Costs and effectiveness of hearing conservation programs at 14 US metal manufacturing facilities.

OBJECTIVE: This study characterised overall and specific costs associated with hearing conservation programmes (HCPs) at US metal manufacturing sites, and examined the association between these costs and several noise-induced hearing loss (NIHL) outcomes. DESIGN: We interviewed personnel and reviewed records at participating facilities. We also measured noise for comparison to the ten-year average of measurements made by each facility. NIHL outcomes assessed included rates of standard threshold shifts (STS) and high-frequency hearing loss, as well as prevalence of hearing impairment, for each participating facility. We used linear regression to identify per-person HCP costs that best predicted the NIHL outcomes. STUDY SAMPLE: We evaluated 14 US metal manufacturing facilities operated by a single company. RESULTS: Annual HCP costs ranged from roughly $67,000 to $397,000 (average $308 ± 80 per worker). Our full-shift noise measurements (mean 83.1 dBA) showed good agreement with the facilities' measurements (mean 82.6 dBA). Hearing impairment prevalence was about 15% overall. Higher expenditures for training and hearing protector fit-testing were significantly associated with reduced STS prevalence. Higher training expenditures were also related to lower hearing impairment prevalence and high-frequency hearing loss rates. CONCLUSIONS: HCP costs were substantial and variable. Increased workplace spending on training and fit-testing may help minimise NIHL.

Cost-Effective Hearing Conservation: Regulatory and Research Priorities.

Hearing conservation programs (HCPs) mandated by the US Occupational Safety and Health Administration (OSHA) cost about $350/worker/year. Are they cost-effective? A cross-sectional model of the US adult population with and without HCPs incorporates (1) the American Medical Association's method for estimating binaural hearing impairment and whole-person impairment; (2) the model of the International Organization for Standardization (ISO) for estimating both age-related and noise-induced hearing loss; and (3) an acceptable cost of $50,000 per quality-adjusted life year. The ISO model's outputs were audiometric thresholds for groups of people with different age, sex, and noise exposure history. These thresholds were used to estimate cost per quality-adjusted life year saved for people in HCPs with different noise exposure levels. Model simulations suggest that HCPs may be cost-effective only when time-weighted average (TWA) noise exposures are ≥ 90 dBA. Enforcing existing regulations, requiring engineering noise control at high exposure levels, and using new methods that can document hearing protection device performance could improve cost-effectiveness. If the OSHA action level remains at 85 dBA-TWA, reducing the permissible exposure limit to the same level would simplify management and slightly improve cost-effectiveness. Research should evaluate employer compliance across industries, determine whether workers currently excluded from HCP regulations are at risk of noise-induced hearing loss, and develop cost-effective HCPs for mobile workers in construction, agriculture, and oil and gas drilling and servicing. Research on HCP cost-effectiveness could be extended to incorporate sensitivity analyses of the effects of a wider range of assumptions.

Speech perception in medico-legal assessment of hearing disabilities.

OBJECTIVE: Examination of Danish data for medico-legal compensations regarding hearing disabilities. The study purposes are: (1) to investigate whether discrimination scores (DSs) relate to patients' subjective experience of their hearing and communication ability (the latter referring to audio-visual perception), (2) to compare DSs from different discrimination tests (auditory/audio-visual perception and without/with noise), and (3) to relate different handicap measures in the scaling used for compensation purposes in Denmark. DESIGN: Data from a 15 year period (1999-2014) were collected and analysed. STUDY SAMPLE: The data set includes 466 patients, from which 50 were omitted due to suspicion of having exaggerated their hearing disabilities. RESULTS: The DSs relate well to the patients' subjective experience of their speech perception ability. By comparing DSs for different test setups it was found that adding noise entails a relatively more difficult listening condition than removing visual cues. The hearing and communication handicap degrees were found to agree, whereas the measured handicap degrees tended to be higher than the self-assessed handicap degrees. CONCLUSIONS: The DSs can be used to assess patients' hearing and communication abilities. The difference in the obtained handicap degrees emphasizes the importance of collecting self-assessed as well as measured handicap degrees.

