Concept Paper Presentation Title: Prevalence of Suspected Occupational Noise-Induced Hearing Loss among workers in Manufacturing Industry and Its Associated Factors in Klang Valley, Malaysia

Concept Paper Presentation Title: Prevalence of Suspected Occupational Noise-Induced Hearing Loss among workers in Manufacturing Industry and Its Associated Factors in Klang Valley, Malaysia.

Content. Background Study Problem Statement and Rationale Conceptual Framework Research Objectives Methodology Flowchart of Study Study Significant/Applied value of research Reference.

Background Study. Definition : Noise-Induced Hearing Loss – sensory deafness caused by long-term exposure of the auditory system to a noisy environment (Ding T et al., 2019) Worldwide, 16% of disabling hearing loss in adults is attributed to occupational noise. (Nelson DI et al., 2005) A summary of NIHL prevalence studies in Asia ranging from 17% to 89%, varies among multiple industries and sectors ( Fuente A et al., 2011) Currently, Malaysia's manufacturing sector serves as the primary driver of the country's economic growth, making a considerable contribution to exports, GDP, and the creation of jobs at various skill levels ( Ngu et al., 2020) However, this recognition has led to problems with occupational safety and health (OSH) among workers. More workers were susceptible to noise-induced hearing loss (NIHL) ..

Background. 4. ;uidelines on Management of Occupational Noise -Related Hearing Disorders 10,000 8,000 6,000 4,000 2,000 o 7173 2197 147 2013 5366 2047 3377 1563 2014 2015 Case reported 3474 2016 4201 2479 2017 confirmed 6372 3907 2018 8997 5699 2019.

Background. STATISTIK JENIS PENYAKIT DAN KERACUNAN *EKERJAAN YANG DISAHKAN TAHUN 2021 STATISTIK KEMAL ANGAN DAN PENYAKIT PEKERJAAN NEGARA TAHUN 2021 ooo 3648 Kes 1,350 Kes mt Kes Gargguan Elen Gansn•ann Pekee)aan 3' Kes Kidd O 2 Kes Lain•LaVJ Powak.'t 10 Kes 43 Kes Koeæunan Pokedaan 2 Kes Penyakit Pwu•fbru Po«riaan Powakit Elon O f Kes nser O f Kes m.kosczia/.

Problem Statement and Rationale. 24% of hearing difficulty among U.S. workers is caused by occupational exposures. ( Occupational Hearing Loss (OHL) Surveillance | NIOSH | CDC , n.d.) In Malaysia, 3648 workers were reported to have hearing disorders which contribute to only 0.02% of the total working population in Malaysia. ( Official Website Department of Occupational Safety and Health - MAIN , n.d.) This shows that under-reporting of occupational diseases and poisonings including NIHL is still an issue in Malaysia. ( Official Website Department of Occupational Safety and Health - MAIN , n.d.) There is also a substantial gap between the number of cases notified to DOSH with the number of cases confirmed after DOSH’S investigations. Few studies have given inconsistent finding such as tinnitus which is weakly associated with NIHL ( Pelegrin A.C et al., 2015) while it is highly associated in another study (Kim KS et al., 2010). The same goes for other factors such as noise exposure, work duration, and also smoking. Therefore this study is to determine the prevalence and find more significant associated factors of suspected NIHL as part of the early detection and prevention of occupational health disease. This study will not focusing on confirmed cases of NIHL as no pure tone audiometry measurement will be done..

Individual Factor Age Gender Nationality Marital Status Medical History Occupational Factor Nature of work Duration of Employment Duration of Work Type of Hazard Exposed at Work Social/Organizational Factor Workplace Environment Training by employer Access to Information on Occupational Safety at work Education Level Medication History Smoking Alcohol Genetics Shift/Non Shift Compliance to PPE Chemical Exposure Workplace Practice.

Research Objectives. General Objectives: To determine the prevalence and associated factors of Occupational Noise-Induced Hearing Loss among manufacturing workers in Klang Valley, Malaysia Specific Objectives : To determine the prevalence of suspected Occupational Noise-Induced Hearing Loss among manufacturing workers in the Klang Valley, Malaysia To determine association between individual factors, occupational factors, and organizational factors with suspected Occupational Noise-Induced Hearing Loss among manufacturing workers in Klang Valley, Malaysia To determine factors associated with suspected NIHL with regards to individual factors, occupational factors, and organizational factors among manufacturing workers in Klang Valley, Malaysia.

Research Methodology. No Method Element Methodology 1. Study Design Cross-sectional study 2. Study Duration 1 st October 2022 until 30th September 2023 3. Target Population All workers in manufacturing industries in Malaysia 4. Study Population All workers in manufacturing Industries in Klang Valley Malaysia 5. Sampling Frame List of all workers in manufacturing industries in Klang Valley Malaysia 6. Inclusion Age : Workers in manufacturing sector in Klang Valley > 18 years old Working duration : At least 12 months Able to understand Malay Able to access questionnaire (Google form) from mobile phone/computer/laptop/tab 7. Exclusion Diagnosed with any hearing related medical condition Sustained injury that would affect hearing Contract workers.

No Method Element Methodology 8. Sampling Method Multistage Stratified Random Sampling Method 9. Sample Size 363 The sample size was determined based on study by Sam W.Y et al (2017) who found the prevalence of NIHL among small and medium enterprise workers in Selangor was 73.3%. By using a single population proportion formula of 0.73 with margin of error of 0.05, Z score for 95% confidence interval (CI) of 1.96, and 20% of attrition rate, the final sample was 363 (Wayne W., 2022) 10 Data Collection Method Self administered questionnaire 12. Data Analysis and Statistical test Frequency and Percentage Mean, SD Univariate Analysis (Chi Square Test) Binary logistic Regression.

