The role of audiometry in the prevention of occupational deafness

The research set out to test three main hypotheses derived from a summary of literature relevant to the use of audiometry in industry. These hypotheses were: (1) performing audiometry increases the probability that hearing protectors, once issued, will be worn; (2) audiometry is considered by workers to be evidence of their employer's concern for their welfare; (3) audiometry is associated with common law claims by workers against employers for alleged occupational deafness. Six subsidiary hypotheses were also developed. Four methods of data collection were used: (1) attitude questionnaires were administered to samples of workers drawn from an industrial company performing audiometry and two industrial companies not performing audiometry; (2) a postal questionnaire was sent out to industrial medical officers; (3) surveys were undertaken to assess the proportion of the workforce in each of eight industrial companies that was wearing personal hearing protectors that had been provided; (4) structured interviews were carried out with relevant management level personnel in each of five industrial companies. Factor analysis was the main statistical analytic technique used. The data supported all three main hypotheses. Audiometry was also examined as an example of medical screening procedure. It was argued that the validation of medical screening procedures requires the satisfaction of attitudinal or motivational validation criteria in addition to the biological and economic criteria currently used. It was concluded that industrial audiometry failed to satisfy such attitudinal or motivational criteria and so should not be part of a programme of screening for occupational deafness. It was also concluded that industrial audiometry may be useful in creating awareness, amongst workers, of occupational deafness. It was argued that the only profitable approach to investigating the role of audiometry in preventing occupational deafness is to study the attitudes and perceptions of everyone involved.

An evaluation of certain aspects of an occupational health service

This thesis has been concerned with obtaining evidence to explore the proposition that the provision of occupational health services as arranged at the present time represents a misallocation of resources. The research has been undertaken within the occupational health service of a large Midlands food factory. As the research progressed it became evident that questions were being raised about the nature and scope of occupational health as well as the contribution, in combating danger at work, that occupational health services can make to the health and safety team. These questions have been scrutinized in depth, as they are clearly important, and a resolution of the problem of the definition of occupational health has been proposed. I have taken the approach of attempting to identify specific objectives or benefits of occupational health activities so that it is possible to assess how far these objectives are being achieved. I have looked at three aspects of occupational health; audiometry, physiotherapy and pre-employment medical examinations as these activities embody crucial concepts which are common to all activities in an occupational health programme. A three category classification of occupational health activities is proposed such that the three activities provide examples within each category. These are called personnel therapy, personnel input screening and personnel throughput screening. I conclude that I have not shown audiometry to be cost-effective. My observations of the physiotherapy service lead me to support the suggestion that there is a decline in sickness absence rates due to physiotherapy in industry. With pre-employment medical examinations I have shown that the service is product safety oriented and that benefits are extremely difficult to identify. In regard to the three services studied, in the one factory investigated, and because of the immeasurability of certain activities, I find support for the proposition that the mix of occupational health services as provided at the present time represents a misallocation of resources.

Prevalence and risk factors for reduced sound tolerance (hyperacusis) in children

OBJECTIVE: To estimate the prevalence of reduced sound tolerance (hyperacusis) in a UK population of 11-year-old children and examine the association of early life and auditory risk factors with report of hyperacusis. DESIGN: A prospective UK population-based study. STUDY SAMPLE: A total of 7097 eleven-year-old children within the Avon longitudinal study of parents and children (ALSPAC) were asked about sound tolerance; hearing and middle-ear function was measured using audiometry, otoacoustic emissions, and tympanometry. Information on neonatal risk factors and socioeconomic factors were obtained through parental questionnaires. RESULTS: 3.7% (95% CI 3.25, 4.14) children reported hyperacusis. Hyperacusis report was less likely in females (adj OR 0.64, 95% CI 0.49, 0.85), and was more likely with higher maternal education level (adj OR 1.72, 95% CI 1.08, 2.72) and with readmission to hospital in first four weeks (adj OR 1.98, 95% CI 1.20, 3.25). Report of hyperacusis was associated with larger amplitude otoacoustic emissions but with no other auditory factors. CONCLUSIONS: The prevalence of hyperacusis in the population of 11-year-old UK children is estimated to be 3.7%. It is more common in boys.

