J Occup Rehabil DOI 10.1007/s10926-013-9493-2
Chinese Translation and Cross Cultural Adaptation of the Workstyle Short Form Andy S. K. Cheng · Grace P. Y. Szeto · Yan Wen Xu · Michael Feuerstein
© Springer Science+Business Media New York 2013
Abstract Introduction Workstyle as it is related to symptoms of musculoskeletal symptoms of the upper limbs is the behavioural, cognitive and physical responses that occur in individuals to increases in work demands. A self report measure of this construct was developed that was both associated with and predictive of work related upper extremity symptoms. The aim of this study was to translate, culturally adapt, and validate a Chinese version of the Workstyle Short Form (C-WSF). Methods The C-WSF was translated following a forward and backward translation approach. Content validity was examined by item- and scale-level content validity indices. The intra-class correlation coefficient (ICC) was used to analyze test–retest reliability. Exploratory factor analysis was used to identify factor structures and the internal consistency of these factors was assessed by calculating Cronbach’s alpha reliability coefficients. The construct validity of the C-WSF was first determined by convergence in relation to the Cumulative Symptoms Score for Upper Extremity symptoms and then by comparison of those with and without upper extremity pain in Chinese cooks, a work with a high level of exposures to varying levels of work demands The opinions and assertions contained herein are the private views of the authors and are not to be construed as being official or as reflecting the views of the Uniformed Services University of the Health Sciences or the Department of Defense. A. S. K. Cheng (&) · G. P. Y. Szeto · Y. W. Xu Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong e-mail:
[email protected] M. Feuerstein Departments of Medical and Clinical Psychology and Preventive Medicine and Biometrics, Uniformed Services University of the Health Sciences, Bethesda, MD, USA
coupled with exposure to workplace psychosocial and biomechanical stressors. Results The C-WSF demonstrated excellent item- and scale-level content validity index ([0.9). The factor structure of C-WSF was similar to its original English version. The internal consistency of different subscales of C-WSF ranged from 0.65 to 0.91. The ICC was between 0.79 and 0.93 indicating good test–retest reliability. C-WSF was significantly correlated with upper extremity symptoms (r = 0.34, p \ 0.001). Conclusions CWSF is a reliable and valid version of the Workstyle measures for use in Chinese population. Keywords Workstyle · Self report measure · Chinese translation · Validation · Work-related musculoskeletal upper extremity pain · Chinese cooks
Introduction Work-related musculoskeletal symptoms and disorders are a major concern for public health [1, 2]. They also represent a major source of work disability [3, 4] which incur both a personal and economic impact for all stakeholders, particularly the employer and the worker with WMSDs. Workrelated upper extremity disorders and symptoms (WRUES/ Ds) have become a major concern in many countries and have been steadily progressing for several decades [5]. WRUES/Ds are influenced by a number of risk factors including sociodemographics, work organizational factors, physical work demands, and individual psychosocial variables [6–8]. In recent years, because of the widespread of WMSDs in various work contexts, there is a strong demand to develop simple tools for risk assessment and management [9]. The workstyle model proposed by Feuerstein and colleagues [10, 11] focuses on the interaction of physical risk
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factors and psychosocial factors in the work environment as a mechanism in the development, exacerbation and maintenance of WRUES/Ds. It was developed based on evidence of associations between characteristic responses observed in various individuals to increased work demands and upper extremity symptoms [12–14]. This increased work demand can in certain workers lead to heightened levels of physiological and psychological arousal, which may interact with specific physical and psychosocial risk factors in the workplace. For example, a worker may adopt more awkward work postures, fail to rest or take breaks, exhibit high personal work expectations, ignore and/or tolerate existing symptoms as ways to cope with the stress from work. Repeated elicitation of this adverse workstyle may result in the development, exacerbation and/or maintenance of WRUES/Ds [10, 11]. Feuerstein et al. [15] developed a self-report Workstyle measure which consisted of 91 items to measure components of workstyle. There were ten factors in the measure, with the following subscales: Working Through Pain, Social Reactivity, Limited Workplace Support, Deadlines/Pressure, Self-imposed Workpace/Workload, Breaks, Mood, Pain/ Tension, Autonomic Response and Numbness/Tingling. This full-scale Workstyle measure demonstrated high internal consistency among the subscales (Cronbach’s α = 0.61–0.91) and good test–retest reliability of the total score (r = 0.90, p\0.01) when assessing office workers [15]. In response to the request for a shorter version of the Workstyle measure, factor analyses of the full-scale Workstyle measure were conducted to reduce the number of total items. Each of the subscales was then further reduced by randomly selecting half of the items within each subscale. Additionally, two subscales from the original measure (Pain/ Tension and Numbness/Tingling) were eliminated because they were redundant to the outcomes the workstyle measure was intended to be related to or predict. These items were not used to calculate the original workstyle total score. As a result, the WSF evolved which consists of 32 items only. The WSF demonstrated high degree of internal consistency (Cronbach’s α = 0.89) and good test–retest reliability of the total score (r = 0.88, p \ 0.01). In addition, the short form score demonstrated significant correlations with measures of pain, r = 0.41, p\0.01; upper extremity symptoms, r = 0.33, p \ 0.01; functional limitation, r = 0.43, p \ 0.01; and an inverse relationship to overall physical health, r = −0.23, p\0.01 [16]. The catering industry is a costly service in terms of WMSDs. In Norway from 1992 to 2003, caterers had the second highest rate of WMSDs in that country [17]. Chinese restaurants represent a service industry where a number of WMSDs risk factors can be present and represent a large part of the catering industry worldwide. With globalization, Chinese restaurants can be found in almost
