Acoustical role of ear canal in exposure to the typical occupational noise levels.

Background: Exposure to noise associated with injuries has become a public health issue in recent years. This study aimed to show the role of the acoustical structure of the ear canal on the typical occupational sound pressure levels at different frequencies. Methods: This cross-sectional study was done on 20-30-year-old participants. White noise was used at 3 levels, including 75, 85, and 95 dB as the stimulus sound pressure levels (SSPLs). The speakers had a 1.5-meter distance from the participants and at the height of 87 centimeters from the lab ground and were located in front of the participants. The SSPLs were measured outside (cavum part of the external ear) and inside the right ear of each participant. Measurements were done at the total sound pressure level and in the 1/1 octave frequencies. The duration for each measurement was 10 seconds. The independent sample t test was used for the statistical analysis, and the equality of means were rejected at p<0.05. Results: There were 30 (50%) males out of the 60 participants. The mean ± SD for the age of all the participants was 23.29±2.93 years. The total sound pressure level difference between the inside and outside of the ears of male and female participants was statistically significant (p<0.001) at the stimulus sound pressure levels. The peak resonance was observed in the frequencies 2000 Hz and 8000 Hz for males and 8000 Hz for females. Conclusion: The ear canal can amplify the sounds and increase the sound pressure levels. This amplification was found to be greater for males than for females.

Prevalence of high blood pressure in Iranian adults based on the 2017 ACC/AHA guideline.

Background: : In 2017, American College of Cardiology (ACC) and the American Heart Association (AHA) presented a new guideline for assessing blood pressure in adults. This study aimed to assess the prevalence of hypertension in Iranian adults based on ACC/AHA 2017 guideline. Methods: Data from 9801 Iranian adults (59.2% women) aged between 20-69 years were obtained from the sixth round of National Surveillance of Risk Factors of Non-Communicable Diseases (SuRFNCD) performed in 2011. Blood pressure was classified as normal, elevated blood pressure, and stage 1 and 2 hypertension using a weighted analysis and 2017 ACC/AHA guidelines. Data were presented as prevalence and 95% confidence interval (95% CI). All analyses were performed in Stata/SE 14.0. Results: Overall prevalence of hypertension in Iranian men was 52.0%. Also, 32.9% (95% CI: 29.9-36.0) and 19.1% (95% CI: 16.9-21.6) of men had stage 1 and 2 hypertension, respectively. In addition, 44.3% of women had hypertension, of whom 26.3% (95% CI: 24.5 - 28.2) had stage 1 and 18.0% (95% CI: 16.1-20.1) stage 2 hypertension. Furthermore, 16.5% (95% CI: 14.4-18.9) and 9.6% (95% CI: 7.86-11.7) of men and women had elevated blood pressure, respectively. Conclusion: The findings of this study indicated that adopting the 2017 ACC/AHA guidelines showed a higher prevalence of adult hypertension (48.2%) in Iran. In this study, the prevalence of hypertension in men was higher than in women, which was steadily increased by age in older adults in both sexes.

The value of (18) F-fluorodeoxyglucose positron emission tomography for prediction of treatment response in gastrointestinal stromal tumors: a systematic review and meta-analysis.

BACKGROUND: Early detection of response to treatment is critically important in gastrointestinal stromal tumors (GIST). Therefore, the present systematic review and meta-analysis assessed the value of (18) f-fluorodeoxyglucose positron emission tomography ((18) FDG-PET) on prediction of therapeutic response of GIST patients to systemic treatments. METHODS: The literature search was conducted using PubMed, SCOPUS, Cochrane, and Google Scholar databases, and review article references. Eligible articles were defined as studies included confirmed GIST patients who underwent (18) FDG-PET as well as assessing the screening role of it. RESULTS: Finally, 21 relevant articles were included. The analysis showed the pooled sensitivity and specificity of 18FDG-PET in evaluation of response to treatment of GIST patient were 0.90 (95% CI: 0.85-0.94; I(2) = 52.59, P = 0.001) and 0.62 (95% CI: 0.49-0.75; I(2) = 69.7, P = 0.001), respectively. In addition, the pooled prognostic odds ratio of (18) FDG-PET for was 14.99 (95% CI, 6.42-34.99; I(2) = 100.0, P < 0.001). The Meta regression showed that sensitivity of (18) FDG-PET was higher if the sample size of study was equal or more than 30 cases (sensitivity = 0.93; 95% CI: 0.89-0.97), when using PET/CT (sensitivity = 0.92; 95% CI: 0.89-0.97), and self-design criteria (sensitivity = 0.93; 95% CI: 0.87-1.0). CONCLUSION: The present meta-analysis showed (18) FDG-PET has a significant value in predicting treatment response in GIST patients.