Research Tool. Self-administered questionnaire in Malay Language Validated English versions of questionnaires were used. Consist of 7 sections : Personal Information Employment Information Personal Protection Equipment Compliance Workplace Practice Symptoms of Occupational Disease Working Environment Exacerbating Factor Translation and validation will be conducted by the main research team.

Validated Research Tools (English Version). 12. Criteria Development and validation of a screening questionnaire for noise-induced hearing loss (Rosso et al., 2011) Validation of a questionnaire to identify hearing loss among farm operators (McCullagh., 2012) Questions Likert Scale Part 1 : 17 questions consist of demographic data, occupational history, hobbies and leisure, general medical history and aural medical history Part 2 : 28 questions consist of 5 domains : High Tone : 4 questions Social Situation : 12 questions Family Situation : 5 questions Personal Attitude : 5 questions Noise Exposure : 2 questions Yes-No questions 10 Questions altogether Three or more positive responses qualify a failure Data Analysis Hearing scores were determined by the sum of the points accumulated in Part 2 of the questionnaire Data Analysis : Chi-Square Test Spearman’s rank correlation coeffificient Mean and SD The agreement between each questionnaire item and the audiogram results for each of the three frequency levels was compared using the Kappa statistic ROC curves were used to examine the sensitivity and specificity of the NIDCD hearing questionnaire relative to the “gold standard” of the audiometric examinations;.

13. Criteria Development and validation of a screening questionnaire for noise-induced hearing loss (Rosso et al., 2011) Validation of a questionnaire to identify hearing loss among farm operators (McCullagh., 2012) Results Two hundred and fifty workers from three companies (two printing and one woodworking) participated in this study. The sensitivity of the hearing loss questionnaire in detecting noise-induced hearing loss was 32%, while its specificity was 79%. There was an evidence to suggest good agreement (r =0.523) between the total number of years worked in noisy jobs and NIHL (P <0.05). The mean number of positive responses to items was 4.64 ( SD = 2.93). Using the NICDC pass/fail criteria, over 70% of the sample failed, responding affirmatively to three or more items. Receiver–operator characteristic curves, measuring the ability of the questionnaire to correctly classify those with and without the disease suggested that the level of performance of the questionnaire as a whole, ranged from 0.74 to 0.69 (fair to poor) Sensitivity 32% 80-89% Specificity 79% 37-43%.

14. Approval Approval from the Department and Ethics Presentation.

Study Significance, Applied Value of Research. Workers Early detection hence early prevention, referral, and medical intervention of workers with suspected NIHL. Organization Reduce the amount of absenteeism, early retirement, and stress-related illness hence increasing productivity Reduce the financial and economic burden of the organization Occupational Practice Improving in compliance with good occupational practice especially in using PPE and adherence to SOP/guidelines of safe work procedure Body of Knowledge Identifying new risk factors for NIHL Appropriate measures, national policy-making and new guidelines in future Planning and strengthening prevention programmes in other industries.

References. https://www.cdc.gov/niosh/topics/ohl/default.html Ding, T., Yan, A., & Liu, K. (2019). What is noise-induced hearing loss?. British Journal of Hospital Medicine , 80 (9), 525-529. Occupational Hearing Loss (OHL) Surveillance | NIOSH | CDC . (n.d.). https://www.cdc.gov/niosh/topics/ohl/default.html Nelson, D. I., Nelson, R. Y., Concha‐Barrientos, M., & Fingerhut, M. (2005). The global burden of occupational noise‐induced hearing loss. American journal of industrial medicine , 48 (6), 446-458. Fuente, A., & Hickson, L. (2011). Noise-induced hearing loss in Asia. International journal of audiology , 50 (sup1), S3-S10. Pelegrin , A. C., Canuet , L., Rodríguez, Á. A., & Morales, M. P. (2015). Predictive factors of occupational noise-induced hearing loss in Spanish workers: A prospective study. Noise & health , 17 (78), 343–349. https://doi.org/10.4103/1463-1741.165064 . Kim K. S. (2010). Occupational hearing loss in Korea. Journal of Korean medical science , 25 (Suppl), S62–S69. https://doi.org/10.3346/jkms.2010.25.S.S62.

17. Thank you.

Problem Statement and Rationale. In Malaysia, nearly 70% of occupational diseases are reported as Occupational Noise Induced Hearing Loss (ONIHL) (DOSH Guideline, 2021). However, it is difficult to identify exactly how many workers are affected and at risk with NIHL since there are very limited published data in this country. The under-reporting of occupational diseases and poisonings including NIHL is still an issue in Malaysia.(DOSH) Few studies have identified associated factors for NIHL such as smoking and duration of employment. More studies are needed to strengthen the findings and find more significant associative factors of hearing loss.( Rasasoran DR et al, 2021 ) Lack of awareness, knowledge, and skills among OHDs in associating exposure to hazards in workplace also contributes to difficulty in early screening of noise hazards hence the under-reporting of potential NIHL. ( Roze AM et al, 2021) Therefore this study is to determine the prevalence and the associated factors of NIHL as part of the early detection and prevention of occupational health disease..

Approximately 18% of all Manufacturing workers have hearing difficulty https://www.cdc.gov/niosh/topics/ohl/default.html The comparison shows the prevalence of occupational diseases reported in the reviewed studies among the population of workers in various industries are higher than the statistical prevalence of occupational diseases and poisoning for workers in Malaysia based on data from the Department of Occupational Safety and Health (DOSH), Malaysia and workers' compensation insurance from Social Security Organization (SOCSO) The latest data from DOSH shows an increase in notification for NIHL (3,377 cases).