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every city in the world [18, 19]. According to Chinese Restaurant News, there are nearly 43,000 Chinese restaurants in the United States alone—three times the total number of the three greatest American fast-food restaurants —turning over US$20 billion a year [20]. According to the 2008 UK Chinese Immigration Concern Committee (CICC) survey, there are around 17,000 Chinese catering outlets in the UK, with a turnover of £4.9 billion a year and 100,000 workers [21]. As an international city, Hong Kong has nearly 30,000 restaurants, with more than 60 % of them Chinese restaurants employing more than 200,000 workers [22]. Chinese restaurants are clearly a significant portion of the restaurant industry across the globe. The working environment and processes in Chinese restaurants are different from those of their Western counterparts. Cooks usually have to hold cooking utensils for extended periods of time, toss woks and barbecue, all of which demands forceful exertion of the hands, wrists and forearms. Servers often have to deliver large and heavy dishes, which may require excessive stretching and gripping with substantial force. This intense exertion can induce muscle strain and increase the likelihood of WMSDs of the upper extremity. The time demands often present during peak times can also create higher levels of psychosocial and workplace and individual levels psychological stress further exposing the musculoskeletal system to increased and or prolonged exposure to the biomechanical exposures. A qualitative study conducted by Tsai [23] used ethnographic content analysis and interviews with Chinese immigrant restaurant employees and found that WMSDs (including aches and pains, soreness and numbness) were their most troubling occupational illnesses. Cooks were at higher risk of having WMSDs [24]. A retrospective case control study was conducted on a cohort of 52,261 Chinese restaurant cooks to investigate the prevalence of confirmed, diagnosed WMSDs, and found that the annual incidence of WMSDs was around 25 % for cooks, with suspect cases excluded [25]. Given the musculoskeletal problems that have been noted in the Chinese restaurant environment, the potential risk of this type of work for upper extremity symptom and the high incidence of Chinese as the primary language used in this industry and several others where upper extremity problems are prevalent. Use of the English version may lead to misinterpretation of the items, particularly where workers are concerned, as most lack the English-language proficiency to read and understand the questions. The purpose of this study was therefore to translate, culturally adapt, and validate a Chinese version of the WSF (the CWSF) so as to provide Chinese users a practical assessment and management tool. We hypothesized that the factor structure of C-WSF would be the same as its English
J Occup Rehabil
version. C-WSF was able to identify those Chinese cooks who have WRUES/Ds and those who are at WRUES/Ds risk exposure.
Methods Development of the C-WSF The develop process followed the five different stages proposed by Guillemin et al. [26] and Beaton et al. [27]. Stage 1: Forward Translation to Chinese The original version (Appendix 1) was translated into the Chinese language by two bilingual translators whose native language was Chinese. Both of them have no medical background and were unaware of the study proposal. Stage II: Synthesis of the Translations A multidisciplinary expert committee consisting of seven members: two translators, one occupational therapist, one physical therapist, one medical doctor, and two workers with medical history of work-related musculoskeletal upper extremity (UE) pain and disorders because of lateral epicondylitis, was setup. The therapists and medical doctor in this committee had more than 10 years’ experience in managing patients with work-related musculoskeletal UE pain and disorders. The members compared and discussed the translations with each other and with the original English version. After a few discrepancies were resolved by consensus, the two forward translations were formulated into a single version. Stage III: Translation Back to English The backward translation was performed by two bilingual translators whose native language was English. Both lacked medical backgrounds and were not aware of the prior translation procedures. They independently and blindly translated the synthetic version into English. Each English translation was then compared with the original English version and checked for inconsistencies. Likewise, the two backward translations were combined into a single English version. In addition, this English version was sent to the original author of WSF for comments. Finally, the expert committee consolidated the original questionnaire, the forward translations, the backward translations, and the corresponding comments from the original author to reach a consensus on any discrepancies to produce a pre-final version of C-WSF.
