A novel framework for human factors analysis and classification system for medical errors (HFACS-MES)-A Delphi study and causality analysis

The healthcare system (HCS) is one of the most crucial and essential systems for humanity. Currently, supplying the patients' safety and preventing the medical adverse events (MAEs) in HCS is a global issue. Human and organizational factors (HOFs) are the primary causes of MAEs. However, there are limited analytical methods to investigate the role of these factors in medical errors (MEs). The aim of present study was to introduce a new and applicable framework for the causation of MAEs based on the original HFACS. In this descriptive-analytical study, HOFs related to MEs were initially extracted through a comprehensive literature review. Subsequently, a Delphi study was employed to develop a new human factors analysis and classification system for medical errors (HFACS-MEs) framework. To validate this framework in the causation and analysis of MEs, 180 MAEs were analyzed by using HFACS-MEs. The results showed that the new HFACS-MEs model comprised 5 causal levels and 25 causal categories. The most significant changes in HFACS-MEs compared to the original HFACS included adding a fifth causal level, named "extra-organizational issues", adding the causal categories "management of change" (MOC) and "patient safety culture" (PSC) to fourth causal level", adding "patient-related factors (PRF)" and "task elements" to second causal level and finally, appending "situational violations" to first causal level. Causality analyses among categories in the HFACS-MEs framework showed that the new added causal level (extra-organizational issues) have statistically significant relationships with causal factors of lower levels (Φc≤0.41, p-value≤0.038). Other new causal category including MOC, PSC, PRF and situational violations significantly influenced by the causal categories of higher levels and had an statistically significant effect on the lower-level causal categories (Φc>0.2, p-value<0.05). The framework developed in this study serves as a valuable tool in identifying the causes and causal pathways of MAEs, facilitating a comprehensive analysis of the human factors that significantly impact patient safety within HCS.

Validity of ten analytical heat stress indices in predicting the physiological parameters of people under various occupational and meteorological conditions

Until now, only a few comprehensive studies have validated analytical heat stress indices in different conditions. The present study aims to investigate the validity of these indicators in predicting the physiological parameters of workers. This cross-sectional study was conducted with 194 male employees working in warm environments. First, demographic information was collected. After participants rested for 30 min, their heart rate and tympanic temperature were measured. The subjects then performed their routine tasks. At the end of 90 min, their heart rate and tympanic temperature were again measured. Additionally, their metabolism rate and clothing thermal insulation were estimated. Environmental parameters were also measured at 30-, 60-, and 90-min time points. Additional information required to compute the indices was recorded. Then, the values of each of the indices were computed. Finally, the validity of the indices was assessed under different conditions. The results indicated that the highest regression coefficients with tympanic temperature were assigned to modified physiologically equivalent temperature (mPET) (0.7515), predicted heat strain (PHS) (0.7201), and predicted mean vote (PMV) (0.7082), index, respectively. Also, the greatest regression coefficients with heart rate belonged to mPET (0.7773), PMV (0.7624), and PHS (0.6479) index, respectively. Based on the results, the highest diagnostic accuracies of receiver operating characteristic (ROC) curves for tympanic temperature were related to indices of mPET, PHS, and PMV with the area under the ROC curve (AUC) of 0.945, 0.931, and 0.930, respectively. Of the studied indices, it was observed that mPET, PHS, PMV, and PPD showed more validity compared to others.

Application of "Human Factor Analysis and Classification System" (HFACS) Model to the Prevention of Medical Errors and Adverse Events: A Systematic Review

Hospitals, as one of most important subsectors in human societies, are responsible for providing safe and effective medical services to clients. But sometimes these hospitals are the source of injury and death in patients by creating medical errors. In this systematic review study, the application of human factor analysis and classification system (HFACS) method in the classification of medical errors was investigated. Major electronic databases including Scopus, Web of Science, and MEDLINE were searched. All studies that investigated the application of HFACS method for coding, causation, and classification of medical errors and adverse events conducted from 2001 until February 2021 were included. A total of 108 articles were found. Due to duplication, 18 studies were removed from the review list. After reading the titles and abstracts, 50 of these publications were excluded because they had objectives different from this review. The remaining 40 publications were retrieved for further assessment. Of these, 28 publications were excluded because it did not meet the inclusion criteria. Finally, 12 articles remained for the final systematic review. We found that in 65% of the selected studies, preconditions for unsafe acts have been the major causal level of medical errors and adverse events. In the majority of the studies, communication and coordination, adverse mental states, physical environment, crew resource management, and technological environment have also been recognized as the most important causal categories in this study. As a result, to prevent medical errors and adverse events, the main focus should be on controlling the preconditions for unsafe acts including personnel factors, operator conditions, and environmental factors.

Effect of air blowing inside isolated hospital clothing on perceptual and physiological heat strain in laboratory conditions

Heat stress is one of the most common complaints of health care employees who wear isolation gowns to protect themselves from biological agents, particularly during the warmer seasons. This study was conducted in a climatic chamber to determine the influence of airflow within isolated hospital gowns on physiological-perceptual heat strain indices. The experiment was conducted in three trials: regular clothes (CON), an impenetrable gown without air blowing (GO), and a gown with air blowing (GO + FAN) at temperature conditions of 27 °C and 25% relative humidity (RH). During the trial, physiological-perceptual response data were recorded for a half-hour on a treadmill at a speed of km/hr and a slope of 0% activity at 5-min intervals. The ASHRAE Likert scale was used to assess thermal comfort (TC), thermal sensation (TS), and skin wetness sensation (WS). As the results show, there was a significant difference in mean scores for TC and WS in both sexes when working in the CON, GO, and GO + FAN groups (P < 0.001). In women, the mean scores for TS, TC, and WS reduced considerably (P < 0.001) in the GO and GO + FAN in the amount of 10 and 12 CFM (20 [Formula: see text]/h), but in males, there was a statistically significant difference between mean scores (P < 0.001) in the GO + FAN at 12 CFM (20 [Formula: see text]/h) and 14 CFM (24 [Formula: see text]/h). Also, the greatest difference between the average heart rate, chest temperature, and temperature inside the clothes in women and men in the trials GO and GO + FAN was observed in the air flow 12 CFM and 14 CFM, respectively (P < 0.001). The usage of an air blower in isolated hospital clothes has been shown to influence physiological-perceptual parameters in men and women substantially. The existence of airflow in these gowns can improve safety, performance, and thermal comfort while also decreasing the risk of heat-related disorders.

