Differences in risk for gastric cancer exist among occupations and industries in Japan. Using a 2015 national dataset, we estimated the mortality rates due to gastric cancer in Japanese male and female workers aged 25–64 years. Regression models were used to estimate the mortality rate ratios separately for men and women with adjustment for age. The occupation with the highest risk ratio was “Service” in men (2.06, 95% confidence interval: 1.63–2.61) and “Construction and Mining” in women compared with “Sales”. For industries, workers in “Mining”, “Electricity, Gas, Heat supply and Water”, “Fisheries”, “Agriculture and Forestry”, and “Construction” had a higher mortality risk. Our results showed that occupations and industries with higher mortality rates in men had the same trend as the results from 2010, and occupations and industries with higher mortality rates in women were almost the same as those in men. The analyses also indicated that managerial and professional workers in Japan had higher mortality as opposed to developed Western countries. In conclusion, this study suggests that occupations and industries still impact men and women’s health in terms of mortality due to gastric cancer in Japan.
The aim of this study was to identify effective work place intervention strategies for the prevention of low back pain (LBP). The study focused on interventions to two major groups: personal interventions and technical interventions. Data basis were searched for with inclusion criteria: study design based on randomised controlled trial; outcome measures including non-specific LBP occurrence expressed by prevalence or intensity; intervention met the definition of the technical and/or personal (physical exercises, behavioural training, educational) intervention programme. Eighteen papers were selected for full analysis. The diversification of quantitative indicators of differences between control and intervention groups were carried out using Cohen’s d index. The results of analysis showed strong differences in effects among intervention strategies, as well as among different cases within similar intervention strategies. LBP severity before intervention and the length of intervention were discussed as potentially influencing factors. The results of the analysis suggest that the most effective strategies for LBP prevention include technical modifications of the workstand and education based on practical training. Behavioural and physical training seems to be of lesser importance. LBP severity before intervention and the time when the measurements of outcome measures take place play an important role in the effectiveness of intervention.
This study evaluated the performance of two respirators, a replaceable particulate respirator (RPR) and a powered air-purifying respirator (PAPR), worn according to non-recommended methods. Ten subjects wore either an RPR or PAPR according to the recommended method, or according to a non-recommended method, with a knit cover placed between the facepiece cushion and face, with a towel placed between the facepiece cushion and face, or with the headband on a helmet. The leakage rate of each wearing variation was then measured, according to the procedure for determining the protection factor of respiratory protective equipment, using atmospheric dust as required by JIS T8150. The average leakage rate for the RPR was 1.82–10.92%, whereas that of the PAPR was 0.18–0.42%. The performance of the RPR decreased when worn in methods outside of recommendations; however, there was no significant decrease in the performance of PAPR under any method of wear. Therefore, a PAPR is recommended for work in which a replaceable or disposable particulate respirator fails to provide sufficient protection against hazardous dust substances, or for workers who are unable to use a particulate respirator according to the recommended method owing to the work environment or health conditions.
Maintenance-of-way workers in North America who construct railroad tracks utilize specialized powered-hand tools, which lead to hand-transmitted vibration exposure. In this study, the maintenance-of-way workers were surveyed about neuro-musculoskeletal disorders, powered-hand tools and work practices. Information about vibration emission data of trade specific powered-hand tools for the North American and European Union markets was searched online to obtain respective user information of manufacturer and compared to non-commercial international data banks. The survey showed that maintenance-of-way workers frequently reported typical hand-transmitted vibration-related symptoms, and appear to be at a risk for neuro-musculoskeletal disorders of the upper extremity. Of all of the powered-hand tools used by this trade, 88% of the selected tools exceeded a=5 m/s2 and were above vibration magnitudes of common tools of other comparable industries. This may create a risk if these tools are used throughout an 8-h work day and management of vibration exposure may be needed. In the North-American market, limited or no vibration emission data is available from manufacturers or distributors. Vibration emission information for powered-hand tools, including vibration emission levels (in m/s2), uncertainty factor K, and the applied testing standard/norm may assist employers, users and occupational health providers to better assess, compare and manage risk.