Economic Burden of Hearing Loss for the U.S. Military: A Proposed Framework for Estimation.

The goal of this multiphased research is to develop methods to comprehensively determine the economic impact of hearing impairment and noise-induced hearing injury among active duty U.S. Service Members. Several steps were undertaken to develop a framework and model for economic burden analysis: (1) a literature review identifying studies reporting the cost of health conditions and injuries in the Department of Defense, (2) consultation with a panel of subject matter experts who reviewed these cost items, and (3) discussions with DoD data stewards and review of relevant data dictionaries and databases. A Markov model was developed to represent the cumulative economic effect of events along the career span, such as retraining after hearing impairment and injury, by synthesizing inputs from various sources. The model, as developed and proposed in this study, will be a valuable decision-making tool for the DoD to identify high-risk groups, take proactive measures, and develop focused education, customized equipping, and return-to-duty and reintegration programs, thereby maximizing the retention of skilled, experienced, and mission-ready Service Members.

The Department of Defense Epidemiologic and Economic Burden of Hearing Loss study.

Although studies have examined the relation between military-related noise and hearing, comprehensive data to calculate rates of hearing loss across all Services and to determine economic impact are lacking. The goal of the multiphase Department of Defense (DoD) Epidemiologic and Economic Burden of Hearing Loss (DEEBoHL) project is to examine rates of hearing impairment and noise-induced hearing injury, relevant noise exposures, and to determine the economic burden of these outcomes to the DoD and Service Members. The DoD Hearing Center of Excellence is supporting the following Phase I specific aims, among active duty Service Members to (1) calculate rates of hearing impairment and noise-induced hearing injury, and (2) develop a framework for the DoD to conduct comprehensive economic burden studies for hearing impairment and noise-induced hearing injury. The study is led by a multidisciplinary team from The University of Texas School of Public Health, The University of Texas Health Science Center at San Antonio, and The Geneva Foundation, with guidance from experts who make up the study advisory board. In this article, we focus on an overview of the DEEBoHL study, the methods for the first aim of this effort, and describe future plans for the study.

A business case evaluation of workplace engineering noise control: a net-cost model.

OBJECTIVE: This article provides a convenient tool for companies to determine the costs and benefits of alternative interventions to prevent noise-induced hearing loss (NIHL). METHODS: Contextualized for Singapore and in collaboration with Singapore's Ministry of Manpower, the Net-Cost model evaluates costs of intervention for equipment and labor, avoided costs of productivity losses and medical care, and productivity gains from the employer's economic perspective. RESULTS: To pilot this approach, four case studies are presented, with varying degrees of economic benefits to the employer, including one in which multifactor productivity is the main driver. CONCLUSION: Although compliance agencies may not require economic analysis of NIHL, given scarce resources in a market-driven economy, this tool enables stakeholders to understand and compare the costs and benefits of NIHL interventions comprehensively and helps in determining risk management strategies.

High frequency hearing sensitivity in adolescent females of a lower socioeconomic status over a period of 24 years (1985-2008).