Design and Validation of Novel Evaporative Local Cooling Coatings to Prevent Adverse Health Effects of Heat Exposure

Background

This study aimed to design and evaluate the cooling power of local cooling coats for the head, neck, ankles, and wrists.

Methods

Local cooling coatings were designed using Iranians workers' existing 50^th anthropometric percentile data. After immersing the cooling coats in water for 5 minutes, they were placed in a chamber at 30°C, 35°C, and 40°C and 30% and 60% humidity and 0.2-0.4 m/s air velocity for 120 minutes. The amount of water evaporation was measured by weighing each coat before and after entering the chamber, and then the cooling power of each coat was calculated based on the amount of water evaporation.

Results

The average cooling power of cooling coats with covering areas (two wrists 933.75 cm², two ankles 1467.37 cm² and head and neck 1270 cm²) that the total area of the cover is 3671.12 cm², i.e., about 20% of the body at 30% relative humidity in 30°C, 35°C and 40°C was 67, 77 and 89 watts, respectively. At the mentioned temperature and in 60% relative humidity, the cooling power was 34, 40, and 55 watts. As the relative humidity increased, the cooling power of the coats decreased.

Conclusions

Local evaporative cooling coat on the head, neck, wrists, and ankles can reasonably repel excess heat entering the body. The best performance of these coats is in hot and dry environments. Probably, if used in conjunction with cooling vests in environments with high temperatures and heavy activity, it can act as a supplement to cooling vests and have a significant effect on improving functions.

Assessing the students' readiness for E-Learning during the Covid-19 pandemic: A case study

The aim of this study was to scrutinize the E-learning readiness among the students of the Faculty of Health at Isfahan University of Medical Sciences during the Covid-19 pandemic. This study was conducted as a descriptive-analytic study on 165 the students of the Faculty of Health in Isfahan University of Medical Sciences in 2021. To examine the level of the participants' readiness for E-learning during the Covid-19 pandemic period, the questionnaire developed by Watkins et al, was administered. Finally, the data analysis was performed with SPSS₂₄ software. The results showed that the mean and standard deviation were 97.44 and 17.67, respectively. Only 1.2% of the participants had a low level of E-learning readiness. 27.9% were at the intermediate level and 70.9% were at the high level. Moreover, the results revealed that the participants had the highest degree of readiness in "Technology Access" and "Internet discussions" dimensions (0.79) and the lowest degree of readiness in "motivation" dimension (0.67). The results of this study indicated that the majority of the participants in this study had a high E-learning readiness, so the university can implement the virtual education. However, the students' learning motivation should be enhanced through providing the required infrastructure and holding training courses for the students specially the BA ones.

Development of an observational - perceptual heat strain risk assessment (OPHSRA) index and its validation

BACKGROUND

The thermal strain can be measured using subjective methods without the use of sensitive equipment. The purpose of the present study was the development and validation of an observational - perceptual heat strain risk assessment (OPHSRA) method.

METHODS

This cross-sectional study, in 2019, was performed. At first, an observational-perceptual questionnaire was designed using effective items in producing heat strain. Then, the reliability and validity of the questionnaire were examined. Later, 201 male workers were asked to perform the routine tasks for 90 min under various climatic conditions after resting in a cool room. At the end of the activity, the tympanic temperature of the subjects was accurately measured. Also, the designed questionnaire was completed by researchers and participants. Then, the effect coefficients of the items were calculated and used for developing the novel index. At final, the index validity was investigated.

RESULTS

The values of the content validity ratio (CVR), content validity index (CVI), and Cronbach's coefficient alpha (α) of the designed questionnaire with 16 questions were equal to 0.793, 0.913, and 0.910, respectively. The results indicated that environmental, job, administrative, and clothing items assessed by the questionnaire with the coefficients of 0.860, 0.658, 0.783, and 0.566 had significant effects on the thermal strain, respectively. These coefficients were exploited to develop the index. The result revealed that the OPHSRA index justified 69% of the variations of the tympanic temperature (R² = 0.69).

CONCLUSION

The novel index developed by the questionnaire had an acceptable validity. Therefore, this index can be used for estimating the risk of thermal strain in a variety of thermal conditions.

Investigating the Combined Effects of Heat and Light Color Temperature on Precision and Speed in Female Students in Laboratory Conditions