Risk Factors of Work-Related Head and Neck Injuries: A National Survey.

Background: Occupational accidents made injuries in different parts of the body; two important parts of them are head and neck. We aimed to identify the risk factors of work-related head and neck injuries with using of a nationwide occupational accident data. Methods: This analytical cross-sectional study was conducted on the nationwide data that was gathered in 2013-2018. The target population was industrialized and non-industrialized adults, aged 18 yr or older. Dependent variable was the head and neck injuries. The independent variables were included, age, sex, education level, work experience, job, shift work, injury cause, referred center, season, accident day, accident time, and action after accident. Univariate logistic regression analyses and subsequently, a multivariate logistic regression model was used for analysis. Results: Out of the 17066 injured workers, 4072 (23.86%) subjects had head and neck injuries. The results of multivariate logistic regressions model showed, age ranges 30-39 (OR = 1.218; 95% CI: 1.036,1.433; P= 0.017), 40-49 (OR = 1.313; 95% CI: 1.044,1.652; P= 0.020), and >= 60 (OR=1.620; 95%CI: 1.028,2.553; P=0.038) and having male sex (OR = 1.657; 95% CI: 1.075,2.555; P= 0.022) were final work-related risk factors of head and neck injuries in Iran. Also winter season (OR = 1.212; 95% CI: 1.00,1.469; P= 0.050) could increase the head and neck injuries odds. Conclusion: Older workers in Iran are more vulnerable against the occupational head and neck injuries. Moreover, having male sex was other risk factor of the head and neck injuries.

The Efficiency of Hearing Protective Devices against Occupational Low Frequency Noise in Comparison to the New Subjective Suggested Method.

Backround: Noise is one of the most important occupational and environmental health hazards. Exposure to loud noise can cause irrevocable hearing damage and loss of hearing. The aim of this study was to determine the efficiency of two samples of earmuff and earplug in low frequency noise reduction in comparison to subjective method. Methods: All the procedures of the work were done using the simulated human ear canal and the required microphone in the eardrum. At the octave frequencies, that is 31.5 and 63.5, 125, 250, 500, 1000, 2000, 4000, and 8000 Hz, and intensities of 85-90 dB, one stage was done by using the individual's subjective response relative to the received sound before and after using the ear protector. Results: The sound levels before and after the protection were significantly different in both the model and humans (P < 0.05). However, at 315 Hz frequency, the rate of attenuation is increased by 4 dB after placing the earplug and 14 dB after placing the earmuff, showing a reduction of 18 dB. Conclusions: This study verifies the increasing protection by simultaneous application of earplugs and earmuffs. Because of the laboratory evaluation of ear protectors, it is possible not to justify the proficiency of ear protectors in a subjective method.

Risk factors of fatal occupational accidents in Iran.

BACKGROUND: Occupational accidents are of most important consequences of globalization in developing countries. Therefore, investigating the causes of occupational accidents for improving the job situation and making operational policy is necessary. So the aim of this study was to investigate factors affecting the fatal occupational accidents and also calculate the years of life lost for dead workers. METHODS: This cross-sectional study was conducted on data related to the 6052 injured workers that was registered in the 2013 registry system of the Ministry of Health and Medical Education of Iran. Variables including sex, education, age, job tenure, injury cause, referred location of injured workers, occupation, shift work, season, accident day, damaged part of the body were chosen as independent variables. The Chi-squared and Fisher exact tests were used for univariate analysis and then exact multiple logistic regression was carried out to identify independent risk factors of fatal occupational accidents. Finally, for dead workers, years of life lost, according to the injury causes was calculated. RESULTS: Among the 6052 accidents reported, 33 deaths were recorded. Chi-square and Fisher exact tests showed that factors including: current job tenure (p = 0.01), damaged parts of the body (p < 0.001) and injury cause (p < 0.001) are associated with the fatal accidents. Also exact multiple logistic regression analysis showed a significant association between electric shocks as a cause of injury (OR = 7.04; 95% CI: 1.01-43.74; p = 0.02) and current job tenure more than 1 year (OR = 0.21; 95% CI: 0.05-0.70; p = 0.005) with the fatal accidents. The total amount of years of life lost based on causes of injuries was estimated 1289.12 years. CONCLUSIONS: In Iran, fatal accident odds in workers with job tenure more than 1 year was less in comparing to the workers with job tenure less and equal to 1 year. Also odd of death for electrical shock was more than other causes of injuries. So it seems that employing of workers who have more than one-year work experience in a specific job and using of appropriate safeguards will be useful for the reducing of fatal occupational accidents.

