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Abstract
Objectives Occupational skin diseases (OSDs) pose significant risks to the health and well-being of restaurant workers. However, there is presently limited evidence on the burden and determinants of OSDs among this occupational group. This research aims to estimate the prevalence and associated factors of suspected OSDs among restaurant workers in Peninsular Malaysia.
Design A secondary data analysis of the 2023 Registry of Occupational Disease Screening (RODS) was performed. The RODS survey tool, which included the Nordic Occupational Skin Questionnaire, a symptoms checklist and items on work-relatedness, was used to screen for OSDs. Logistic regression analyses were performed to identify associated factors.
Setting and participants Restaurant workers (n=300) registered in RODS from February 2023 to April 2023, aged 18 years and above and working in restaurants across Selangor, Melaka and Pahang for more than 1 year, were included in the study, whereas workers who had pre-existing skin diseases were excluded.
Results The prevalence of suspected OSDs among study participants was 12.3%. Higher odds of suspected OSDs among study participants were observed among those exposed to wet work (adjusted OR (AOR) 22.74, 95% CI 9.63 to 53.68) and moderate to high job stress levels (AOR 4.33, 95% CI 1.80 to 10.43).
Conclusions These findings suggest that OSDs are a significant occupational health problem among restaurant workers. Interventions targeting job content and wet work may be vital in reducing OSDs among this group of workers.
- occupational & industrial medicine
- occupational dermatology
- public health
- preventive medicine
- prevalence
- risk factors
Data availability statement
Data may be obtained from a third party and are not publicly available. The data that support the findings of this study are available from Universiti Teknologi MARA (UiTM) but restrictions apply to the availability of these data, which were used under license for the current study, and therefore are not publicly available. The data are however available from the authors upon reasonable request and with the permission of UiTM.
This is an open access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited, appropriate credit is given, any changes made indicated, and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/.
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- occupational & industrial medicine
- occupational dermatology
- public health
- preventive medicine
- prevalence
- risk factors
STRENGTHS AND LIMITATIONS OF THIS STUDY
A priori sample size analysis was performed to ensure that the study was sufficiently powered to detect significant associations.
Validated study instruments and multivariate regression analyses were used to improve the validity of the study findings.
Dermatological assessments and diagnostic procedures such as the patch test are necessary to confirm a diagnosis of occupational skin diseases.
The cross-sectional study design does not permit inferences to be made regarding causality.
Data may be constrained in terms of generalisability to restaurant workers in East Malaysia and other countries due to possible differences in the work environment.
Introduction
Occupational skin diseases (OSDs), defined as any changes in the skin, mucosa and associated structures that are directly or indirectly triggered, affected, maintained or worsened by agents found within the occupational setting or work environment,1 are a significant workplace health and safety concern. The International Labour Organisation identifies four main categories of OSDs, including irritant contact dermatitis (ICD), allergic contact dermatitis (ACD), contact urticaria, occupational vitiligo and other skin diseases caused by agents at work.2
In the USA, OSDs are the second most commonly reported illness, accounting for approximately 19% of all occupational diseases.3 However, this figure is likely an underestimation due to underreporting of the illness, not only in the USA but elsewhere in the world.4 This may be due to limitations in reporting, such as accessibility and complexity of notification systems, as well as attending physicians’ poor recognition of its association with the workplace.5
One of the occupational cohorts at particular risk of developing OSDs is restaurant workers. This occupational group faces specific risk factors, such as frequent hand washing and exposure to irritants and allergens, contributing to the development of OSDs.6 7 Studies conducted in Ireland, France, Poland, Singapore and Iran have highlighted the prevalence of OSDs among restaurant workers, which ranges from 7.5% to 40%.6–10 The high prevalence of OSDs poses significant risks to the health and well-being of restaurant workers, as OSDs have been shown to lead to discomfort, pain, psychological distress, impaired quality of life and financial strain among affected individuals, as well as impacting their work performance and interpersonal relationships.11 12
Unfortunately, there is presently limited evidence on OSDs among restaurant workers working in Asia.13 Given that the restaurant industry has experienced substantial growth in recent years, with a notable increase in the number of individuals employed in this sector,14 studies to shed light on the occurrence of OSDs among restaurant workers in Asia are warranted. Moreover, its relationship with work factors, particularly those amenable to modifications such as job stress and occupational safety and health training, is unknown. A greater understanding of the burden and determinants of OSDs among restaurant workers would be instrumental in developing targeted preventive measures in order to reduce the occurrences of OSDs among this group of workers. With this in mind, the objective of this study is to examine the prevalence and associated factors of OSDs among restaurant workers in Peninsular Malaysia.