Background & Aims of the Study: Cognitive functions, such as precision and speed, significantly affect human errors and incidents. The temperature of light color and heat can impact cognitive functions. Therefore, the present study examined the effect of heat and color temperature on the speed and precision of work in the laboratory. Materials and Methods: This study was conducted on 10 female students in the Laboratory of Atmospheric Medical School of Isfahan University of Medical Sciences in Isfahan City, Iran. Piron v-vibrometer and precision and target vibrometer devices were used to measure accuracy and speed. The test was held in 4 turns, each time for 1 hour. The first turn, 22°C, and color temperature 3000°K, the second turn 22°C and color temperature 6000°K, the third turn 36°C and color temperature 3000°K and the fourth turn 36°C and color temperature 6000°K, adjusted. Results: Based on the obtained results, precision measurement with precision and target vibrometer was significant in two cases with a color temperature of 3000 and temperatures of 22°C and 36°C (P<0.05); thus, with increasing temperature, the frequency of errors enhanced, and consequently the precision decreased. Furthermore, the speed measurement with the precision and target and Piron v-vibrometer in color temperature state 6000 and temperatures of 22°C and 36°C and the color temperature of 3000 and temperatures 22°C and 36°C were significant (P<0.05). In other words, with increasing temperature, the time of work decreased, and as a result, the speed of work increased, and in other cases, no significant relationship was observed (P>0.05). Conclusion: In general, the present study results indicated that the precision of work at 36°C is less than exposure to 22°C; the speed of work is higher, and changing the color temperature of light has no significant effect on increasing the precision of work. Therefore, it is suggested to use control strategies to reduce the temperature in environments with temperatures higher than comfort.

Investigation of the effect of ergonomic flooring on the distribution of foot pressure in long standing

Introduction: Many occupations require prolonged standing during exercise, which is one of the most important causes of musculoskeletal disorders, causing pain and discomfort in the back, lower limbs, and especially the soles of the feet, resulting in improper distribution of pressure in the soles of the feet. Epidemiological studies also show a strong association between prolonged standing and pressure on the lower back and lower limbs. One of the ergonomic solutions to reduce the problems caused by long-standing activities is to correct the surface under the fee. Therefore, this study investigates the effect of ergonomic flooring and conventional flooring on the distribution of foot pressure in healthy individuals; based on that, the effect of using ergonomic flooring in comparison with conventional flooring, more appropriate distribution, and reduction of pressure in the sole can be determined. Materials and Methods: This descriptive-analytical study was performed on 16 students with a mean age of 27.87±7.31 and a body mass index of 24.15±4.31. According to previous comparative studies and data analysis obtained from pilot samples, by considering the 95% confidence interval, the samples were determined by the convenience sampling method. Each participant was measured at eight anatomical points for one hour at two different surfaces of ergonomic and ordinary floor. Foot pressure distribution using a pedar-x device while the volunteers were barefoot. Data were analyzed by paired t-test and Wilcoxon using SPSS software. Results: This study showed that the ergonomic flooring significantly reduced the mean pressure on the plantar pressure (p≤0.001). Also, there is a significant difference in the mean pressure of left and right legs in different anatomical points when using ordinary surfaces and flooring (p≤0.001). Conclusion: There is a difference between the distribution of plantar pressure in ergonomic flooring and conventional flooring. Ergonomic flooring has better distribution than the ground and reduces the pressure on the sole during static activities.

Development and validation of an environmental heat strain risk assessment (EHSRA) index using structural equation modeling based on empirical relations

Background

Need to a simple, available, accurate, comprehensive, and valid indicator is felt to assess thermal effects. Therefore, the present study was aimed to develop and validate the environmental heat strain risk assessment (EHSRA) index using structural equation modeling (SEM) based on empirical relations.

Methods

This cross-sectional study was performed on 201 male workers in environments with various climatic conditions. The heart rate and tympanic temperature of the individuals were monitored at times of 30, 60, and 90 min after beginning the work. At these times, values of dry temperature, wet temperature, globe temperature, and air velocity were also measured and metabolism rate and clothing thermal insulation value were estimated. At the end, a theoretical model was depicted in AMOS software and obtained coefficients were applied to develop a novel index. The scores of this indicator were categorized into four risk levels via ROC curves and validate using linear regression analysis.

Results

Indirect effect coefficients of the globe temperature, dry temperature, wet temperature, air velocity, metabolism, and clothing thermal insulation variables on the tympanic temperature were computed by 0.77, 0.75, 0.69, 0.24, 0.49, and 0.39, respectively. These coefficients were applied to develop the index. Optimal cut-off points of boundaries between risk levels included 12.02, 15.88, and 17.56. The results showed that the EHSRA index justified 75% of the variations of the tympanic temperature (R² = 0.75).

Conclusions

The novel index possesses appropriate validity. It was suggested that this indicator is applied and validated in various environments in the next studies.

Identification, Classification, and Prioritization of Effective Factors in Producing Thermal Strain in Men at Workplaces using Fuzzy AHP Technique

Background:

Various factors can affect thermal strain at workplaces. To prevent heat illnesses due to the heat strain, one must identify and prioritize these factors. Therefore, the present study was aimed to determine the relative importance of the effective factors in producing thermal strain in men at workplaces using fuzzy AHP technique.

Materials and Methods:

This qualitative practical study was performed in 2019. Effective factors in producing heat strain were identified by a literature review. Then, an expert panel reviewed the identified factors and omitted some of them. Further, the balance theory of job design was applied to classify the heat strain factors. Later, these factors were categorized into six groups, including environmental, personal, job, clothing, administrative, and lifestyle elements. In the end, the fuzzy analytical hierarchy technique was used for prioritizing the elements and factors involved in each of them.

Results:

Based on the results, the environmental element had the highest relative weight and priority (0.178). Other priorities were assigned to the job element (0.171), clothing element (0.171), personal element (0.169), administrative element (0.169), and lifestyle element (0.142), respectively.

Conclusion:

In general, the results showed that environmental factors are the most effective ones in producing heat strain. The results of the present study can be helpful in controlling the thermal strain.