The Gap of Cigarette and Hookah Smoking Between Socioeconomic Groups in Iran: Effect of Inequalities on Socioeconomic Position.

BACKGROUND: Hookah and cigarette smoking have adverse effects on individuals' health and therefore place a great burden on public health. The aim of this study was to measure inequalities in socioeconomic position to determine contributing factors on cigarette and hookah smoking in Iran. METHODS: In this study, secondary analysis of the Iran's sixth national Surveillance of Risk Factors of Non-Communicable Diseases (SuRFNCD-2011) was conducted for 10,572 individuals aged 15 to 70 years old. Subjects were categorized into three groups according to their socioeconomic status (low, middle and high) in order to assess their inequalities using principal component analysis. At the end, the gap between the low and high socioeconomic groups was decomposed using Blinder-Oaxaca decomposition technique. RESULTS: The prevalence of cigarette and hookah smoking in high, middle, and low socioeconomic groups was 11.8%, 13.2%, and 13.1% (P=0.158), and 2.6%, 3.3% and 4.3%, (P<0.001), respectively. Blinder-Oaxaca decomposition technique showed a lower prevalence of hookah smoking in high socioeconomic group compared to low socioeconomic group (P<0.001). The gap between the two mentioned groups was measured to be 1.7%. However, this gap for cigarette smoking (1.5%) was not significant (P=0.093). CONCLUSION: The finding indicates the importance of socioeconomic status in hookah smoking. After decomposition of the gap between the 2 socioeconomic groups, age, gender and education level were reported to be the major contributors to the differences observed between the 2 groups.

Screening Performance Characteristic of Ultrasonography and Radiography in Detection of Pleural Effusion; a Meta-Analysis.

INTRODUCTION: The role of ultrasonography in detection of pleural effusion has long been a subject of interest but controversial results have been reported. Accordingly, this study aims to conduct a systematic review of the available literature on diagnostic value of ultrasonography and radiography in detection of pleural effusion through a meta-analytic approach. METHODS: An extended search was done in databases of Medline, EMBASE, ISI Web of Knowledge, Scopus, Cochrane Library, and ProQuest. Two reviewers independently extracted the data and assessed the quality of the articles. Meta-analysis was performed using a mixed-effects binary regression model. Finally, subgroup analysis was carried out in order to find the sources of heterogeneity between the included studies. RESULTS: 12 studies were included in this meta-analysis (1554 subjects, 58.6% male). Pooled sensitivity of ultrasonography in detection of pleural effusion was 0.94 (95% CI: 0.88-0.97; I2= 84.23, p<0.001) and its pooled specificity was calculated to be 0.98 (95% CI: 0.92-1.0; I2= 88.65, p<0.001), while sensitivity and specificity of chest radiography were 0.51 (95% CI: 0.33-0.68; I2= 91.76, p<0.001) and 0.91 (95% CI: 0.68-0.98; I2= 92.86, p<0.001), respectively. Sensitivity of ultrasonography was found to be higher when the procedure was carried out by an intensivist or a radiologist using 5-10 MHz transducers. CONCLUSION: Chest ultrasonography, as a screening tool, has a higher diagnostic accuracy in identification of plural effusion compared to radiography. The sensitivity of this imaging modality was found to be higher when performed by a radiologist or an intensivist and using 5-10MHz probes.

Application of Ultrasonography and Radiography in Detection of Hemothorax; a Systematic Review and Meta-Analysis.

