbers are provided in the tables in Section 3.4
1,500 1,000 701 665 616 585 500
Figure 3-3 presents prevalence rates in the worse ear for adult (over 15 years) hearing loss by age group.
Overall prevalence rates are 26.3% for males 15 years and over, 17.1% for females 15 years and over and 21.6% for the adult population.
This equates to more than one in every four men and more than one in every five Australian adults who have hearing loss.
When applying these rates to the Australian population, there are an estimated 3,534,963 adults (people 15 years and over) in Australia with hearing loss.
60% of Australian adults with hearing loss are male, with the gender differences attributed to differing levels of workplace noise exposure.
Approximately half are in the working age population (aged 15-64 years).
37% of adults with hearing loss are aged over 70 and, within this age group, 74% have hearing loss.
Two thirds of people aged over 60, and 88% of men over 70, have hearing loss in the worse ear.
66% had a mild loss, 23% had a moderate loss and 11% had a severe or profound hearing loss.
This is somewhat similar to the Beaver Dam Study where the proportions of hearing loss were reported as 58.1% mild, 30.6% moderate and 11.3% marked (Cruickshanks et al, 1998).
Wilson et al (1998) report that hearing loss in the population is predominantly sensori-neural in nature with a prevalence of 20.2% compared with prevalence rates for conductive (0.4%) and mixed hearing loss (1.6%).
Wilson also reports that hearing loss is also predominantly bilateral in nature with a prevalence of 20.3% versus 6.3% for unilateral losses at the 21dB threshold level in the worse ear.
Detailed data tables are provided in Section 3.4.
PREVALENCE OF ADULT HEARING DISABILITY IN THE BETTER EAR3.3.2 Prevalence rates of adult hearing loss for the better ear, referred to by Wilson as hearing disability, are illustrated in Figure 3-4.
FIGURE 3-4: PREVALENCE RATES, HEARING LOSS, ADULTS (BETTER EAR)
Naturally overall rates of disability from hearing loss are lower than those reported for impairment – 16.0% of adults aged 15 and over have hearing loss in the better ear compared to 21.6% who have hearing loss in the worse ear.
Consistently hearing disability is more common in males across all age groups.
Hearing loss becomes quite apparent in the community aged over 60 years.
Using measures of the better ear, 12.9% of the population has treatable hearing loss ( 25 db) and approximately 2.1% experience considerable disability with losses of 45 db or worse (Wilson, 1997: 92).
Detailed data tables are provided in Section 3.4.
In 2005, there were an estimated 3.55 million Australians with hearing loss (worse ear). Figure 3-5 highlights the increasing prevalence rates with age.
800,000 600,000 400,000 200,000
Of these 10,268 were children aged up to 14 years (0.29% of the total) and 3,534,963 were adults 15 and over.
49.5% were of working age (15–64 years) 64% of people with hearing loss were aged over 60 years with 37% aged 70 years or more Overall 59.9% (2,125,162) were males and 40.1% (1,420,069) were females with hearing loss predominantly affecting males to 60 years with the female rate catching up in the older years.
Figure 3-6 shows that hearing loss is predominantly mild in nature, although one third (34%) of people with hearing loss experience a loss that is moderate or worse.
Using measures of the better ear, there were 2,626,364 people with hearing loss causing disability, with 62% of these being male.
COMPARISON WITH NATIONAL HEALTH PRIORITIES3.4.2 Figure 3-7 provides a comparison of the prevalence of hearing loss (worse ear) with the national health priority areas, showing it to be more prevalent than all national health priorities except musculoskeletal conditions.
FIGURE 3-7: PREVALENCE, HEARING LOSS AND NATIONAL HEALTH PRIORITIES, 2001
3.5 ESTIMATES OF THE DEAF COMMUNITYThe concept of the Australian Deaf Community refers to people who are either born (severely to profoundly) deaf to Deaf families who use Auslan (Australian Sign Language) or people born with hearing loss into families where the parents hear, but who learn sign language. As Johnston (2004:358) observes: “(I)t is only children with an early and profound hearing loss, who are likely to be lifelong sign language users”.
Johnston also observes that there have been a number of studies that have attempted to estimate the size of the Australian Deaf Community, or on the basis of which estimates have been attempted. Estimates derived from enrolments in Deaf Schools and community data collection methods vary between 6,500 individuals and 15,000 individuals. As this study focuses on costs associated with hearing loss using confirmed costs where available, the indeterminate size of the Deaf Community was not a specific barrier to this study. However, an estimate is required for the burden of disease analysis (Chapter 6), where the estimate used was 10,000 people, the midpoint number from a variety of studies seeking to estimate the size of this Community (Johnston, 2004).
Table 3-7 projects hearing loss in children by severity. These projections are a function of population growth and so, unlike the adult population, these numbers remain fairly static over time. The number of children with hearing loss is projected to increase from 10,268 in 2005 to 11,031 by mid-century, an increase of only 7.4% over the period.
As can be seen in Figure 3-8 below, hearing loss is expected to remain more common in boys in the coming years, although the differences between genders is small in real terms.
