Journal of Health and Safety at Work

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Introduction: In Laboratory accusations a wide range of hand-held tools are used due to nature of their work. Long-term and repeated use of these tools has led the laboratory workers to suffer from upper limb disorders. The present study was designed and implemented with the aim of investigating the usability of different models of pipettes used in the laboratories of the Tehran University of Medical Sciences, employing subjective assessment methods for selecting the best pipette models.

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Material and Method: This cross-sectional and analytical-descriptive study was performed among 35 laboratories employees of Tehran University of Medical Sciences. First, four models of the widely used pipettes were selected and their usability-related characteristics were investigated by a visual analog scale (VAS). Judgments concerned the usability of the pipettes done based on the criteria provided by the International Organization for Standardization 9241-11(1998) and 20282-2(2006). Data analysis was performed, using SPSS software version 22.

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Result: The overall evaluation of the users in relation to the characteristics of the pipettes indicated that the highest VAS score was belonged to pipette A, C, and D, respectively. Furthermore, pipette B was selected as the most undesirable one by users. Results related to the usability criteria of pipette showed that of the four models of study pipettes, pipette A has been ranked first in two criteria (satisfaction and effectiveness). Regarding the efficiency, the first rank was for C pipette and the second rank was for pipette A. Pipette B obtained the lowest scores for all given criteria.

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Conclusion: Shorter and lighter pipettes, which were designed according to ergonomic principles, had greater usability from the perspective of users and it could cause a better subjective assessment comparing to the other models.

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Introduction: Usability has been defined as the extent to which specific users can efficiently use a product to achieve specific goals. Along with the increased number of the elderly population, there is a need for user-centered products for this group of people. Smartphones are widely used products in modern society. USE (Usefulness, Satisfaction, and Ease of use) questionnaire is an easy-to-use, quick, and accurate instrument to assess product/service usability. Thus, this study was done to determine the validity and reliability of the Farsi version of the USE questionnaire to evaluate the usability of smartphones for elderly users.
Material and Methods: The USE questionnaire was developed by Lund (2001) to assess usability, considering four separate dimensions: usefulness, satisfaction, ease of use, and ease of learning. This is a 30-item questionnaire that evaluates usability on a 7-point Likert scale. In order to assess the face and content validity of the questionnaire, a panel of nine experts was asked to rate the relevancy, clarity, simplicity, and necessity of each question using the Likert scale. Subsequently, the Content Validity Ratio (CVR) and Content Validity Index (CVI) were computed. In order to confirm the reliability of the questionnaire, two methods of internal reliability and test-retest reliability were used. In this sense, Cronbach’s alpha was calculated as the measure of internal reliability. Cronbach’s alpha equal to and above 0.7 was considered the minimum acceptable value. To measure the test-retest, 50 old adults (aged 60 years old and above) were asked to answer the questionnaire twice at a two-week interval. Then, the Pearson correlation coefficient was calculated between the two sets of scores. Also, the receiver operating characteristic (ROC) curve was utilized for specifying its sensitivity, specificity, and cut -off point
Results: Based on the comments of the expert panel, CVI scores of all questionnaire items were above 0.78, whereas four items rated less than 0.78 in terms of CVR scores; and, consequently, were removed from the questionnaire. Moreover, according to the reliability assessment results, both internal correlation and test-retest scores obtained acceptable values. Specifically, Cronbach’s alpha coefficient for usefulness, satisfaction, ease of use, and ease of learning were 0.771, 0.862, 0.756, and 0.798, respectively. In the ROC curve, the cut-off point was reported as 4.88 with the sensitivity and specificity of 97.8% and 75%, respectively, and area under the ROC curve at this cut-off point was obtained 81%.
Conclusion: Comparing a product’s characteristics with standards is a prerequisite to determining the level of usability of that product. The Farsi version of the USE questionnaire is a reliable tool for measuring usability with satisfactory validity and reliability. This questionnaire can be used in future studies in smartphone usability.

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Introduction: Usability is a criterion that indicates a product’s applicability and ease of use. A usable product allows the user to perform a task correctly and quickly, preventing errors and fatigue. The present study aimed to determine the ergonomic usability of the Zanjan University of Medical Sciences website of educational management system from the students’ viewpoint in 2019 and 2020.
Material and Methods: This cross-sectional study evaluated the usability of one of the websites for educational management systems using a standard questionnaire. The study examined the utility of web-based applications in the research processes automation field. The questionnaire was embedded in Google Forms and emailed to Zanjan University of Medical Sciences students, 404 of which returned. The data were analyzed with a 0.05 confidence level using SPSS software version 16.
Results: The 404 participants’ data showed that among the questionnaire nine factors, the highest and intermediate-range mean were for “Ease of Use” at 19 and 4 and for “Ease of Learning” at 18 and 4. Moreover, they were 13 and 3 for “System Capabilities,” 13 and 2 for “System Usability,” and 10 and 2 for “User Satisfaction.” In addition, “Errors Management” received 10 and 2, “Display” 10 and 2, “System Terms and Information” 8 and 2, and “User Environment Personalization” 5.5 and 3 as their highest and intermediate-range mean, respectively. Most questionnaires did not differ significantly depending on the age variable, meaning that different age groups had similar answers to most factors. The two sexes showed a significant difference in the responses to the “Usefulness of the System,” “Ease of Learning,” and “Display.” A significant difference for other factors was found in examining the relationship between educational level and the questionnaire factors. However, the “Error Management” and “Display” factors did not significantly differ, considering the educational levels.
Conclusion: The results showed that more attention should be paid to ease of use and learning in re-designing this website. However, it is necessary to consider all factors affecting usability.

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Introduction: The safety harness is a critical device for preventing falls from height, particularly in the construction industry. This study aimed to identify the factors contributing to the non-use of safety harnesses during work at height and to evaluate the comfort, satisfaction, and usability of these harnesses among construction workers in Tehran using a custom-designed tool.
Material and Methods: A semi-structured interview was conducted with construction workers to identify the factors influencing the non-use of safety harnesses. The collected data were analyzed using MAXQDA 10 software. Based on the results, which revealed dissatisfaction with the current safety harnesses, the levels of comfort, satisfaction, and usability were assessed using the Safety Harness Usability and Comfort Assessment Tool (SHUCAT) questionnaire.
Results: The reasons for not using safety harnesses were categorized into four main groups: management factors, worker attitudes, comfort, and harness design. These were further subdivided into 27 subgroups. The average satisfaction and comfort scores for safety harnesses were 26.8 ± 6.25, indicating that workers generally felt uncomfortable and dissatisfied with their harnesses. The average usability score was 38.70 ± 5.60, reflecting poor usability of the harnesses.
Conclusion: Improving the safety harness design could enhance workers’ comfort and satisfaction, increasing their willingness to use the equipment. Incorporating feedback from users and experts into the design process can help address the identified shortcomings and result in better product development.