The understaffing of nursery schools and kindergartens and the increasing workload of childcare workers are becoming significant issues in Japan. In this study, a cross-sectional survey was conducted to investigate the stress experienced by childcare workers and its antecedents. We distributed 2,640 questionnaires to childcare workers in Miyagi prefecture, obtaining a response rate of 51.9% (n=1,370). Finally, 1,210 valid questionnaires were used in the analysis. As a stress indicator, psychological distress was measured with the Kessler Screening Scale for Psychological Distress (K6). The mean K6 score was 7.0 (SD=5.4), and the prevalence of psychological distress (K6 score ≥5) was 60.0%. Considering work-related factors, the mean scores were as follows: supervisor support 11.8 (2.6), coworker support 12.1 (2.0), work engagement 3.2 (1.2), and effort-reward ratio 0.93 (0.53). A multivariate logistic regression analysis with adjustment for possible confounders revealed that increased psychological distress was associated with higher effort-reward ratio, lower support from supervisors and coworkers, lower work engagement, and insufficient sleep. These results suggest that elevated psychological distress is strongly associated with effort-reward imbalance, while high work engagement in childcare workers helped to reduce their distress.
The rapid growth of nanotechnology has increased the occupational exposure to nanomaterials. On the other hand, a growing body of evidence considers exposure to these materials to be hazardous. Therefore, it is necessary to examine the effects of occupational exposure to these materials by different methods. Biological monitoring, especially the investigation of oxidative stress induced by exposure to nanomaterials, can provide useful information for researchers. This study systematically reviews studies that have investigated oxidative stress caused by occupational exposure to nanomaterials. The search was conducted on the PubMed, Scopus and Web of Science databases. Of the 266 studies we obtained in our initial search, eventually 11 were included in our study. There is currently no specific biomarker for investigating oxidative stress induced by exposure to nanomaterials. Therefore, the reviewed studies have used different biomarkers in different biological fluids for this purpose. Also, the methods of assessing occupational exposure to nanomaterials in the investigated studies were very diverse. Given the approach of the investigated studies to biomarkers and exposure assessment methods, finding a specific biomarker for investigating exposure to nanomaterials seems unattainable. But reaching a group of biomarkers, to assess exposure to nanomaterials seems more applicable and achievable.
Post-traumatic stress disorder (PTSD) may arise after events involving a risk to physical integrity or to life, one’s own or that of others. It is characterized by intrusive symptoms, avoidance behaviors, and hyper-excitability. Outside certain categories (e.g., military and police), the syndrome is rarely described in the occupational setting. We report here five unusual cases of work-related PTSD, diagnosed with an interdisciplinary protocol (occupational health visit, psychiatric interview, psychological counselling and testing): (1) a 51 yr-old woman who had undergone three armed robbery attempts while working in a peripheral post office; (2) a 53 yr-old maintenance workman who had suffered serious burns on the job; (3) a 33 yr-old beauty center receptionist after sexual harassment and stalking by her male employer; (4) a 57 yr-old male psychiatrist assaulted by a psychotic outpatient; (5) a 40 yr-old woman, sales manager in a shoe store, after physical aggression by a thief. All patients required psychiatric help and pharmacological treatment, with difficulty of varying degrees in resuming work. We conclude that PTSD can develop even in professional categories generally considered to be at low risk. In such cases, a correct interdisciplinary diagnostic approach is fundamental for addressing therapy and for medico-legal actions.
While a number of work-related events have been proposed as risk factors for depression, a majority of studies have focused only on a few events in a single study. Therefore, we conducted a web-based longitudinal study to comprehensively investigate the impact of various work-related events on depressive symptoms. Ten thousand Japanese workers representing the Japanese working population were recruited online and questioned on their experiences of 36 work-related events in the past year. Their depressive symptoms were also assessed based on the Center for Epidemiologic Studies Depression Scale. Two years later, 3,098 participants responded to a follow-up study. By excluding 1,030 participants who were classified as being depressed in the baseline survey, data of 2,068 participants were analyzed. Odds ratios (OR) were calculated using multivariate logistic regression to assess the effect of work-related events on depressive symptoms. Eighteen events were found to be risk factors and were sorted into four types as follows: experience of an accident or disaster (OR: 4.78–7.67), excessive responsibility (OR: 3.01–3.62), drastic change in workstyle or workload (OR: 2.38–3.08), and interpersonal conflict (OR: 2.41–11.16). The current results, including magnitude relationship of ORs, should be utilized for promoting psychosocially healthy work environment.