Functional outcomes in the Cleft Care UK study - Part 3:oral health and audiology

OBJECTIVES: To compare oral health and hearing outcomes from the Clinical Standards Advisory Group (CSAG, 1998) and the Cleft Care UK (CCUK, 2013) studies. SETTING AND SAMPLE POPULATION: Two UK-based cross-sectional studies of 5-year-olds born with non-syndromic unilateral cleft lip and palate undertaken 15 years apart. CSAG children were treated in a dispersed model of care with low-volume operators. CCUK children were treated in a centralized, high volume operator system. MATERIALS AND METHODS: Oral health data were collected using a standardized proforma. Hearing was assessed using pure tone audiometry and middle ear status by otoscopy and tympanometry. ENT and hearing history were collected from medical notes and parental report. RESULTS: Oral health was assessed in 264 of 268 children (98.5%). The mean dmft was 2.3, 48% were caries free, and 44.7% had untreated caries. There was no evidence this had changed since the CSAG survey. Oral hygiene was generally good, 96% were enrolled with a dentist. Audiology was assessed in 227 of 268 children (84.7%). Forty-three per cent of children received at least one set of grommets--a 17.6% reduction compared to CSAG. Abnormal middle ear status was apparent in 50.7% of children. There was no change in hearing levels, but more children with hearing loss were managed with hearing aids. CONCLUSIONS: Outcomes for dental caries and hearing were no better in CCUK than in CSAG, although there was reduced use of grommets and increased use of hearing aids. The service specifications and recommendations should be scrutinized and implemented.

Association of SNPs in LCP1 and CTIF with hearing in 11 year old children:findings from the Avon Longitudinal Study of Parents and Children (ALSPAC) birth cohort and the G-EAR consortium

BACKGROUND: The genetic basis of hearing loss in humans is relatively poorly understood. In recent years, experimental approaches including laboratory studies of early onset hearing loss in inbred mouse strains, or proteomic analyses of hair cells or hair bundles, have suggested new candidate molecules involved in hearing function. However, the relevance of these genes/gene products to hearing function in humans remains unknown. We investigated whether single nucleotide polymorphisms (SNPs) in the human orthologues of genes of interest arising from the above-mentioned studies correlate with hearing function in children. METHODS: 577 SNPs from 13 genes were each analysed by linear regression against averaged high (3, 4 and 8 kHz) or low frequency (0.5, 1 and 2 kHz) audiometry data from 4970 children in the Avon Longitudinal Study of Parents and Children (ALSPAC) birth-cohort at age eleven years. Genes found to contain SNPs with low p-values were then investigated in 3417 adults in the G-EAR study of hearing. RESULTS: Genotypic data were available in ALSPAC for a total of 577 SNPs from 13 genes of interest. Two SNPs approached sample-wide significance (pre-specified at p = 0.00014): rs12959910 in CBP80/20-dependent translation initiation factor (CTIF) for averaged high frequency hearing (p = 0.00079, β = 0.61 dB per minor allele); and rs10492452 in L-plastin (LCP1) for averaged low frequency hearing (p = 0.00056, β = 0.45 dB). For low frequencies, rs9567638 in LCP1 also enhanced hearing in females (p = 0.0011, β = -1.76 dB; males p = 0.23, β = 0.61 dB, likelihood-ratio test p = 0.006). SNPs in LCP1 and CTIF were then examined against low and high frequency hearing data for adults in G-EAR. Although the ALSPAC results were not replicated, a SNP in LCP1, rs17601960, is in strong LD with rs9967638, and was associated with enhanced low frequency hearing in adult females in G-EAR (p = 0.00084). CONCLUSIONS: There was evidence to suggest that multiple SNPs in CTIF may contribute a small detrimental effect to hearing, and that a sex-specific locus in LCP1 is protective of hearing. No individual SNPs reached sample-wide significance in both ALSPAC and G-EAR. This is the first report of a possible association between LCP1 and hearing function.