The effect of cooling vests on physiological and perceptual responses: a systematic review

Humans in hot environments are exposed to health risks and thermal discomfort which seriously affect their physical, physiological and mental workload. This study aimed to assess the effects of using cooling vests (CVs) on physiological and perceptual responses in the workplace. Three main databases were searched using subject headings and appropriate Mesh terms. The article has been written according to the preferred reporting items for systematic reviews checklist. A total of 23,837 studies were identified for screening and 63 studies were eligible for data extraction. A statistically significant difference was observed in body temperature among hybrid cooling garments (HBCGs), phase-change materials (PCMs) and air-cooled garments (ACGs) at 31.56-37 °C (60% relative humidity), evaporative cooling garments at 25.8-28.1 °C and liquid cooling garments at 35 °C (49% relative humidity) compared to without CVs (p < 0.001). HBCGs (PCMs and ACGs) are effective means in hot, moderate, humid or dry environments.

Development of a personal heat strain risk assessment (PHSRA) index in workplaces and its validation

BACKGROUND

There is not a comprehensive heat stress index to screen the people susceptible to heat disorders and illnesses in hot workplaces. The present study was aimed to develop a personal heat strain risk assessment (PHSRA) index in workplaces and validate it.

METHODS

This cross-sectional study was carried out on 201 Iranian male employees under various thermal conditions. At first, the demographical data of participants were gathered. After that, the heart rate and tympanic temperature of the subjects were carefully measured at times of 30, 60, and 90 min of starting the work. Environmental factors were measured simultaneously. The metabolism rate and insulation value of clothes were also estimated. At the end, a novel index of the heat strain was developed using structural equation modeling in AMOS and validated using linear regression analysis in SPSS.

RESULTS

Indirect effect coefficients of personal factors including age, body mass index, maximum aerobic capacity, and body surface area were equal to 0.031, 0.145, - 0.064, and 0.106, respectively. The coefficients of main factors including dry temperature, wet temperature, globe temperature, wind speed, metabolism, and clothing thermal insulation were obtained as 0.739, 0.688, 0.765, 0.245, 0.482, and 0.383, respectively. These coefficients and normalized values of the factors were used to develop a novel index. The total score of the index was categorized into four levels by optimal cut-off points of 12.93, 16.48, and 18.87. Based on the results of regression analysis, this index justifies 77% of the tympanic temperature as a dependent variable (R2 = 0.77).

CONCLUSIONS

In general, the results indicated that the novel index developed by the personal and main factors had proper validity in the prediction of thermal strain.

Evaluating combined effect of noise and heat on blood pressure changes among males in climatic chamber

INTRODUCTION

Exposure to noise and heat causes individuals to experience some changes in the function of cardiovascular system in workplaces. This study aimed to find the combined effect of heat and noise on systolic and diastolic types of blood pressure in experimentally controlled conditions.

METHODS

This quasi-experimental study was performed with 12 male students in a climatic chamber in 2014. Blood pressure including systolic and diastolic was measured in the following conditions: 15 min after rest in exposure to heat (40°C, relative humidity [RH]: 30%), exposure to noise with 75, 85, and 95 dB rates in thermal comfort condition (22.1 ± 0.9 wet-bulb globe temperature), and combined exposure to heat (40°C, RH: 30%) and noise with 75, 85, and 95 dB. Friedman test was used to analyze the data.

RESULTS

The mean change of systolic blood pressure was different significantly before and after exposure to heat and noise levels including 75, 85, and 95 dB (P = 0.015, P = 0.001, P > 0.001, P = 0.027, respectively). Although systolic and diastolic blood pressures changed drastically, it was not significantly different in simultaneous exposure to heat and noise.

CONCLUSION

Both systolic and diastolic blood pressures decreased in exposure to heat, while exposure to different levels of noise elevates systolic and diastolic blood pressures. However, when exposed to a combination of heat and noise, subtle changes of blood pressure were traced, which can be characterized as average, considering heat-only and noise-only tension situations.

Performance evaluation of Iranian cooling vest on the physiological indices in hot climatic chamber

BACKGROUND

Heat stress is a threat to those who work in high temperatures. The purpose in this study was an examination of the cooling ability of Iranian phase change material (PCM) cold vest in hot and dry conditions in a climatic chamber.

MATERIALS AND METHODS

This experimental study was implemented on 12 male students (age 23.7 ± 2.8 years, weight 66.1 ± 11.4 kg, and VO2 max 2.53 L/min) in 2013. The heat strain score index (HSSI), skin temperature and oral temperature, and heartbeat in two phases with and without cooling vest was measured during 30 min in a climatic chamber (temperature 38.8 ± 1.3°C humidity ratio 32.9 ± 2.3%) and in two activity intensity of 2.4 and 4.8 km/h speed on the treadmill, and the data differences between groups "with" and "without" vest were tested by t-test and repeated measurement. The level of significance was considered as 0.05.

RESULTS

The change in heartbeat at two activities, the oral temperature and heat strain score at 4.8 km/h, did not differ significantly between groups (with and without vest), as expected (P > 0.05). However, the change in skin temperature at two activities, oral temperature and heat strain score at 2.4 km/h, was significant between groups, as expected (P < 0.05). The average of skin temperature at 15(th) and 30(th) min during the experiment at two activities of 2.4 and 4.8 km/h was significant.

CONCLUSION

The findings of the study indicated that using the Iranian PCM cold vest in hot and dry climate can affect the reduction of skin temperature, oral temperature, and HSSI in light activities.

Designing of the Cooling Vest from Paraffin Compounds and Evaluation of its Impact Under Laboratory Hot Conditions

Background:

The phase change materials (PCMs) have the appropriate properties for controlling heat strain. One of the well-known PCMs is paraffin. This study aimed to design the cooling vest from the cheap commercial paraffin compound and evaluation of its effectiveness under laboratory hot conditions.