This study determined the association of cold-related symptoms with workplace temperature and thermal insulation of clothing among Thai chicken industry workers. Three hundred workers were interviewed regarding cold-related symptoms, which were regressed on worksite temperature and protective clothing. In total, 80% of workers reported respiratory symptoms; 23%, cardiac symptoms; 62%, circulation disturbances; 42%, thirst; 56%, drying of the mouth; and 82%, degradation of their performance. When adjusted for personal characteristics, respiratory symptoms were 1.1–2.2 times more prevalent at –22–10°C than at 10–23°C. At –22–10°C, cardiac symptoms increased by 45%, chest pain by 91%, peripheral circulation disturbances by 25%, and drying of the mouth by 57%. Wearing protective clothing with at least 1.1 clo units was associated with marked reductions in symptom prevalence. Therefore, temperatures lower than 10°C increased prevalence of cold-related symptoms, which are largely preventable by appropriate clothing use.
We aimed to investigate the association between working hours and poor glycemic control using a cross-sectional data from the Korea National Health and Nutrition Examination Survey (KNHANES). The participants who were medically diagnosed with diabetes mellitus by a physician were defined as diabetic patients, and patients with hemoglobin A1c (HbA1c) levels>9.0% were considered as “poorly controlled.” The association of HbA1c level with working hours was examined by linear regression plot, using local regression line and logistic regression analyses. The local regression plot showed a smooth increasing pattern: the longer were the working hours, the higher were the HbA1c levels, even though it was not statistically significant. Odds ratios of working hours over 52 h per week were higher with the criterion of poor diabetic control (HbA1c>9.0%). The results were significant in elderly female workers (odds ratio 3.30, 95% confidence interval 1.19–9.18). Long working hours were associated with poor glycemic control, specifically among elderly female workers with diabetes.
High level of work-family conflict (WFC) is an important risk factor for stress-related health outcomes. However, many studies are cross-sectional studies. In this study, we aimed to clarify how changes in WFC levels over a period 5 years can affect workers' mental and physical health, and to clarify whether there are gender differences of them. This study examined 1,808 civil servants (1,258 men and 550 women) aged 20–65 years working in a local government in the west coast of Japan from 2003 to 2008. Logistic regression analyses were used to examine whether the change in WFC contributes to workers’ health problems and whether there are gender differences. This study revealed association sustained high WFC and deterioration of WFC conflict with poor mental health and poor job satisfaction for both men and women. In men high WFC conflict and deterioration was associated with poor mental health (OR=2.74). On the other hand, women had strong relationship between WFC changes and poor physical health (OR=2.64). WFC was an important factor as a social determinant of health of Japanese civil servants, and the change in WFC affects subsequent health problems with different trends in men and women.
The aim of the present study was to demonstrate the effect of verbal ratings on arousal in the electroencephalogram (EEG) and psychomotor vigilance test (PVT) performance. Thirty participants underwent the PVT for 40 min in three experimental conditions: (1) Rating condition, in which they verbally rated subjective sleepiness with Karolinska sleepiness scale, following pure tone sound played every 20 s during PVT, (2) No-rating condition, in which they underwent PVT with the similar sound as the Rating experiment but without the verbal rating task, and (3) Control condition, in which they underwent PVT with a no-sound stimulus and without the verbal rating task. The results show that during the first half of the task epoch, alpha power density was lower in the Rating than in the No-rating condition, while performance was not different between the conditions. During the second half of the task epoch, performance was better in the Non-rating than in the Rating condition, but no difference in the alpha power density. These results suggest that performance deterioration could be masked by the arousal effect of the dual task itself. It could also explain why the PVT performance and arousal in EEG sometimes dissociate, particularly in dual task situations.
The Japanese Industrial Safety and Health Act was first enacted in 1972. The purpose of this Act is to secure the safety and health of workers in the workplace, as well as to facilitate the establishment of a comfortable work environment. To fulfill these purposes, the Industrial Safety and Health Act aims to clarify the responsibility system in the workplace and to promote proactive efforts by both employers and employees to maintain safety and health in the workplace. Specifically, it is expected that occupational accidents will be prevented by obligating employers to appoint safety and health personnel in accordance with the Act. In this paper, I introduce the features and key points of the Industrial Safety and Health Act, especially in relation to Chapter 3 (Articles 10–19), which provides for the organization of the safety and health management system. In addition, I describe recent amendments to the Act.