PURPOSE: To examine annually over a period of 24 years, the high frequency hearing sensitivity in different groups of urban female adolescents with a low socioeconomic status (SES) and residential foster care. METHODS: Hearing screening (15 decibel [dB] hearing level ranging from 1,000 to 8,000 Hertz [Hz]) and threshold (>15 dB hearing level) records were obtained from 8,710 female adolescents (mean age, 15.8 years [range, 12-20 years]), predominantly Hispanic and African American from households with a low SES. Data related to the use of personal listening devices (PLDs), daily hours of usage, occurrence of tinnitus, and hearing thresholds between 1,000 and 8,000 Hz over an 8-year period (2001-2008) were obtained from the adolescents. RESULTS: High frequency hearing loss (HFHL) doubled over the 24-year period from 10.1% in 1985 to 19.2% in 2008. In comparison with the general adolescent population, this group of female adolescents presented with a higher percentage of bilateral mild or greater degrees of HFHL at two or more frequencies including 3,000, 4,000, and 6,000 Hz. Use of PLDs increased four-fold, from 18.3% (n = 68) in 2001 to 76.4% (n = 227) in 2008. Of the total number reporting tinnitus (n = 286), 99.7% (n = 285) also reported regular PLD use. A significant relationship was found between PLD use and reported tinnitus and HFHL irrespective of time of use of PLD. CONCLUSIONS: Increased incidence of HFHL, reported tinnitus, PLD use, and hours of daily use in at-risk female adolescents of a low SES was found. A frequency interval of 3,000-6,000 Hz should be included in hearing screening protocols to identify potentially disabling hearing loss. Hearing conservation strategies need to be developed and/or modified that target and reach at-risk children and adolescents.

Modeling the Unites States government's economic cost of noise-induced hearing loss for a military population.

OBJECTIVE: The purpose of this paper is to demonstrate the feasibility and utility of developing economic cost models for noise-induced hearing loss (NIHL). First, we outline an economic model of NIHL for a population of US Navy sailors with an "industrial"-type noise exposure. Next, we describe the effect on NIHL-related cost of varying the two central model inputs--the noise-exposure level and the duration of exposure. Such an analysis can help prioritize promising areas, to which limited resources to reduce NIHL-related costs should be devoted. METHODS: NIHL-related costs borne by the US government were computed on a yearly basis using a finite element approach that took into account varying levels of susceptibility to NIHL. Predicted hearing thresholds for the population were computed with ANSI S3.44-1996 and then used as the basis for the calculation of NIHL-related costs. Annual and cumulative costs were tracked. Noise-exposure level and duration were systematically varied to determine their effects on the expected lifetime NIHL-related cost of a specific US Navy sailor population. RESULTS: Our nominal noise-exposure case [93 dB(A) for six years] yielded a total expected lifetime cost of US $13,472 per sailor, with plausible lower and upper bounds of US $2,500 and US $26,000. Starting with the nominal case, a decrease of 50% in exposure level or duration would yield cost savings of approximately 23% and 19%, respectively. We concluded that a reduction in noise level would be more somewhat more cost-effective than the same percentage reduction in years of exposure. CONCLUSION: Our economic cost model can be used to estimate the changes in NIHL-related costs that would result from changes in noise-exposure level and/or duration for a single military population. Although the model is limited at present, suggestions are provided for adapting it to civilian populations.

Hearing loss in veterans and the need for hearing loss prevention programs.

Currently, there are more than 445,000 veterans receiving compensation for hearing loss associated with military service, and 395,000 receiving compensation for service-related tinnitus. In addition to compensation payments, service-related hearing disorders cost the US Department of Veterans Affairs in terms of provision of hearing aids, hearing aid-related services, and clinical services at its 220 facilities nationwide. It is imperative that hearing conservation among military personnel and veterans be addressed. In this paper, we describe the rationale for and the development of a multimedia Hearing Loss Prevention Program aimed at preventing the progression of hearing loss among veterans associated with social, recreational, and nonmilitary occupational noise exposure. The program was developed based on the principles outlined in the Health Belief Model of Rosenstock (1966) and the Health Promotion Model of Pender et al. (2002).

Estimation of equivalent noise exposure level using hearing threshold levels of a population.