Methods:

the cooling vest was made of the polyester fabric and it had 17 aluminum packs. The each of aluminum packs was filled by 135 g of prepared paraffin with a proper melting point in the range of 15–35°C. an experimental study was conducted on ten male students under warm conditions (air temperature = 40°C, relative humidity = 40%) in a climatic chamber. Each participant was tested without cooling vest and with cooling in two activities rate on treadmill to include: light (2.8 km/h) and moderate (4.8 km/h). The time of this test was 30 min in each stage. During the test, the heart rate, the oral temperature, the skin temperature were measured every 4 min. Finally, data were analyzed using the Kolmogrov–Smirnov and repeated measurement ANOVA test in SPSS 16.

Results:

The latent heat of the prepared paraffin compound and the peak of the melting point were 108 kJ/kg and 30°C, respectively. The mean and standard deviation of heart rate, oral temperature, and skin temperature with cooling vest in light activity were 103.9 (12.12) beat/min, 36.77 (0.32)°C, and 31.01 (1.96)°C and in moderate activity were 109.5 (12.57) beat/min, 36.79 (0.20)°C, and 29.69 (2.23)°C, respectively. There is a significant difference between parameters with a cooling vest and without cooling (P < 0.05).

Conclusions:

The designed cooling vest with low cost can be used to prevent thermal strain and to increase the physiological stability against the heat. However, the latent heat of this cooling vest was low.

Relationship of Environmental, Physiological, and Perceptual Heat Stress Indices in Iranian Men

Background:

Heat stress is a known occupational hazard, which cause reduced exercise capacity. The purpose of this study was to evaluate the relationship among environmental, physiological, and perceptual heat stress indices in Iranian men.

Methods:

This analytical study was carried out on 24 healthy men (age 23.34 ± 1.64 years) with normal body weight (body mass indices 21–25 kg/m²) in low workload for 120 min under hot climates (22–32°C, 40% relative humidity). Physiological strain index (PSI), wet-bulb globe temperature (WBGT), oral temperature, heart rate (HR), and heat strain score index (HSSI) questionnaires were simultaneous measurements taken at any 5 min during the exposure and resting state the initial measurements.

Results:

The results showed that the range of WBGT index was 20.47–31.40°C. Significant correlation were found among WBGT and HSSI (r = 0.995), PSI (r = 0.990), oral temperature (r = 0.991), and HR (r = 0.972) indices. Also, significant correlation were found among HSSI and oral temperature (r = 0.983), HR (r = 0.978), and PSI (r = 0.987).

Conclusions:

The results have shown that simultaneous with the increase in valid indices of heat stress such as WBGT and PSI indices, the amount of HSSI has also increased with high power. Therefore, when there is no access to a reliable heat stress method such as WBGT, or PSI indices, HSSI, an observative and subjective heat strain method, can be used as a simple, fast in least 5 min, and inexpensive for evaluating the heat strain in Iranian men.

A survey of the relationship between work schedule and its effect on the fatigue of rescue personnel in Isfahan with a standard method of CIS202

CONTEXT

Fatigue is a factor that can have negative effects on family life, social relationship and work. Work schedule is one of the affective factors on personnel's fatigue in different jobs. In this study, the work schedule and its effect on rescue personnel in Isfahan are explored.

AIMS

The purpose of this study was to investigate the relationship between work schedules and fatigue among rescue personnel.

SETTINGS AND DESIGN

This study is periodical and has been conducted on 72 employees of rescue personnel in Isfahan.

MATERIALS AND METHODS

Random sampling was done and the primary data that was collected through fatigue assessment questionnaire after being conducted as a pilot study on 10% of samples were collected to confirm the validity of this study. Finally, the data was given to SPSS11.5 software and were analyzed by descriptive statistics and linear digression.

RESULTS

The results showed that from the statistical point of view some parts of work schedules like work hours satisfaction, resting time and work order on total fatigue are effective in linear and inverse way but the item "predictibility of work conditions" does not have a meaningful relationship with total fatigue. Furthermore, the results showed that there is a meaningful and inverse relationship with work hours, resting time and work order with mental fatigue and also the work schedule has a meaningful, linear and inverse relation with mental fatigue and total fatigue.

CONCLUSIONS

By increasing the satisfaction of working hours, increasing resting time and also with an increase of work order the total fatigue of rescue personnel will decrease.

Validation of Perceptual Strain Index to Evaluate the Thermal Strain in Experimental Hot Conditions

Background:

The incidence of heat stress is one of the most common problems in workplaces and industries. Many heat stress indices have been developed, and these indices have some disadvantages. The purpose of this study is to validate the perceptual strain index (PeSI) in experimental hot conditions.

Methods:

This study is of cross-sectional carried out on 15 men at five different thermal conditions (35°C, 30°C, 27°C, 24°C, and 21°C) in a climate chamber and on a treadmill at three levels of light (2.4 kph), medium (4.8 kph) and heavy activity (6.3 kph). Heart rate and oral temperature were respectively measured to calculate the physiological strain index. Also, thermal sensation and rate perceive exertion were respectively measured to calculate the PeSI. Finally, the correlation between the indices was analyzed using Pearson correlation test and regression analysis.

Results:

Pearson correlation test showed a high correlation (r = 0.94) between the PeSI and physiological strain index (P = 0/001). It was also observed a high correlation between the PeSI and the oral temperature (r = 0.78, P = 0/001) and the heart rate (r = 0.90, P = 0/001). In addition, there was found a moderate correlation (r = 0.71) between the PeSI and the wet bulb glob temperature (P = 0/001). However, there was no correlation between the PeSI and the body mass index (r = 0.0009, P = 0.79).

Conclusions:

The research findings showed when there is no access to other forms of methods to evaluate the heat stress, it can be used the PeSI in evaluating the strain because of its favorable correlation with the thermal strain.

Development and Validation of a Questionnaire for Preliminary Assessment of Heat Stress at Workplace

BACKGROUND

Current heat stress indices are not completely suitable for heat strain screening in developing countries due to their inherent and applied limitations. The aim of this study was development of a questionnaire method entitled "Heat Strain Score Index" (HSSI) in order to perform a preliminary assessment of heat stress at work.