Content Validity Testing of the Pre-final Version Two expert panels were subsequently formed to conduct panel reviews on the content validity of the pre-final version of C-WSF. All panel members were independent of the multidisciplinary expert committee. The purpose of the first panel review was to evaluate the relevance and representativeness of the items in assessing work-related musculoskeletal UE pain and disorders among Chinese populations. The panel consisted of a medical consultant, two occupational therapists, one physical therapist, an ergonomist, and two occupational safety and health practitioners whose have had more than 10 years of working experience in patients with work-related musculoskeletal UE pain and disorders. The mean age of the panel members was 32.4 years (S.D. = 4.5). All members did not know the original English version of WSF. However, at the beginning of the panel review, they were explained the purpose of the study. The operational definition for workstyle and how workstyle predisposes an individual worker to increased risk of developing work-related musculoskeletal UE pain was introduced [10]. Two questionnaires were developed to guide the review of relevance, and representativeness of the translated questions respectively. Each panel member was instructed to complete each survey by rating the items using a 4-point Likert-type scale; for example, when evaluating relevance, a rating of one denoted “not relevant,” and four “highly relevant.” They were also encouraged to provide written comments to justify their evaluations if rating a single item below three. On the other hand, the purpose of the second panel review was to evaluate the understandability of the translated questions. There were seven panel members who were representatives from three trade unions including clerical, catering, and logistics industry. They had been working at that industry for more than 20 years. The mean age of the panel members was 47.8 years (S.D. = 7.3). A questionnaire was developed to guide the review of understandability of the translated questions. Each panel member was asked to comment generally about any difficulties they experienced in completing the questionnaire or in understanding the purpose and meaning of any question. Each panel member was instructed to rate the questions using a 4-point Likert-type scale ranging from “very difficult to understand” (which scored one) to “very easy to understand” (which score four). They were also encouraged to provide written comments to justify their evaluations if rating a single item below three. Content validity was assessed using the content validity index (CVI) [28]. The item-level content validity index (ICVI) was computed as the number of panel members giving a rating of either three or four to a question divided by the total number of panel members; that is, the
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J Occup Rehabil Table 1 Demographic characteristics of the participants (n = 305) Work-related musculoskeletal UE pain (n = 216)
No work-related musculoskeletal UE pain (n = 89)
40.81 (9.77)
38.73 (10.63)
Females
11.57 %
10.11 %
Males
88.43 %
89.89 %
18.06 %
14.61 %
Mean age (S.D.) Gender
Education Primary Secondary
78.70 %
83.15 %
Diploma
3.24 %
2.24 %
Mean years at current job (S.D.)
11.45 (5.34)
9.74 (6.07)
Mean working hours per day (S.D.)
10.55 (2.40)
10.34 (1.70)
Mean working days per week (S.D.)
6.06 (0.83)
5.83 (0.61)
Mean number of co-workers (S.D.)
2.52 (0.34)
1.73 (1.36)
53.57 %
47.09 %
46.43 %
52.91 %
Exercise habit Yes No
Psychometric Testing of C-WSF Participants
No significant differences between the groups on any variable
proportion in agreement on the relevance, representativeness, and understandability. The scale-level content validity index (S-CVI) was computed by calculating the average I-CVI across items. For a scale to be judged as having excellent content validity, it must comprise items with I-CVIs of 0.78 or higher and an S-CVI of 0.90 or higher [28]. The expert panels yielded an I-CVI of 0.86–1 for relevance, representativeness, and understandability, indicating excellent content validity. In addition, the S-CVI assigned to the whole scale by both expert panels were higher than 0.90, indicating the overall scale had been successfully culturally adapted and possessed excellent content validity in terms of relevance, representativeness, and understandability. Test–Retest Reliability Testing of the Pre-final Version A total of 90 workers were recruited by convenience sampling through the trade unions to evaluate the test– retest reliability of the pre-final version of the C-WSF. The inclusion criteria were: (1) at least 1 year’s experience in the current workplace; and (2) sufficiently literate to read and understand simple questions. All workers completed the C-WSF anonymously and voluntarily. After filling in the C-WSF, each was given a return envelope containing the second (identical) form and asked to complete and
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return 14 days after the first. Each C-WSF was given a code in order to track who had responded. The research team also checked the completion date of the second C-WSF in order to ensure at least 14 days had elapsed between surveys. The intra-class correlation coefficient (ICC) was used to estimate the test–retest reliability of individual questions on the C-WSF. Among 90 workers who had completed the first C-WSF, 78 sent back the second C-WSF. This resulted in a response rate of 88.9 %. The test–retest reliability indices of the CWSF questions estimated by ICC were between 0.79 and 0.93 (Table 1). If the criterion of ≥0.75 was adopted to indicate good reliability [29], all of the C-WSF questions demonstrated good test–retest reliability. In view of the acceptable content validity and test–retest reliability, the expert committee adopted this pre-final version as the final version, and performed further psychometric testing.