We investigated the effects of an intervention aiming at enhancing four types of team-level social capital (bonding, bridging and two types of linking social capital) in six dairy plants with a total of 60 teams. Social capital and work engagement was assessed in baseline and follow-up surveys. The follow-up period was approximately 20 months, comprising an intervention period of 12 months. Intervention effects were assessed by comparing changes in team-level mean-scores for teams that had developed action plans with teams that had not. Results show that teams that had developed action plans generally showed a larger increase in social capital and work engagement than other teams. Differences were statistically significant for linking social capital towards the workplace as a whole and work engagement. However, effect sizes indicate an effect of the action plans despite the lack of statistical significance. Moreover, the self-reported level of implementation of the action plans was associated with the size and direction of the observed change.
Individuals with autism spectrum disorders are at a high risk of experiencing depressive symptoms. However, the relationship between autistic traits and depressive symptoms is unclear. This study aimed to identify which autistic traits are related to depressive symptoms in Japanese workers. The study participants included 2,049 workers from all areas of Japan. Autistic traits and depressive symptoms were measured using an abridged Japanese version of the Autism-Spectrum Quotient (AQ-Short) and the Japanese version of the K6 scale, respectively. The AQ-Short comprises five autistic trait subcomponents that assess fascination for numbers/patterns, difficulties with imagination, preference for routine, difficulties with social skills, and attention-switching difficulties. Linear regression analyses were performed to estimate the association between total and subcomponent autistic trait scores and depressive symptoms. Participants with higher total autistic trait scores were significantly more likely to have depressive symptoms (p<0.001). When scores on the five autistic trait subcomponents were entered simultaneously into the model, participants with higher scores on all subcomponents other than ‘difficulties with imagination’ were significantly more likely to report depressive symptoms. Total autistic traits and autistic trait subcomponents could be used for early detection of the risk of depressive symptoms.
From 2011–2015, the National Institute for Occupational Safety and Health Nanotechnology Field Studies Team conducted 11 evaluations at worksites that either produced engineered nanomaterials (ENMs) via a wet process or used ENMs in a wetted, suspended, or slurry form. Wet handling or processing of ENMs reduces potential exposure compared to dry handling or processing; however, air sampling data indicated exposures may still occur. Information was gathered about each company, production processes, ENMs of interest, and control measures. Exposure assessments included air sampling using filter media, surface wipe sampling, and real-time particle counting by direct-reading instruments. Electron microscopy analysis of air filters confirmed the presence of ENMs of interest (10 of 11 sites). When a method was available, chemical analysis of filters was also used to detect the presence of ENMs (nine of 11 sites). Wipe samples were collected at four of the 11 sites, and, in each case, confirmed the presence of ENMs on surfaces. Direct-reading data showed potential nanomaterial emissions (nine of 11 sites). Engineering controls included fume hoods, cleanrooms, and enclosed processes. Personal protective equipment was required during all 11 evaluations. Recommendations to address potential exposures were provided to each company following the hierarchy of controls.
Competency is important for professionals’ effective performance and career development. However, little is known about the necessary competencies and proficiency in these for Thai safety officers. Therefore, this study aimed to identify the necessary competencies for this group and to compare proficiency in each competency between senior and junior safety officers. A descriptive, cross-sectional study was conducted among 73 safety officers using a self-administered questionnaire. Twenty-five competencies were classified as necessary. Mean proficiency scores were higher for senior safety officers than for more junior safety officers for all examined competencies; however, this difference was not statistically significant for ‘first aid’ or for ‘air sampling and analytical methods.’ Regulatory compliance was assessed as the most important competency. Gaps between necessity and proficiency were observed in managing safety programs for the junior group. In both groups, proficiency was lowest in the competency of mental health. The results indicate that Thai safety officers’ training needs may be particularly high for regulatory compliance, managing safety programs, and mental health. Lifelong learning is important for enabling occupational safety and health practitioners to fulfill current requirements in Thailand and elsewhere. Multiple training approaches and a specialist qualification program may encourage competency development, especially for junior practitioners.