FIGURE 3-8: PROJECTED PREVALENCE OF CHILD HEARING LOSS BY GENDER5,800
Table 3-8 reports the projected prevalence of hearing loss (worse ear) in the adult population, on the basis of demographic ageing only (ie not taking into account possible changes in age-gender prevalence rates in the future, which may increase or decrease depending on noise and other exposures, technology and policy changes).
In the absence of a substantive prevention program, the severity of prevalent hearing loss is not expected to change much (mild hearing loss remains at 66%, moderate at 23% and severe at 11% of the total).
Figure 3-9 depicts the growth in hearing loss by gender.
The prevalence of hearing loss increases from 21.0% to 31.5% of all males.
The prevalence of hearing loss increases from 13.9% to 21.9% of all females and the female share of total hearing loss increases fractionally from 40% to 41%.
The prevalence of hearing loss in the worse ear is expected to more than double by 2050 (a 2.2-fold increase).
The prevalence of hearing loss in the better ear – hearing disability – is expected to increase more than 80% by 2030 and nearly 2.4-fold by 2050.
Table 3-9 reports the projected prevalence of hearing loss (worse ear) in the total population. Table 3-10 reports the projected prevalence of hearing loss (better ear) in the total population.
4. HEALTH SYSTEM COSTS 4.1 METHODOLOGY Estimates for direct health system costs are derived in Australia by the Australian Institute for Health and Welfare (AIHW) from an extensive process developed in collaboration with the National Centre for Health Program Evaluation for the Disease Costs and Impact Study (DCIS). The approach measures health services utilisation and expenditure (private and public) for specific diseases and disease groups in Australia. The DCIS methodology has been gradually refined over the 1990s to now estimate a range of direct health costs from hospital morbidity data, case mix data, Bettering the Evaluation and Care of Health (BEACH) data, the National Health Survey and other sources. AIHW (2005) provides a summary of the main results of estimates of health expenditure by disease and injury for the year 2000-01. The advantage of topdown methodology is that cost estimates for various diseases will be consistent, enhancing comparisons and ensuring that the sum of the parts does not exceed the whole (total health expenditure in Australia).
The health expenditure costs reported for hearing loss include categories H90 and H91 from the International Classification of Disease Tenth Revision (ICD-10) and exclude procedures and treatments for otitis media, which is classified as a respiratory condition. Although otitis media can lead to hearing loss, to include it would overstate health system expenditure. The recurrent AIHW health system costs also do not encompass aids and devices such as cochlear implants or hearing aids, but would include implant surgery and associated in-patient hospital stays.
The AIHW include only 86% of total recurrent health expenditure in their estimates of expenditure by disease and injury, referred to as ‘allocated’ health expenditure. The ‘unallocated’ remainder includes capital expenditures, expenditure on community health (excluding mental health), public health programs (except cancer screening), health administration and health aids and appliances. However, in the case of hearing loss, it is evident that the cost of hearing aids and cochlear implants is much greater than the average cost of aids and appliances relative to recurrent spending across all diseases, so to factor up the recurrent spending by 100%/86% would understate the cost of such devices. In this study, the factoring up is undertaken to cover the cost of the unallocated capital, community health, public health programs and health administration, while the aids and devices are separately estimated in Section 4.4.
The AIHW recurrent allocated data for 2000-01 were used as the base for Access Economics’ estimates for health expenditure on hearing loss in 2005. Two factors
contributed to the extrapolation:
health cost inflation (AIHW, 2005) measured 3.7% over 2000-01 to 2001-02, 4.1% over 2001-02 to 2002-03 and 3.8% over 2002-03 to 2003-04. For the 18 months from 2003-04 to the end of calendar year 2005, health cost inflation is assumed to have averaged 3.2%, which was the average rate over the period in 1997-98 to 2002-03. Thus overall inflation resulted in a 17.5% increase over the whole period from 2000-01 to end-2005; and estimated growth in prevalence of hearing loss 2000-01 to end 2005, derived from ABS demographic data and the Australian Hearing and Wilson prevalence rate data for each age-gender group.
Figure 4-1 shows health expenditure by type of health cost for people with hearing loss.
The majority (53%) of health expenditure is directed to services provided by ‘other’ (ie, allied health or non-medical) health professionals – $130.2 million in
2005. This item would include audiology and speech therapy services.
Outpatient expenditures were the second largest, comprising a further 19% or $45.7 million and would encompass ear examinations, advanced assessments of ear disease and procedures that can be performed in the out patient setting such as the removal of wax.
Expenditure on medical specialists was the third most substantial cost element at $32.9 million (13% of the total).
Expenditure was of similar order of magnitude (3.5% to 5.3% of the total) for inpatient costs ($8.8 million) – covering small numbers of surgeries to correct ossicular problems and perforations of the ear drum, implant surgeries (but not the devices)and other forms of ear surgery and treatment – as it was for health research ($10.2 million), and pharmaceuticals, the vast majority of which are over-the-counter medications ($13.2 million).