Volunteers from three catering trade unions were recruited during their participation in regular festive function organized by the trade union. The inclusion criteria were (1) aged 21–60 years; (2) not currently pregnant and had not been pregnant in the last year since pregnancy has been associated with upper extremity symptoms [30]; (3) employed fulltime (≥35 h/week); and (4) worked in current job as Chinese cook for at least the past year. Participants were seen as a whole to explain the purpose of the survey and asked to fill in a questionnaire which consisting of demographic information such as gender, age, education level, work history, number of co-workers, exercise habit, upper extremity symptom history, and C-WSF. If the participants reported musculoskeletal pain in any UE anatomical location (shoulder, elbow, and hand/wrist) in the past 12 months, they were seen individually and were asked the following five questions: 1. 2. 3. 4. 5.
“Do you think this problem was work-related?”; “Had you had any previous injury or trauma to the symptomatic area?”; “How long does this problem usually last?”; “How often have you had this problem in the past year?”; and “On average, describe the intensity of the problem?”.
The last three questions were used to determine the duration, frequency, and intensity of this symptom. From these data, a cumulative symptoms score for an UE anatomical location was computed [31]. This score has been shown to be sensitive to changes in symptom status [32].
J Occup Rehabil
Data Analysis
Three Hundred and five participants completed and returned the C-WSF. They were mainly men (88.9 %), with a mean age of 39.46 years (S.D. = 9.76). Participants had been working at their current job for an average of 12.28 years (S. D. = 4.06), worked an average of 10.49 h/day (S.D. = 2.22) and averaged 5.48 day/week (S.D. = 0.52) at their job. The most common education level (80.3 %) was secondary school. 51.8 % of them had exercise habit after work. Among them, 216 experienced UE musculoskeletal pain in the past 12 months and claimed that the symptom was work-related. Participants with work-related musculoskeletal UE pain did not differ from other participants on any demographic characteristics (Table 1).
total variance. The factor structure of C-WSF was similar to its original English version. The five items loaded on to first factor, which accounted for 15.75 % of the total variance measured “Social Reactivity”. The internal consistency of the first factor measured by Cronbach’s α was 0.91. The questions in the second factor included those eight questions measured two subscales in English version: “Mood” and “Autonomic Response”. It accounted for 12.82 % of the total variance and Cronbach’s α was 0.79. They were loaded on to a single factor in C-WSF may be due to their dichotomous format and/or similar construct which is related to emotions, and symptoms experienced during the periods of high work demands. As a result, these questions were grouped together according to the factor analysis in Chinese version and named collectively as “Response to Increased Work Demands”. The third factor consisted of all six questions measured “Working Through Pain” and accounted for 10.55 % of the total variance and Cronbach’s α was 0.84. The fourth factor included seven out of eight questions in English version on measuring “Limited Workplace Support” and “Deadlines/ Pressure”, instead of two separate factors. This factor accounts for 8.53 % of the total variance and Cronbach’s α was 0.79. In addition, the question which was not loaded on to this factor, as its English version does, was question 12 “I don’t really know where I stand despite all the effort I put into my work”. It was loaded on to the seventh factor as a single item, with factor loading 0.59, accounting for 4.51 % of the total variance. Nevertheless, when examining its factor loading on fourth factor, it was 0.40. In addition, when this item was analyzed together with other seven items to determine internal consistency, the Cronbach’s α value was 0.71. The Cronbach’s α was decreased by 0.08 and given that a coefficient greater than 0.70 is considered satisfactory reliability [34] this item was returned to the fourth factor and this factor was collectively called as “Workplace Stressors”. The total variance explained by this factor increased to 13.04 %. The fifth factor captured two items which were labeled as “Breaks” in the English version. This factor accounted for 5.56 % of the total variance and Cronbach’s α was 0.65. It was consistent with the English version, this factor had a negative loading, suggesting that these items were negatively associated with an “adverse workstyle” [15]. The last three items loaded on to sixth factor, which accounted for 4.78 % of the total variance measured “Self-imposed Workpace/Workload”. The Cronbach’s α of this factor was 0.69. Table 2 summarizes the factor structure of the C-WSF.