Methods
Study design and population
This is a secondary data analysis of restaurant workers identified from the Registry for Occupational Disease Screening (RODS) database 2023, a programme under the Faculty of Medicine, University Teknologi MARA, developed to screen for occupational disease in major sectors in Peninsular Malaysia. Participants in the programme were recruited through convenience sampling of workers from multiple companies across different industries in Peninsular Malaysia, including restaurants, hotels, manufacturing, construction, utilities, retail and wholesale trade, fishery, forestry, agriculture, mining and quarrying industries. Participant recruitment for the RODS programme was voluntary, with workers being contacted and invited to participate through a combination of direct outreach and coordination with the management of companies that had agreed to participate in the RODS programme.
According to the Department of Statistics Malaysia (2017), there were approximately 891 616 workers working in restaurants in Malaysia. For this study, restaurant workers registered in RODS from February 2023 to April 2023, aged 18 years and above and working in restaurants across the three states of Selangor, Melaka and Pahang for more than 1 year were included. Workers who have pre-existing skin diseases were excluded from the study. A priori sample size calculation via the Open Epi software package V.3.01 indicated that the minimum sample size based on: (1) 15% OSDs prevalence,8 5% margin of error, 80% power of the study and 95% confidence level and (2) Odds Ratio (OR) of risk factors from previous studies,6 14 80% power of the study, 95% confidence level and a 1:1 ratio of exposed to unexposed samples, was 236. Universal sampling was performed to select participants for this study. The study flowchart is illustrated in figure 1.
Study flowchart. RODS, Registry for Occupational Disease Screening.
Patient and public involvement
Patients or the public were not involved in the design, or conduct, or reporting, or dissemination plans of this research.
Instruments and study variables
Data for the RODS database 2023 were collected using the RODS survey tool, which was developed to screen for six occupational diseases: occupational mental illness, occupational neurotoxicity disorder, occupational noise-induced hearing loss, occupational respiratory disorder, OSD and work-related musculoskeletal disorders. It comprises seven sections and 60 variables in total, including sections on personal information, employment information, personal protective equipment practices, safe work practices, workplace environment, symptoms of disease and work-relatedness. The RODS survey tool included single-item measures for assessing sociodemographic, occupational and organisational factors, work-relatedness, as well as the Nordic Occupational Skin Questionnaire (NOSQ) and the Job Stress Level Inventory (JSLI) to screen for OSDs and measure job stress levels, respectively. It was constructed in Malay and has undergone back-to-back translation, content and face validation by a 10-member expert panel, including one public health specialist, two occupational health physicians, three occupational safety and health personnel, one language expert and three questionnaire experts. Additionally, pilot testing was conducted among 21 restaurant workers to further verify the tool’s feasibility. Data collection for the RODS database was conducted by the RODS research team using a self-administered questionnaire.