METHODS

This research included six phases (i) Item generation (ii) Content validity (iii) Reliability analysis (iv)Structure validity (v) Concurrent validity and (vi) Classification of thermal risk level. In item generation phase, 40 items were identified to have impact on the heat strain. Content validity was evaluated by occupational health specialists.

RESULTS

In consistency assessment, Cronbach's coefficient (α) of items was 0.91. Exploratory factor analysis on items HSSI draft identified four subscales which explained 71.6% of the variance. Correlation between the HSSI score with aural temperature was 0.73. Cut-off point; sensitivity and specificity for upper no thermal strain zone were 13.5, 91% and 50%, respectively. Whereas Cut-off point, sensitivity and specificity for lower thermal strain zone were 18, 86% and 73%.

CONCLUSIONS

The results showed that 18 variables that were measurable through subjective judgment and observation in the HSSI scale covered heat stress key factors. This scale demonstrated reliability and initial validity in scale were suitable. Therefore HSSI scale for primary evaluation heat stress is appropriate.

The Effect of Fabric Type of Common Iranian Working Clothes on the Induced Cardiac and Physiological Strain Under Heat Stress

The present study compared the effect of fabric type of working clothes on heat strain responses in different levels of physical workload and under different kinds of weather conditions. Four kinds of working clothing fabric that are greatly popular in Iranian industry were assessed on 18 healthy male at 2 environments: hot and humid (dry temperature [DBt]: 35°C and relative humidity [RH]: 70%) and hot and dry (DBt: 40°C and RH: 40%). The physiological responses such as heart rate and core body temperature were reported. It was found that there were no significant differences between different types of clothing fabric on cardiac and physiological parameters. It can be recommended that 100% cotton clothing ensemble during low-workload activities and 30.2% cotton-69.8% polyester clothing ensemble during moderate-workload activities is used for Iranian workers to maintain the cardiac and physiological strains as low as possible.

The effects of state anxiety and thermal comfort on sleep quality and eye fatigue in shift work nurses

Psychological problems as state anxiety (SA) in the work environment has negative effect on the employees life especially shift work nurses, i.e. negative effect on mental and physical health (sleep quality, eye fatigue and comfort thermal). The purpose of this study was determination of effects of state anxiety and thermal comfort on sleep quality and eye fatigue in shift work nurses.

METHODS

This cross-sectional research conducted on 82 shift-work personnel of 18 nursing workstations of Isfahan hospitals in 2012. To measure the SA, sleep quality, visual fatigue and thermal comfort, Spielberger state-trait anxiety inventory, Pittsburg sleep quality index, eye fatigue questionnaire and thermal comfort questionnaire were used respectively. The data were analyzed with descriptive statistics, student test and correlation analysis.

RESULTS

Correlation between SA and sleep quality was -0.664(P < 0001), Pearson correlation between SA and thermal comfort was -0.276(P = 0.016) and between SA and eye fatigue was 0.57 (P < 0001).

CONCLUSION

Based on these results, it can be concluded that improvement of thermal conditions and reduce state anxiety level can be reduce eye fatigue and increase the sleep quality in shift work nurses.

Study of the relationship between the aerobic capacity (VO2 max) and the rating of perceived exertion based on the measurement of heart beat in the metal industries Esfahan

BACKGROUND AND OBJECTIVE

To establish a balance between work (physical exercise) and human beings, the aerobic capacity (VO2 max) could be used as a measure. Additionally, the subjective and physiological assessment could be applied as one of the methods for assessing physical exercise. The most commonly used tools for the assessment of fatigue during physical exercise include the Borg scale Rating of perceived Exertion (RPE) in relation to subjective symptoms and heart rate (HR) in relation to physiological symptoms. The study is aimed to investigate the relationship between the aerobic capacity and the RPE based on the measurement of heat rate (HR) of workers from the Metal Industries of Isfahan.

MATERIALS AND METHODS

The subjects were 200 male workers from metal components manufacturers in Isfahan selected by using random sampling based on statistic method. The subjects were examined by using ergometer in accordance with A strand 6 minutes cycle test protocol. Furthermore, the subjects were asked to rate their status based on the Borg rating scale at the end of each minute. Additionally, their heat rates were monitored and recorded automatically at the end of each minutes.

RESULTS

Statistical analysis showed that there was a significant relationship between the RPE and the aerobic capacity (VO2 max) (r = -0.904, P < 0.05). The results illustrated that there was a stronger correlation between HR and VO2 max (r = 0.991, P < 0.001). The regression analysis of the quadratic equation also indicated that there was also a significant relationship between the VO2 max and HR.

CONCLUSIONS

The results indicated that there was a strong relationship between the RPE and VO2 max, as well as a greater correlation between HR and VO2 max. Therefore, the HR could be used as a Prediction measure to estimate VO2 max.

Effects of work-related stress on work ability index among refinery workers

INTRODUCTION

Work-related stress is one of the basic problems in industrial also top 10 work-related health problems and it is increasingly implicated in the development a number of problems such as cardiovascular disease, musculoskeletal diseases, early retirement to employees. On the other hand, early retirement to employees from the workplace has increased on the problems of today's industries. Hereof, improving work ability is one of the most effective ways to enhance the ability and preventing disability and early retirement. The aim of This study is determine the relationship between job stress score and work ability index (WAI) at the refinery workers.