Factor Structure of C-WSF
Construct Validity
Exploratory factor analysis with varimax rotation indicated a seven-factor solution, which accounted for 62.49 % of the
As for the construct validity testing, convergence, and the known-groups approaches were used. The results that the
Descriptive statistics were used to describe the demographic characteristics of all participants. Exploratory factor analysis using the principal component extraction method followed by varimax rotation was used to explore the factor structure of the C-WSF. The cutoff Eigen value for each question was set at 1.0. The internal consistency of the factor structure or subscale of C-WSF was assessed by calculating Cronbach’s alpha reliability coefficients. The construct validity of the total score and subscale scores of C-WSF was first determined by convergence in relation to Cumulative Symptoms Score for UE symptoms by bivariate correlation analysis. Afterwards, known-groups method was conducted to examine the mean score difference of the total score and subscale scores of C-WSF between those with or without work-related musculoskeletal UE pain during past 12 months. If more than one UE anatomical location was reported to have pain, the most problematic location was chosen for this analysis in this study. Finally, receiver operating curves (ROC) analyses were carried out to evaluate the screening accuracy of this scale in discriminating between those with or without workrelated musculoskeletal UE pain. Calculating sensitivity and specificity for the C-WSF requires a cutoff score. Youden’s index [33] was used to choose an optimal cutoff score. All statistical analyses were performed using the IBM SPSS program version 20 for Windows; the significance level was set at p \ 0.05.
Results Participant Characteristics
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J Occup Rehabil Table 2 Factor structure of the C-WSF after principal component analysis using varimax rotation Questions
Factor loading
Working through Pain 1. 我會在疼痛、不舒適的情況下繼續工作,這樣才不會影響我的工作質量。
Variance
Cronbach’s α
10.55
0.84
15.75
0.91
13.04
0.71
0.43
(I keep working when I feel aching or discomfort, so that the quality of my work will not be affected.) 2. 在工作時,我的雙手和雙臂會感到疲勞。
0.75
(My hands and arms get tired at work.) 3. 在工作間工作時,我會感到疼痛。 (I feel aching while at work.) 4. 因為我對自己的手/臂/肩/頸痛毫無辦法,所以只能忍痛繼續工作。
0.80 0.85
(As I do not know how to relieve my aching hands/arms/shoulders/neck, I keep on working with pain.) 5. 我實在沒有辦法消除或緩解自己手/臂/肩/頸部所出現的各種症。
0.82
(I do not know how to eliminate or relieve various symptoms of my hands/arms/ shoulders/neck.) 6. 我的手指/手腕/雙手/雙臂(其中一處或多處)會做一些急促、猛烈、快速、突 然的動作。
0.49
(My fingers/wrists/hands/arms (one or more places) may make some abrupt, fierce, fast or sudden movements.) Social reactivity 7. 我不能中途停工,因為這樣做會讓其他工友對我有意見。
0.75
(I cannot interrupt my work because my other team members will be unhappy with me.) 8. 我不能中途停工,因為這樣做會讓老闆失望或增加他的負擔。
0.88
(I cannot interrupt my work, because it would disappoint my boss or increase his responsibility.) 9. 我不能中途停工,因為這樣做會讓同事失望或增加他們的負擔。
0.89
(I cannot interrupt my work, because it would disappoint my colleagues or increase their workload.) 10. 我不能中途停工,因為這樣做會影響我的評估、晉升,和/或讓我丟掉工作。
0.81
(I cannot interrupt my work, because it would affect my appraisal, promotion, and/or cause me to lose my job.) 11. 如果我關心自己的健康而放下工作,放鬆一下或做做運動,我的同事/老闆會對 我有意見。
0.68
(If I take a break from work for relaxation or physical exercises, my colleagues/boss will be unhappy with me.) Workplace Stressors 12. 儘管我在工作中付出了很大努力,但我還是真的不知道我的工作是否得到應有 的認可。
0.40
(Although I have worked very hard, I still do not know whether my work has been duly recognized.) 13. 如果你沒完成自己的工作,老闆不會讓你好過。
0.48
(If you have not finished your work, your boss will give you a hard time.) 14. 如果我向主管反映(一些)問題,比如某某同事沒有努力做好自己的本職工作, 這根本起不 了什麼作用,所以不如自己做多點。
0.47
(If I communicate some problems to the supervisor - for instance, that some coworkers have not been working hard enough - this has no effect, so I might as well just work harder.) 15. 上司或其他人對工作質量的要求與我不同,這一點讓我感到很沮喪。
0.69
(I feel very depressed, as my boss’ expectations on the quality of work are different from mine.) 16. 我的工作有太多的最後期限,所以總也干不完。 (I have too many deadlines and I can never finish my work.)