The dependent variable, suspected OSDs, was examined using the self-reported hand and forearm eczema question set (items D1–D12) of the NOSQ,15 a symptom checklist for OSDs that can be used to screen for OSDs with high sensitivity,16 as well as items on work-relatedness.17 Workers were considered to have suspected OSDs if they either have a self-reported diagnosis of eczema based on the NOSQ or if they experienced one or more OSDs symptoms persistently for more than 3 weeks within the past 12 months, with at least one positive work-related item. The independent variables were: (1) individual factors including age, gender, smoking, education level, race and atopy, (2) occupational factors including types of occupation, duration of employment, working hours, frequency of handwashing, exposure to wet work, exposure to hot and cold environments, and job stress level, as well as (3) organisational factors including the usage of personal protective equipment (PPE) and Occupational Safety and Health (OSH) training. Smoking was defined as smoking any tobacco product daily or occasionally, whereas non-smoking was defined as never smoked or stopped smoking for more than 6 months.18 Atopy was defined as having the genetic tendency to develop allergic diseases, either by reporting positively on the ‘allergic’, ‘allergic rhinitis’ or ‘asthma’ items in the RODS survey tool.19 Wet work was defined as having wet hands or wearing gloves for 2 hours or more per day.20 The frequency of handwashing in this study was categorised into ‘0–5 times a day’, ‘6–10 times a day’, ‘11–20 times a day’ and ‘more than 20 times a day’, in keeping with the subcategorisation used by previous studies, where the frequency of 0–5 times, 6–10 times, 11–20 times and more than 20 times was considered low, moderate, high and very high frequency, respectively.15 21 Working hours were classified into ‘less than 8 hours’, ‘8–12 hours’ and ‘more than 12 hours’, in keeping with previous literature.22 Exposure to cold environment was defined as working in areas with air temperature below 10°C, while exposure to hot environment was defined as working in areas with air temperature above 30°C.23 Job stress was determined by the total scores from the 20-item JSLI, with scores of 17–39, 40–61 and 62–85 categorised as low, moderate and high levels of job stress, respectively.24 Finally, OSH training referred to safety and health-related training participants received in the workplace.25
Statistical analysis
All analyses were performed using the IBM Statistical Package for the Social Sciences, software V.28.0. Data cleaning was performed; as there was no missing data, all data were analysed. Descriptive statistics were performed and presented as mean and SD for continuous variables or frequencies and percentages for categorical variables. The prevalence of suspected OSDs among study participants was calculated. To determine the factors of suspected OSDs, simple logistic regression was conducted to estimate the crude association between factors and suspected OSDs. All significant variables with a p value of 0.25 or less identified from the univariate analysis were entered into the multiple logistic regression model to estimate adjusted associations. A p value of less than 0.05 was considered statistically significant. Model checking, interaction term, multicollinearity and model fit were also assessed. The interaction term was examined by multiplying the predictor variables before entering them into the regression model, with a p value of less than 0.05 indicating that there was an interaction between the two variables.26 Multicollinearity was assessed using the variance inflation factor (VIF), with a VIF of less than 10 considered to indicate no multicollinearity.27 Finally, model fit was assessed using the Hosmer-Lemeshow goodness-of-fit test, with a p value of more than 0.05 indicating a good fit.28
Results
A total of 300 restaurant workers registered in RODS working in restaurants across Selangor, Melaka and Pahang were included. The individual, occupational, and organisational characteristics of study participants are outlined in table 1.
Individual, occupational, and organisational characteristics of study participants (n=300)
Individual characteristics of study participants
The mean age of the study population was 30.4 years (SD 8.5). The largest proportion of study participants were male (61.7%) and of Malay ethnicity (41.3%). In terms of education, the vast majority had secondary level education and below (60.3%). Most study participants (75.3%) were not atopic and non-smokers (69.3%).
Occupational characteristics of study participants
The occupation with the highest representation was Waiter’ (39.0%), followed by ‘Kitchen Staff’ (33.7%). More than half of study participants (57.0%) had been employed for 1–5 years. A significant majority (80.6%) of study participants worked 8–12 hours per day. Most of the study participants washed their hands 0–20 times daily (67.3%) and were involved in wet work (83%). While 73.3% of study participants reported working in cold environments, only 17.0% worked in hot environments. Most of the study participants (60.0%) reported low levels of job stress.
Organisational characteristics of study participants
Most (81.0%) study participants received OSH training before starting work. 59.8% and 49.6% of study participants reported wearing face masks and gloves, respectively, every time at the workplace.
Prevalence of suspected OSDs among study participants
The prevalence of suspected OSDs among restaurant workers in Peninsular Malaysia is 12.3% (95% CI 9% to 16.4%).
Associated factors of suspected OSDs among study participants
Factors found to be statistically significant at p value of 0.25 during simple logistic regression analysis include atopy, job category, working hours, frequency of handwashing, involvement in wet work, job stress level and exposure to a hot environment (table 2). After adjusting for confounders, two factors were significantly associated with suspected OSDs among restaurant workers (table 3). The factors were wet work (adjusted OR (AOR) 22.74, 95% CI 9.63 to 53.68) and moderate to high job stress level (AOR 4.33, 95% CI 1.80 to 10.43).