OBJECTIVES: Noise-induced hearing loss (NIHL) is costly in both human and economic terms. One means of reducing NIHL is to apply engineering controls to hazardous noise sources. To trade off the cost of engineering controls against the total direct monetary costs incurred by NIHL, a means of predicting the amount of NIHL that will be incurred over the life-cycle of a hazardous noise source is necessary. A widely known algorithm for the prediction of NIHL is published in ANSI S3.44-1996. However, the algorithm inputs, noise exposure level and duration, may be difficult to determine in some cases. This paper describes the conceptual basis of an approach for using ANSI S3.44-1996 to predict hearing thresholds in a population even when noise exposure levels and durations are not precisely known, and demonstrates the initial application of this approach to a single military population. DESIGN: Retrospective data were obtained on the hearing-threshold levels, demographic characteristics, and noise exposure history of 250 male U.S. Navy machinists' mates. A maximum-likelihood fitting procedure was developed in which the noise level input to the algorithm was varied in order to determine the noise level that best accounted for all of the data. RESULTS: The maximum likelihood fitting produced a value for the noise level input of approximately 93 dBA, with a standard error of approximately 0.3. The low standard error virtually eliminates any estimate above 94 or below 92 dBA, and indicates that a good fit to the data was achieved. CONCLUSIONS: This research demonstrates the feasibility of calibrating the algorithm to an individual population, even when noise exposure level or duration is not precisely known. Future work will focus on validating and generalizing this approach so that it may be used to predict hearing-threshold levels in various populations. Such an approach may be used in calculating potential cost savings in compensable hearing loss due to the application of noise control solutions.

Complying with a corporate global noise health surveillance procedure--do the benefits outweigh the costs?

The purpose of this study was to determine whether the benefits of early identification of work-related noise-induced hearing loss outweigh the costs of complying with a Global Noise Medical Surveillance Procedure of a large corporation. Hearing is fundamental to language, communication, and socialization. Its loss is a common cause of disability, affecting an estimated 20 to 40 million individuals in the United States (Daniell et al., 1998). NIOSH reported that approximately 30 million U.S. workers are exposed to noise on the job and that noise-induced hearing loss is one of the most common occupational diseases. It is irreversible (NIOSH, 2004). The average cost of a noise-induced hearing loss is reported to range from dollars 4,726 to dollars 25,500. Corporate history indicates a range of dollars 44 to dollars 20,157 per case. During this 4-year study in one plant, the average annual cost of complying with the Global Noise Medical Surveillance Procedure was dollars 19,509 to screen an average of 390 employees, or dollars 50 per worker. The study identified 11 non-work-related standard threshold shifts. All cases were referred for appropriate early intervention. Given the results, this hearing health program is considered beneficial to the corporation for both work- and non-work-related reasons.

[Noise-induced hearing loss--factors affecting worker's decision to submit a disability claim].

Noise-induced hearing loss is recognized worldwide as a prevalent work-related morbidity and is the most common compensated occupational disease in Israel. Despite extended legislation, hearing conservation programs, surveillance and biological monitoring (by audiometry) of work sites and workers, the burden of this injury remains high. As a rule, afflicted workers refrain from filing compensation claims and do so only at later stages when both subjective and objective evidence of advanced hearing loss is present. We have evaluated the determinants that seem to influence the decision of an individual worker to file a claim. We found that the major determinants are subjective perception of the level of hearing disability and clinical symptoms such as: tinnitus (OR = 3.3 with CI 95% = 2.1 5.2), verbal communication disturbances (OR = 2.7, 95% CI = 1.9-3.8), complaints of dizziness (OR = 1.9, 95% CI = 1.4-2.5), severity of hearing impairment (by audiometry with OR = 1.04, 955 CI = 1.02-1.06) and musculoskeletal complaints (OR = 1.6, 95% CI = 1.2-2.2). These findings attest to the relatively late stage in the development of noise-induced hearing loss at which workers file a claim for compensation and rehabilitation. In order to alleviate the burden of this injury in the future and encourage workers to approach the National Insurance Institute at an earlier stage, we suggest several ways of intervention and improving the awareness of all parties concerned.

Outcomes analysis for hearing conservation programs.