MATERIALS AND METHODS

This is a cross-sectional study in which 171 workers from a refinery in isfahan in 2012 who were working in different occupational groups participated. Based on appropriate assignment sampling, 33 office workers, 69 operational workers, and 69 maintenance workers, respectively, were invited to participate in this study. Two questionnaires including work related-stress and WAI were filled in. Finally, the information was analyzed using the SPSS-20 and statistic tests namely, analysis of covariance Kruskal-Wallis test. Pearson correlation coefficient, ANOVA and t-test.

RESULTS

Data analysis revealed that 86% and 14% of participants had moderate and severe stress respectively. Average score of stress and standard deviation was 158.7 ± 17.3 that was in extreme stress range. Average score and standard deviation of WAI questionnaire were 37.18 and 3.86 respectively. That placed in a good range. Pearson correlation coefficient showed that WAI score had significant reversed relationship with a score of stress.

CONCLUSION

According to the results, mean stress score among refinery worker was high and one fator that affect work abiity was high stress, hence training on communication skills and safe working environment in order to decreses stress, enhance the work ability of workers.

Cardiac strain comparison between workers with normal weight and overweight in the hot humid weather of the Persian Gulf region

BACKGROUND

In the hot weather, overweight and obesity are considered as significant risk factors for the incidence of cardiac strain in workers. This study is aimed at comparing the cardiac strain among overweight and normal-weighted workers, in the hot, humid conditions of the south of Iran.

MATERIALS AND METHODS

This cross-sectional study was conducted on 71 workers in the south of Iran, in the summer of 2010. The heart rate was measured at rest and at actual work. Cardiac strain based on the working heart rate (WHR), the relative cardiac cost (RCC), the net cardiac cost (NCC), the load relative cardiovascular (CVL), and heart rate reduction were analyzed in 35 normal weight people (BMI <25) and 36 people who were overweight (BMI >25), using descriptive statistics and t- tests.

RESULTS

In 42% of the total workers, the body mass index was more than 25. The average temperature of the two groups was not significantly different. The mean WHR in these two groups was 101 ± 20.3 and 112 ± 18.9, respectively (P = 0.026). Percentages that exceeded the acceptable limits in parameters of NCC, RCC, WHR, CVL, and the Brouha index, were significantly higher in overweight people than those in people with normal weight.

CONCLUSIONS

Based on the study results, the severity of cardiac strain was higher in overweight workers when compared with normal weight workers. Hence, in order to decrease the cardiac strain, selecting overweight individuals for these jobs should be avoided, as also some vital intervention for losing weight, such as, nutrition education and encouraging them to increase their physical activity, should be implemented.

Validation of a questionnaire for heat strain evaluation in women workers

INTRODUCTION

Physiological, anthropometrical and thermal perceptual are the most important factors affecting thermoregulation of men and women in workplaces. The purpose of this study was determining the validity of a questionnaire method for assessing women's heat strain in workplaces.

METHODS

This cross-sectional study was carried out on 96 healthy women. Data were continuously collected over a period of 3 months (July-September) in 2012. Mean ± (SD) of age was found to be 31.5 ± 7.48 years, of height 1.61 ± 0.05 m, of weight 61.55 ± 10.35 kg, and of body mass index 23.52 ± 3.75 kg/m(2) in different workplaces. Heart rate and oral temperature were measured by heart rate monitoring and a medical digital thermometer, respectively. Subjects completed a draft questionnaire about the effective factors in the onset of heat strain. After collecting the questionnaires, the data were analyzed by applying Cronbach'sa calculation, factor analysis method, Pearson correlation and receiver operator characteristic curves using the SPSS 18 software.

RESULTS

The value for Cronbach's α was found to be 0.68. The factor analysis method on items of draft questionnaire extracted three subscale (16 variables) which they explained 63.6% of the variance. According to the results of receiver operator characteristic curve analysis, the cut-off questionnaire score for separating people with heat strain from people with no heat strain was obtained to be 17.

CONCLUSIONS

The results of this research indicated that this quantitative questionnaire has an acceptable reliability and validity, and a cut-off point. Therefore it could be used in the preliminary screening of heat strain in women in warm workplaces, when other heat stress evaluation methods are not available.

Evaluation of the effect of noise on the rate of errors and speed of work by the ergonomic test of two-hand co-ordination

BACKGROUND

Among the most important and effective factors affecting the efficiency of the human workforce are accuracy, promptness, and ability. In the context of promoting levels and quality of productivity, the aim of this study was to investigate the effects of exposure to noise on the rate of errors, speed of work, and capability in performing manual activities.

METHODS

This experimental study was conducted on 96 students (52 female and 44 male) of the Isfahan Medical Science University with the average and standard deviations of age, height, and weight of 22.81 (3.04) years, 171.67 (8.51) cm, and 65.05 (13.13) kg, respectively. Sampling was conducted with a randomized block design. Along with controlling for intervening factors, a combination of sound pressure levels [65 dB (A), 85 dB (A), and 95 dB (A)] and exposure times (0, 20, and 40) were used for evaluation of precision and speed of action of the participants, in the ergonomic test of two-hand coordination. Data was analyzed by SPSS18 software using a descriptive and analytical statistical method by analysis of covariance (ANCOVA) repeated measures.

RESULTS

The results of this study showed that increasing sound pressure level from 65 to 95 dB in network 'A' increased the speed of work (P < 0.05). Increase in the exposure time (0 to 40 min of exposure) and gender showed no significant differences statistically in speed of work (P > 0.05). Male participants got annoyed from the noise more than females. Also, increase in sound pressure level increased the rate of error (P < 0.05).

CONCLUSIONS

According to the results of this research, increasing the sound pressure level decreased efficiency and increased the errors and in exposure to sounds less than 85 dB in the beginning, the efficiency decreased initially and then increased in a mild slope.