This study evaluated whether cold-induced deterioration in neuromuscular function can be restored by intermittently increasing the workload. We examined the level of muscular strain, agonist-antagonist co-activation, the occurrence of EMG gaps and neuromuscular efficiency in wrist flexor and extensor muscles at 21°C (TN) and 4°C (C10) with a 10%MVC workload. During second exposure to 4°C (C50) the workload was increased every fourth minute to 50%MVC. The results indicated that muscular strain and co-activation was the highest and the amount of EMG gaps and neuromuscular efficiency the lowest at C10. By intermittently increasing the workload at C50 we were able to reduce muscular strain and co-activation (p<0.05) and induce a trend like increase in EMG gaps and enhance neuromuscular efficiency in relation to C10 (NS). It may be concluded that intermittently increasing the workload, i.e. breaking the monotonous work cycle was able to partially restore neuromuscular function.
Leukotrienes (LTs) are involved in the pathogenesis of lung fibrosis and were increased in exhaled breath condensate (EBC) of the patients with pneumoconiosis. However the possible influence of extra-pulmonary disorders on the EBC markers is not known. Therefore in parallel with EBC, LTs’ levels in the plasma and urine were measured in patients with pneumoconiosis (45x asbestos exposure, 37x silica exposure) and in 27 controls. Individual LTs B4, C4, D4 and E4 were measured by liquid chromatography - electrospray ionization - tandem mass spectrometry (LC-ESI-MS/MS). In EBC, LT D4 and LT E4 were increased in both groups of patients (p<0.001 and p<0.05), comparing with the controls. Both LT B4 and cysteinyl LTs were elevated in asbestos-exposed subjects (p<0.05). Asbestosis with more severe radiological signs (s1/s2-t3/u2) and lung functions impairment has shown higher cysteinyl LTs and LT C4 in the EBC (p<0.05) than mild asbestosis (s1/s0-s1/s1). In addition, in the subjects with asbestosis, cysteinyl LTs in EBC correlated with TLC (-0.313, p<0.05) and TLCO/Hb (-0.307, p<0.05), and LT C4 with TLC (-0.358, p<0.05). In pneumoconioses, EBC appears the most useful from the 3 fluids studied.
Many work activities include hazards to workers, and among these biological risk is particularly important, mostly because of different types of exposure, contact with highly dangerous agents, lack of limit values able to compare all exposures, presence of workers with defective immune systems and therefore more susceptible to the risk. Bioaerosols and dust are considered important vehicles of microganisms at workplaces and interaction with other occupational agents is assumed. Moreover, biological risk can be significant in countries with increasing economic development or particular habits and some biological agents are also classified as carcinogenic to human. Specific emerging biological risks have been recently pointed out by Risk Observatory of the European Agency for Safety and Health at work, and we must consider the worker’s attitude and behaviour, influenced by his own perception of risk more than his real knowledge, that could over-underestimate the risk itself. Therefore, biological risk at work requires a complex approach in relation to risk assessment and risk management, made more difficult due to the wide variety of biological agents, working environments and working techniques that can determine the exposures.
The mental health problems of employees have become a major occupational health issue in Japan. External employee assistance program providers (EAP) have become important in mental health care for workers, but their activities are poorly documented. This descriptive study was undertaken to clarify the status and future tasks of EAP in Japan. The subjects were all EAP (n=27) registered in the Japanese Chapter of Employee Assistance Professionals Association. The questionnaire survey was conducted in January 2007. We received 13 replies, a response rate of 54.2%. Most EAP provided seminars, stress checks, stress management, counseling, and support for a return to work. The number of EAP contracted with small-scale enterprises was small. EAP communicated infrequently with companies. To promote the use of EAP, their advertising, education and training of staff, accumulation of scientific evidence, development of an official certification system for staff, and improvement of contents of EAP services were cited.
The present study analyzes the effect of work stressors, personal strain and coping resources on burnout among Chinese medical professionals. A total of 2,721 medical professionals were selected using the stratified cluster sampling method. A Chinese version of the Maslach Burnout Inventory-General Survey was used to measure burnout, whereas the Occupation Stress Inventory-Revised Edition was used to evaluate work stressors, personal strain, and coping resources. The structural equation model (SEM) was established to test the effect of work stressors, personal strain, and coping resources on burnout. Among the predictive factors for burnout, work stressors and personal strain were the primary risk factors, whereas coping resources make up the important protective factor. The result from SEM indicated that work stressors had both direct and indirect effects on burnout, with the indirect effect mediated by both personal strain and coping resources. Coping resources only affected burnout indirectly, as mediated by personal strain, whereas personal strain affected burnout independently. The results suggest that work stressors, personal strain, and coping resources play important roles in burnout among medical professionals. To prevent burnout, such countermeasures as controlling the work stressors, reducing personal strain, and strengthening coping resources are recommended.