In health care, an increasing interest in accountability for outcomes, proof of quality care, and cost effectiveness is forcing many practitioners, including audiologists, in the direction of using outcomes analysis to provide proof of performance in their practices. Critical to the conduct of outcomes analysis are the selection of valid outcomes metrics and application of appropriate statistical processes. Modeling of clinical protocols is a useful exercise for developing outcomes data and data management standards. The authors describe the implications for wider use of outcomes modeling once the Health Insurance Portability and Accountability Act (HIPAA) administrative simplification law is implemented. This legislation will set up a wholly new administrative data set that has strong potential to provide outcomes metrics to a variety of Audiology practices. The modeling exercise described here was originally intended to derive assessment outcomes for evaluating hearing conservation program effectiveness in military populations from an administrative database implemented within the Military Health System starting in 1997. The outcomes modelers, however, soon realized the broader applicability of modeling techniques for other special populations and Audiology practices, particularly with the oncoming startup of HIPAA legislative mandates. The modeling exercise demonstrates a process of structuring standard health-care codes to produce outcomes data for epidemiologic and cost analyses, thereby providing better information to guide health-care practices toward improving quality and cost effectiveness. This information in time series should also provide a record of continuous quality improvement. The authors present a general hearing surveillance protocol for evaluating occupational hearing loss. The protocol is used as a specific instance to demonstrate the shaping of an outcomes metrics model. This same process can be applied more generally when used to model outcomes data from other audiology practices. Implementation of the administrative data model described here began at more than 400 Department of Defense (DOD) medical treatment facilities worldwide as of October 1, 1999. The exercise of developing similar outcomes metrics for newborn hearing screening programs, school hearing conservation programs, and other clinical and rehabilitative audiology practices in the civilian sector remains to be done.

Occupational hearing loss in Washington state, 1984-1991: II. Morbidity and associated costs.

This study examined 4,547 workers' compensation claims accepted for hearing-related conditions in Washington state between 1984 and 1991; 80% resulted in disability compensation (n = 3,660). Acute hearing-related conditions comprised 11% of accepted conditions (95% confidence interval [CI], 2-15%); most claims were for chronic noise-related hearing loss. Tinnitus was reported in 64% of accepted claims (95% CI, 54-75%). The median binaural-equivalent hearing loss in compensated claims was 12.5% (inter-quartile interval, 5-22%; 90th percentile, 34%), although it declined by 30% during the study period. The number of claims and associated impairment increased with claimant age, but the number of claims dropped dramatically after age 65. Annual total disability settlements almost tripled in 8 years, totaling $22.8 million. This study indicates that occupational hearing-related conditions: 1) are manifested by mild to moderate hearing loss, accompanied by tinnitus in a majority of cases; 2) may be under-recognized in older, formerly noise-exposed individuals; and 3) were associated with substantial increases in compensation and medical costs over time, through 1991.

Exaggerated hearing loss in noise induced hearing loss compensation claims in Victoria.

OBJECTIVE: To determine the incidence of exaggerated hearing loss in people claiming workers compensation for noise induced hearing loss, as well as the ability of a range of testers to detect this exaggeration. SUBJECTS: 333 people who claimed compensation for noise induced hearing loss between 13 September 1993 and 31 July 1994 in Victoria and who had undergone two independent subjective hearing tests. METHOD: The hearing test results and referral decisions made by testers were examined in the light of the results of a single objective hearing test (cortical evoked response audiometry). RESULTS: The incidence of exaggerated hearing loss was 17.7%. Testers performing the first subjective hearing test detected only 2.2% of claimants who exaggerated. The audiologist performing the second subjective test detected 94.2% of claimants who exaggerated. CONCLUSIONS: The high incidence of exaggerated hearing loss and the large difference in ability to detect this exaggeration by the two groups of testers demonstrate the need for appropriate test procedures to be followed and a second hearing test to be reintroduced. Without accurate testing, there will be overpayment for noise induced hearing loss claims.