Crude associations of individual, occupational, and organisational factors with suspected OSDs (n=300)
Adjusted associations of individual, occupational and organisational factors with suspected OSDs (n=300)
Discussion
The main objective of this study was to examine the prevalence and associated factors of suspected OSDs among restaurant workers. Based on a universal sample of restaurant workers (n=300) working across restaurants in Selangor, Melaka and Pahang, the prevalence of suspected OSDs among restaurant workers was 12.3%. After adjustment for confounding factors, factors associated with increased odds of suspected OSDs include wet work and moderate to high levels of job stress.
The prevalence of suspected OSDs observed in this study is in keeping with the prevalence reported by previous studies, which ranged from 8.4% to 15%. A study conducted among Singaporean workers working in restaurants, catering and fast-food outlets demonstrated that the prevalence of contact dermatitis was 10%.7 Similarly, the prevalence of occupational dermatitis among Iranian food service industry workers was observed to be 8.4%,6 whereas 9.4% of Indian highway restaurant workers were reported to have skin-related symptoms.29 Meanwhile, 10.3% of French employees in the food service industry were documented to have skin pathologies9 and the prevalence of OSDs, including ICD, ACD and protein contact urticaria, in the UK catering industry was estimated to be 15%.30 The high prevalence of OSDs observed among workers of the food service industry across the globe could be due to numerous factors, including exposure to chemicals in food and cleaning agents, irritants and allergens in food products, as well as a lack of awareness of workplace safety and health practices in the culinary sector.31
In this study, wet work was determined to be a significant predictor of suspected OSDs among restaurant workers. Numerous studies have consistently indicated wet work as a risk factor for the development of hand eczema,32–34 supporting our findings. This may be because prolonged exposure to water can disrupt the stratum corneum, the skin’s natural protective barrier, which plays an essential part in retaining moisture and preventing the penetration of irritants and allergens into the skin.35 Moreover, continuous wet work can lead to the elimination of natural oils and lipids from the skin, resulting in dryness and increased permeability, which makes the skin more vulnerable to irritants.36 Indeed, wet work was one of the most commonly reported agents for contact dermatitis among food service industry workers in Ireland37 as well as Singapore.7
Job stress was also shown to be a predictor of suspected OSDs among restaurant workers. This is in keeping with previous studies, which have demonstrated a significant relationship between job stress and the occurrence of occupational dermatoses among workers.38–40 A study among Italian workers in the healthcare sector has demonstrated a strong relationship between work stress and skin complaints.40 Similarly, a high workload was also perceived among Swedish video display terminal workers reporting skin symptoms.41 In this regard, the presence of stress may have notable effects on various physiological aspects, including immunity, the skin barrier and cutaneous inflammation.42–44 This then contributes to flares of inflammatory dermatoses among workers. Indeed, evidence from previous studies suggests that psychological stress exacerbates contact dermatitis,45 impacts allergic contact sensitisation46 and influences more than 30% of dermatological disorders.39 While these arguments underscore how job stress can significantly influence the development of OSDs, the relationship between job stress and OSDs has been suggested to be bidirectional. Previous studies have shown that individuals with skin disease have a triple risk of reporting moderate to high stress, which has been suggested to be due to concerns with body image, shame, depression and the impedance of occupational activities.47 48
There were several non-significant findings in this study, including atopy and frequent handwashing, which have been shown to contribute to the development of OSDs among workers.7 Atopy, a genetic predisposition to allergic conditions,49 was hypothesised to increase the risk of developing skin diseases in an occupational setting.1 However, the non-significant association between atopy and suspected OSDs observed in this study is consistent with the findings of previous studies that reported similar findings,50 51 which may suggest that other factors such as direct skin contact with allergens or irritants specific to the restaurant industry may play a more significant role in the development of OSDs among restaurant workers.52
In relation to handwashing, the non-significant findings observed in this study are also in keeping with the findings of several studies.51 53 A study conducted among bakery workers in the UK found that while handwashing more than 20 times per day increases the risk of skin symptoms, it does not significantly contribute to the development of OSDs.51 Similarly, another study showed that frequent handwashing was not significantly associated with self-reported skin disorders among a sample of Bruneian healthcare workers.53 This suggests that handwashing frequency alone may not be the sole determinant of OSD occurrence among restaurant workers and that additional factors, such as soap selection and moisturisation, are crucial for maintaining skin health in occupational settings.52
There are some limitations to this study. First, due to its cross-sectional design, a causal relationship between the identified factors and OSDs cannot be established. Second, the study analysis relied on data retrieved from a registry, which is subject to the availability and completeness of the parameters recorded in the database. Nevertheless, this was not an issue in this study. Third, the self-administered questionnaire used in the RODS database introduces the possibility of participant recall bias and social desirability bias. However, measures were taken to minimise this by checking data for consistency and contacting participants to clarify inconsistent entries, as well as ensuring study confidentiality to participants. Fourth, it is important to note that the tools used in this study do not provide a definitive diagnosis of OSDs. A dermatological assessment and diagnostic procedures such as the patch test are necessary to confirm the diagnosis. Finally, the study findings may be constrained in terms of generalisability to restaurant workers in East Malaysia and other countries due to possible differences in the work environment.