The molecular and morphological variations of Culex pipiens complex (Diptera: Culicidae) in Iran

BACKGROUND & OBJECTIVES

Taxonomic status of Culex pipiens is well-known as many years with such a wide variety of morphological and biological characteristics. These changes have been the subject of extensive investigation by many researchers. There are a little information about the morphology and molecular data of Cx. pipiens complex in Iran. The taxonomic status of the complex is very important because of medical and veterinary importance and wide distribution in the country.

METHODS

This study was carried out in 11 areas in Iran using dipping technique from April 2009 to October 2010. Molecular study was carried out using primers F1457 as forward and B1256 as reverse, which amplified Ace.2 gene and performed PCR-RFLP using ScaI restriction enzyme.

RESULTS

Culex quinquefasciatus found in south to central areas of Iran and reported as sympatric with Cx. pipiens in the central regions. Culex pipiens distributed in many areas of the country. Sequencing alignment of Ace.2 gene of Cx. quinquefasciatus and Cx. pipiens showed 6.5% variation in 46bp, especially in intron locus of gene. Culex pipiens complex from Iran are located in two separate clades with sister branches using phylogenetic sequencing tree.

INTERPRETATION & CONCLUSION

The male genitalia found as the most reliable diagnostic characters for identification of Cx. pipiens complex in Iran that confirmed by amplify the Ace.2 gene in the samples but we recommended the use of sequencing PCR products of microsatellite loci and COI gene in future study.

The relationship between thermal comfort and light intensity with sleep quality and eye tiredness in shift work nurses

Environmental conditions such as lighting and thermal comfort are influencing factors on sleep quality and visual tiredness. The purpose of this study was the determination of the relationship between thermal comfort and light intensity with the sleep quality and eye fatigue in shift nurses.

METHOD

This cross-sectional research was conducted on 82 shift-work personnel of 18 nursing workstations in Isfahan Al-Zahra Hospital, Iran, in 2012. Heat stress monitoring (WBGT) and photometer (Hagner Model) were used for measuring the thermal conditions and illumination intensity, respectively. To measure the sleep quality, visual tiredness, and thermal comfort, Pittsburg sleep quality index, eye fatigue questionnaire, and thermal comfort questionnaire were used, respectively. The data were analyzed with descriptive statistics, Student's t-test, and Pearson correlation.

RESULTS

Correlation between thermal comfort which was perceived from the self-reporting of people with eye tiredness was -0.38 (P = 0.002). Pearson correlation between thermal comfort and sleep quality showed a positive and direct relationship (r = 0.241, P = 0.33) but the correlation between thermal comfort, which was perceived from the self-reporting of shift nurses, and WBGT index was a weak relationship (r = 0.019).

CONCLUSION

Based on the obtained findings, it can be concluded that a defect in environmental conditions such as thermal conditions and light intensity and also lack of appropriate managerial plan for night shift-work nurses are destructive and negative factors for the physical and mental health of this group of practitioners.

A Study on Work Ability Index and Physical Work Capacity on the Base of Fax Equation VO(2) Max in Male Nursing Hospital Staff in Isfahan, Iran

BACKGROUND

The purpose of this research is to establish the ability of employees by work ability index (WAI), physical work capacity (PWC), and finding the correlation between them. Establishing the PWC index with attention to WAI values for the purpose of saving in costs and time of PWC measurements is another aim of this project.

METHODS

The present research is an analytic cross-sectional and one-trail study. The study population consists of 228 randomly selected registered nurses from hospitals in Isfahan (Iran). The WAI and PWC were established through WAI questionnaire and Fax equation and by using ergometer bicycle, respectively. The resulting data were analyzed using SPSS 16 software.

RESULTS

Average WAI and PWC among the study population were 38.25±4.4 and 4.45±0.7, respectively. Pearson test results showed no significant correlation between PWC and WAI in different age groups (r=0.3 and P>0.05). Multiple linear regression analysis showed that the variables of age and diagnosed diseases were the most effective factors of WAI (β=0.18 and P>0.05). Pearson test revealed a significant correlation between the number of diagnosed diseases and PWC index in age groups of 40-49 years.

CONCLUSION

Average WAI in this research, like other studies on similar jobs is in the acceptable level of >36. Work ability index and PWC index in different age groups did not show a significant correlation and this suggests that there are essential discrepancies in work ability evaluations made by each index and it is not possible to predict PWC index using WAI values. Given the PWC results and the level of nursing staff's activity (low, medium) the WAI is a suitable instrument to establish the professionals' abilities. This study revealed that 27.6% of individuals were subject to medium-low work ability risk (WAI<37), which was 1.8 times that of Finland's professional health Institute, which could be caused by shift working and increased working hours.

The Morphological Variations of Culex pipiens Larvae (Diptera: Culicidae) in Yazd Province, Central Iran

BACKGROUND

Culex pipiens complex shows variations in morphological and biological characters including different biological forms and has medical and veterinary importance. Because of having morphological variations, sometimes it is not easy to separate this species from Cx. quinquefasciatus and Cx. torrentium. The aim of this study was to identify the Culex pipiens complex species in order to use in control programs in the future.

METHODS

This study was carried out in two randomly selected rural villages in Yazd County, eastern Iran using dipping technique from April to October 2009. The data were analyzed using SPSS software version 16.

RESULTS

Average of siphon index in fourth-instrar larvae was 3.86±0.03, the minimum and maximum were calculated 2.43 and 5.14, respectively. Siphon/Saddle index was measured as average, minimum and maximum 3.2±0.2, 2.78, and 4.42 respectively. In our study, only 4 specimens had single seta 1 on segments III and VI (2.5%) and the remaining beard double seta (97.5%). The maximum 3-6 branches seta 1a-S and 1b-S (95%) were observed on siphon.

CONCLUSION

More populations of Culex pipiens from different areas of Iran need to be studied to gain complete information about the taxonomy and ecology of the species in the country.