This study examines predictors of sickness absence in patients presenting to a health practitioner with acute/subacute low back pain (LBP). Aims of this study were to identify baseline-variables that detect patients with a new LBP episode at risk of sickness absence and to identify prognostic models for sickness absence at different time points after initial presentation. Prospective cohort study investigating 310 patients presenting to a health practitioner with a new episode of LBP at baseline, three-, six-, twelve-week and six-month follow-up, addressing work-related, psychological and biomedical factors. Multivariate logistic regression analysis was performed to identify baseline-predictors of sickness absence at different time points. Prognostic models comprised ‘job control’, ‘depression’ and ‘functional limitation’ as predictive baseline-factors of sickness absence at three and six-week follow-up with ‘job control’ being the best single predictor (OR 0.47; 95%CI 0.26–0.87). The six-week model explained 47% of variance of sickness absence at six-week follow-up (p<0.001). The prediction of sickness absence beyond six-weeks is limited, and health practitioners should re-assess patients at six weeks, especially if they have previously been identified as at risk of sickness absence. This would allow timely intervention with measures designed to reduce the likelihood of prolonged sickness absence.
The WBGT heat stress index has been well tested under a variety of climatic conditions and quantitative links have been established between WBGT and the work-rest cycles needed to prevent heat stress effects at the workplace. While there are more specific methods based on individual physiological measurements to determine heat strain in an individual worker, the WBGT index is used in international and national standards to specify workplace heat stress risks. In order to assess time trends of occupational heat exposure at population level weather station records or climate modelling are the most widely available data sources. The prescribed method to measure WBGT requires special equipment which is not used at weather stations. We compared published methods to calculate outdoor and indoor WBGT from standard climate data, such as air temperature, dew point temperature, wind speed and solar radiation. Specific criteria for recommending a method were developed and original measurements were used to evaluate the different methods. We recommend the method of Liljegren et al. (2008) for calculating outdoor WBGT and the method by Bernard et al. (1999) for indoor WBGT when estimating climate change impacts on occupational heat stress at a population level.
This study investigated the distinctiveness between workaholism and work engagement by examining their longitudinal relationships (measurement interval=7 months) with well-being and performance in a sample of 1,967 Japanese employees from various occupations. Based on a previous cross-sectional study (Shimazu & Schaufeli, 2009), we expected that workaholism predicts future unwell-being (i.e., high ill-health and low life satisfaction) and poor job performance, whereas work engagement predicts future well-being (i.e., low ill-health and high life satisfaction) and superior job performance. T1–T2 changes in ill-health, life satisfaction and job performance were measured as residual scores that were then included in the structural equation model. Results showed that workaholism and work engagement were weakly and positively related to each other. In addition, workaholism was related to an increase in ill-health and to a decrease in life satisfaction. In contrast, work engagement was related to a decrease in ill-health and to increases in both life satisfaction and job performance. These findings suggest that workaholism and work engagement are two different kinds of concepts that are oppositely related to well-being and performance.
29 physicians (A1-Group) and 24 physicians (A2-Group) attending the 1st and 2nd “Asian Intensive Reader of Pneumoconiosis” (AIR Pneumo) training course, respectively, and 22 physicians (B-Group) attending the Brazilian training course took the examination of reading the 60-film set. The objective of the study was firstly to investigate the factor structure of physiciansf proficiency of reading pneumoconiosis chest X-ray, and secondly to examine differences in factor scores between groups. Reading results in terms of the 8-index of all examinees (Examinee Group) were subjected to the exploratory factor analysis. A 4-factor was analyzed to structure the 8-index: the specificity for pneumoconiosis, specificity for large opacities, specificity for pleural plaque and shape differentiation for small opacities loaded on the Factor 1; the sensitivity for pneumoconiosis and sensitivity for large opacities loaded on the Factor 2; the sensitivity for pleural plaque loaded on the Factor 3; the profusion increment consistency loaded on the Factor 4. 4-Factor scores were compared between each other of the three groups. The Factor 2 scores in A1 and A2 groups were significantly higher than in B-Group. Four factors could reflect four aspects of reading proficiency of pneumoconiosis X-ray, and it was suggested that 4-factor scores could also assess the attained skills appropriately.