Equally, there are some strengths to this study. First, to the best of the authors’ knowledge, this is the first study to investigate OSDs among restaurant workers in Malaysia. This provides valuable insights into a previously understudied population and contributes to the existing literature on OSDs. Second, several measures were undertaken to increase the robustness of the study findings. This includes a priori sample size analysis to ensure that the study is sufficiently powered to detect significant associations, using tools that have been validated, and employing regression analyses to control for potential confounders.
Conclusions
In conclusion, at least 1 in 10 Malaysian restaurant workers may develop OSDs, and it continues to be a persistent problem in the service industry despite the availability of preventive measures.54 To mitigate this occupational health problem, policymakers and restaurant operators can implement targeted measures to protect their workers against exposure to known risk factors, including wet work and job stress. This includes giving education to restaurant operators on the risk of OSDs among workers, implementing job rotation for workers involved in wet work and developing PPE programmes and stress management programmes in the workplace. Future studies should incorporate dermatological assessment and confirmatory diagnostic tests to confirm OSDs as well as longitudinal study designs that can establish cause-and-effect relations. Ultimately, a greater appreciation of the burden of OSDs and their predictors would enable the development of further remedial actions that can help promote a healthier and safer working environment for workers in the restaurant industry.
Data availability statement
Data may be obtained from a third party and are not publicly available. The data that support the findings of this study are available from Universiti Teknologi MARA (UiTM) but restrictions apply to the availability of these data, which were used under license for the current study, and therefore are not publicly available. The data are however available from the authors upon reasonable request and with the permission of UiTM.
Ethics statements
Patient consent for publication
Ethics approval
The study was given ethical approval by the University of Technology MARA (UiTM) research ethics board committee (reference code: (REC/03/2023 ST/MR/70)). Permission for data retrieval was obtained from the RODS database owner (Faculty of Medicine, UiTM). A letter of non-disclosure agreement between the researchers and the RODS database owner was signed, dated 16 May 2023. Informed consent was retrieved from participants prior to enrolment in RODS.
Acknowledgments
We would like to thank the RODS database main research and data collection team, and Department of Safety and Health Malaysia for their contributions to this project.
References
Footnotes
Contributors All authors (MHAF, EZS, SMY, NI, MM, KM, MRA, KG, II, AE, KMT, ASM, AFAN and AFAH) made contributions to this study, whether during the conceptualising of the study, study design, data collection, data analysis and interpretation. MHAF wrote the first draft of the article, and EZS, SMY, NI, MM and KM critically reviewed the article. All authors (MHAF, EZS, SMY, NI, MM, KM, MRA, KG, II, AE, KMT, ASM, AFAN, and AFAH) read and approved the final manuscript. SMY is the guarantor of this study.
Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
Competing interests None declared.
Patient and public involvement Patients and/or the public were not involved in the design, or conduct, or reporting, or dissemination plans of this research.
Provenance and peer review Not commissioned; externally peer reviewed.