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0.59
J Occup Rehabil Table 2 continued Questions
Factor loading
17. 儘管我會有條理地安排自己的工作,以便能夠在最後期限前完成工作,但情況 在不斷變化,自己還是得更加努力地工作,以便按時完成。
Variance
Cronbach’s α
4.78
0.69
5.56
0.65
12.82
0.79
0.66
(Although I arrange my work in good order so that I can finish it before the deadline, things change so frequently that I have to work even harder to finish it on time.) 18. 我的工作時間表很難控制。
0.71
(My work schedule is hard to control.) 19. 我在自己的工作間工作時會感到壓力。 (I feel pressure at work.) Self-imposed Workpace/Workload 20. 工作中我會督促自己,確立高於上司和其他人的預期目標。
0.71
(I motivate myself to work harder and set up targets that are higher than those my boss and other colleagues have expected.) 21. 我的同事沒有做好自己的份內工作,我就得承擔更多的工作。
0.73
(If my colleagues fail to do their work, I have to assume more responsibilities.) 22. 別人會告訴我應該放慢節奏,工作不要那麼拼命。
0.45
(Others tell me to slow down and not to work so intensely.) Breaks 23. 在日常工作期間,我會中途停下來休息,做做伸展運動。
−0.80
(During my regular workday I take breaks to do some stretches.) 24. 在工作間工作時,我會不時停下來休息。
−0.81
(While at work I occasionally stop working to take a break.) Response to Increased Work Demands 25. 憤怒
0.58
(Anger) 26. 失控
0.70
(Loss of control) 27. 無法專注于/集中精力工作
0.63
(Difficulty focusing/concentrating on work) 28. 无精打采/筋疲力盡
0.64
(Listlessness or exhaustion) 29. 不能承受
0.62
(Inability to cope) 30. 脾氣暴躁/易怒
0.59
(Ill temper/irritability) 31. 雙腳冰涼
0.64
(Coldness in feet) 32. 雙手冰涼 (Coldness in hands) Backward translation in parentheses under the Chinese one
C-WSF subscales, summary scores, and total score were significantly correlated with UE symptoms. “Working Through Pain” (r = 0.29, p \ 0.001), “Workplace Stressors” (r = 0.23, p \ 0.001), and “Response to Increased Work Demand” (r = 0.25, p \ 0.001), were positively correlated with Cumulative Symptoms Score, whereas “Breaks” was negatively correlated (r = −0.12, p \ 0.05), with Cumulative Symptoms Score. Furthermore, the total
score of C-WSF demonstrated a significant positive association with Cumulative Symptoms Score (r = 0.34, p \ 0.001; Table 3). On the other hand, the known-groups method demonstrated that C-WSF was able to discriminate between individual who had have work-related musculoskeletal UE pain. Table 4 presents the results of the known-groups validity analysis. The mean score of “Working Through
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J Occup Rehabil Table 3 Correlation analysis of the total and subscale scores of C-WSF with cumulative symptom score for UE symptoms Variable
(1)
Working through pain (1)
–
Social reactivity (2) Workplace stressors (3)
(2)
(3)
(4)
(5)
(6)
(7)
(8)
(9)
(10)
0.52**
0.43**
0.07
0.02
0.05
0.77**
0.05
0.77**
0.29**
–
0.47**
0.21**
−0.07
−0.01
0.81**
−0.01
0.80**
0.10
–
0.0.27**
0.13*
0.00
0.79**
0.00
0.78**
0.23**
–
0.18**
−0.01
0.35**
−0.01
0.35**
0.04
–
−0.07
−0.07
0.07
-0.06
−0.12*
–
0.01
1.0**
0.17**
0.25**
–
0.01
0.99**
0.21**
Self-imposed workpace/workload (4) Breaks (5) Response to increased work demand (6) Workstyle characteristic responses (7) Workstyle reactivity (8)
–
0.20**
Total C-WSF score (9)
–
Total cumulative symptoms score (10)
0.34** –
* p \ 0.05 ** p \ 0.001
Table 4 Comparison of summary score of C-WSF between those with or without work-related musculoskeletal UE pain during past 12 months Work-related musculoskeletal UE pain (n = 215)
No work-related musculoskeletal UE pain (n = 89)
Score
Mean
Mean
Working through pain
10.07
1.94
9.96
2.15
13.35 4.99
2.33 0.89
Breaks
2.71
Response to increased work demand
0.82
Social Reactivity Workplace stressors Self-imposed workpace/workload
S.D.
t-statistic
p value
8.75
2.82
−4.69
\0.001**
8.08
2.09
−3.42
0.001**
12.61 4.93
3.03 1.07
−2.29 −0.55
0.023* 0.585
0.78
2.65
0.93
−0.41
0.516
1.04
0.50
0.70
−2.64
0.009**
S.D.
Summary score 1
34.00
5.73
31.72
6.20
−3.02
0.003**
Summary score 2
0.82
1.04
0.50
0.70
−2.64
0.009**
34.78
5.78
32.22
6.27
−3.42
0.001**
Total score
Summary score 1 = Workstyle characteristic responses to the workplace score: (sum of question 1–22) minus (sum of question 23–24) Summary score 2 = Workstyle reactivity to high work demands score: Sum of question 25–32 Total score = Summary score 1 Summary score 2 * p \ 0.05 ** p \ 0.001
Pain”, “Social Reactivity”, “Workplace Stressors”, “Response to increased work demand”, two summary scores, and total score of C-WSF were statistically higher for those who had had work-related musculoskeletal UE pain during past 12 months.
indicates acceptable discrimination and one of at least 0.80 indicates excellent discrimination. Overall, the area under the curve was 0.711 (p \ 0.001, 95 % CI 0.583–0.780) at a cutoff score of 37.75 with sensitivity of 0.602 and specificity of 0.866.
Screening Accuracy Discussion Figure 1 presents the ROC curve associated with the total CWSF scores. The area under the curve serves as an overall measure of discrimination between those with or without work-related musculoskeletal UE pain; perfect discrimination would yield an area of one, whereas a test that failed to discriminate would have an area of 0.5. According to Hosmer and Lemeshow [35], an area of at least 0.70
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This study demonstrates that the C-WSF shares similar psychometric properties as its English version although there were minor changes of the factor structures in C-WSF. Calculation of the total score of C-WSF is the same as the original version. It was supported that there is a significant correlation between workstyle total score and upper
J Occup Rehabil
Fig. 1 ROC curve of C-WSF total score and work-related musculoskeletal UE pain
extremity symptoms. However, the cutoff score of our study population is much higher than office worker which is 28 [14]. This difference indicates that cutoff score across different occupations and races may not be the same. For example, all participants in this study were Chinese cooks. Their working environment, equipment used, and the nature of work demands are significantly different from the office workers. There have been several studies reporting a higher prevalence of musculoskeletal problems in cooks than in other occupational workers. Ergonomic factors in the working condition such as working height, lifting load, and the number of dishes prepared were found to be risk factors for musculoskeletal disorders in cooks [36, 37]. Furthermore, cooks working at Chinese restaurants may need to use more physical energy when compare to their counterparts working at Western restaurants. A local case presentation of an on-site ergonomics assessment of the risk factors for work-related musculoskeletal disorders among three cooks working at a medium-sized Chinese restaurant in Hong Kong [38] showed that, on average, a Chinese cook spent around 2 min cooking a single dish. Upper limb functions such as finger pinching, hand grasping, elbow flexion and extension, and forearm pronation and supination were frequently employed during this activity, particularly when grasping a wok (weighing 2.8 kg on average) and tossing it in order to ensure the contents were evenly heated. Repetitive use of the upper limbs was also seen in the work of the barbecue and dim sum cooks, such as roasting meat and making dim sum. It has been reported that the repetitive use of arms and hands is an important risk factor for WMSDs [39–41]. This is
particularly true in Chinese banquet restaurants, where they may have to serve more than 1000 customers dinner at the same time for occasions such as wedding parties. In addition to physical demands, there are psychological demands specifically involved in the catering industry. Both types of demands rise substantially during peak dining hours. The cooks not only need to mentally keep track of different verbal or written orders from the diner, but also prepare the food according to recipe and different cooking procedures. Errors that can occur include forgetting to add seasoning or overcook the meat. These are the reason why the cooks often complained of too much work, too many different tasks, and much pressure on time [42]. Besides, people working in catering industry usually reported low control of work situations and poor support from coworkers [43] particularly in small restaurant, cook has to cooperate to make meals and wash the dishes in a restricted work area within the limited time of working hours. Although no studies could be found that describe the potential interaction between physical and mental demands while cooking food, other findings suggested that these demands could be interactive. For example, the study results from Devereux [44] suggested that physical and psychosocial risk factors may interact to increase the risk of self-reported low back disorders. In addition, increased time pressure is a consistent risk factor for symptoms in the lower back and/or upper extremity regions [45]. Further investigation on this interaction and how the cooks deal with heightened job stress is worthy of doing especially during peak dining hours. Some limitations of the current study should be noted. First, the sample used in this study is a convenience sample which could have biased the findings. Since no information was available on those who did not volunteer, it is not possible to assess how representative the sample was of the population of Chinese cooks. Future research needs to use a more representative sample of the Chinese workforce in general. Second, the discomfort data are cross-sectional; thus, they are subject to inherent limitations. The association between different components of WSF and the musculoskeletal pain should not be inferred to be causal. It is also possible that Chinese cooks with more severe musculoskeletal pain did not take part in the survey because they did not participate in the festive function organized the trade union. Third, the study relied on self-report, which is always subject to response styles, demand characteristics, and recall bias. With the increase in the number of multinational and multicultural research projects, the need to adapt health status measures for use in other than the source language has also grown rapidly. Most questionnaires have been developed in English-speaking countries [26] but even within these countries, researchers must consider immigrant populations in studies of health, especially when their exclusion could lead to a systematic bias in studies of
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health care utilization or quality of life [46]. As a result, cross-cultural adaptation of health-related self administered questionnaires is important to obtain psychometric equivalence between the original source and target versions of the questionnaire. The items should not only be translated well linguistically, but also must be adapted culturally to maintain the content validity of the instrument at a conceptual level across different cultures.
Appendix 1 Workstyle Short Form Please complete the following survey by checking the boxes that describe your experience at work. Part 1: Rate the degree to which each of the following items describes you at WORK by selecting the appropriate option
Almost never
Rarely
Sometimes
Frequently
Almost always
1. I continue to work with pain and discomfort so that the quality of my work won’t suffer.
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[]
[]
[]
[]
2. My hands and arms feel tired during the workday.
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[]
[]
[]
[]
3. I feel achy when I work at my workstation.
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[]
[]
[]
[]
4. Since there is really nothing that I can do about my pain in my hands/ arms/shoulders/neck, I just have to work through the pain.
[]
[]
[]
[]
[]
5. There really isn’t much I can do to help myself in terms of eliminating or reducing my symptoms in my hands/arms/shoulders/neck.
[]
[]
[]
[]
[]
6. My fingers/wrists/hands/arms (any one or combination) make jerky, quick, sudden movements
[]
[]
[]
[]
[]
7. I can’t take off from work because other people at work will think less of me.
[]
[]
[]
[]
[]
8. I can’t take off from work because I’d be letting down or burdening my boss.
[]
[]
[]
[]
[]
9. I can’t take off from work because I’d be letting down or burdening my coworkers.
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[]
[]
[]
[]
10. I can’t take off from work because it will negatively affect my evaluations, promotions, and/or job security.
[]
[]
[]
[]
[]
11. If I take time off to take care of my health or to exercise, my coworkers/boss with think less of me.
[]
[]
[]
[]
[]
12. I don’t really know where I stand despite all the effort I put into my work.
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[]
[]
[]
[]
13. The boss doesn’t let you forget it if you don’t get your work finished.
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[]
[]
[]
[]
14. If I bring up problem(s) to my supervisor, like a coworker not pulling his/her weight, it won’t make any difference anyway, so I just go ahead and do the work myself.
[]
[]
[]
[]
[]
15. It is frustrating to work for those who don’t have the same sense of quality that I do.
[]
[]
[]
[]
[]
16. I have too many deadlines and will never be able to get all my work done.
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[]
[]
[]
[]
17. Even if I organize my work so that I can meet deadlines, things change and then I have to work even harder to get my work done on time.
[]
[]
[]
[]
[]
18. My schedule at work is very uncontrollable.
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[]
[]
[]
[]
19. I feel pressured when I’m working at my workstation.
[]
[]
[]
[]
[]
20. I push myself and have higher expectations than my supervisor and others that I have to deal with at work.
[]
[]
[]
[]
[]
21. My coworkers don’t pull their weight and I have to take up the slack.
[]
[]
[]
[]
[]
22. Others tell me I should slow down and not work so hard.
[]
[]
[]
[]
[]
23. I take time to pause or stretch during a typical day at work.
[]
[]
[]
[]
[]
24. I take breaks when I am involved in a project at my workstation.
[]
[]
[]
[]
[]
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Part 2: Check all the behaviors/emotions/symptoms that you experience only during periods of high work demands/ work load.
25. Anger
[]
26. Out of control
[]
27. Have trouble concentrating/focusing on work 28. Depleted/worn out
[] []
29. Overwhelmed
[]
30. Short fuse/irritable
[]
31. Cold feet
[]
32. Cold hands
[]
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