INTRODUCTION: Hemothorax is one of the most prevalent injuries caused by thoracic traumas. Early detection and treatment of this injury is of utmost importance in prognosis of the patient, but there are still controversial debates on the diagnostic value of imaging techniques in detection of hemothorax. Therefore, the present study aimed to evaluate the diagnostic value of chest ultrasonography and radiography in detection of hemothorax through a systematic review and meta-analysis. METHODS: Two independent reviewers performed an extended systematic search in databases of Medline, EMBASE, ISI Web of Knowledge, Scopus, Cochrane Library, and ProQuest. Data were extract and quality of the relevant studies were assessed. The number of true positive, false positive, true negative and false negative cases were extracted and screening performance characteristics of two imaging techniques were calculated using a mixed-effects binary regression model. RESULTS: Data from 12 studies were extracted and included in the meta-analysis (7361 patients, 77.1% male). Pooled sensitivity and specificity of ultrasonography in detection of hemothorax were 0.67 (95% CI: 0.41-0.86; I2= 68.38, p<0.001) and 0.99 (95% CI: 0.95-1.0; I2= 88.16, p<0.001), respectively. These measures for radiography were 0.54 (95% CI: 0.33-0.75; I2= 92.85, p<0.001) and 0.99 (95% CI: 0.94-1.0; I2= 99.22, p<0.001), respectively. Subgroup analysis found operator of the ultrasonography device, frequency of the transducer and sample size to be important sources of heterogeneity of included studies. CONCLUSION: The results of this study showed that although the sensitivity of ultrasonography in detection of hemothorax is relatively higher than radiography, but it is still at a moderate level (0.67%). The specificity of both imaging modalities were found to be at an excellent level in this regard. The screening characteristics of ultrasonography was found to be influenced of the operator and frequency of transducer.

Comparison of Ultrasonography and Radiography in Detection of Thoracic Bone Fractures; a Systematic Review and Meta-Analysis.

INTRODUCTION: The potential benefit of ultrasonography for detection of thoracic bone fractures has been proven in various surveys but no comprehensive conclusion has been drawn yet; therefore, the present study aimed to conduct a thorough meta-analytic systematic review on this subject. METHODS: Two reviewers independently carried out a comprehensive systematic search in Medline, EMBASE, ISI Web of Knowledge, Scopus, Cochrane Library, and ProQuest databases. Data were summarized as true positive, false positive, true negative and false negative and were analyzed via STATA 11.0 software using a mixed-effects binary regression model. Sources of heterogeneity were further assessed through subgroup analysis. RESULTS: Data on 1667 patients (807 subjects with and 860 cases without thoracic fractures), whose age ranged from 0 to 92 years, were extracted from 17 surveys. Pooled sensitivity and specificity of ultrasonography in detection of thoracic bone fractures were 0.97 (95% CI: 0.90-0.99; I2= 88.88, p<0.001) and 0.94 (95% CI: 0.86-0.97; I2= 71.97, p<0.001), respectively. The same measures for chest radiography were found to be 0.77 (95% CI: 0.56-0.90; I2= 97.76, p<0.001) and 1.0 (95% CI: 0.91-1.00; I2= 97.24, p<0.001), respectively. The sensitivity of ultrasonography was higher in detection of rib fractures, compared to fractures of sternum or clavicle (97% vs. 91%). Moreover, the sensitivity was found to be higher when the procedure was carried out by a radiologist in comparison to an emergency medicine specialist (96% vs. 90%). CONCLUSION: Base on the findings of the present meta-analysis, screening performance characteristic of ultrasonography in detection of thoracic bone fractures was found to be higher than radiography. However, these characteristics were more prominent in detection of rib fractures and in cases where was performed by a radiologist.

The Most Important Causes of Death in Iranian Population; a Retrospective Cohort Study.

INTRODUCTION: Health care providers and health policy managers need updated and valid information regarding causes of death (COD) for development the health care facilities, directing primary prevention, assigning funds, and promoting public health. The major causes of death and its burden have not been yet appropriately identified in Iran. Although several studies had been carried out in this area, most of them were local or performed in the past years and need to be update. Thus, the present study aimed to address the major causes of death and its burden in Iran. METHODS: The present cross-sectional study was performed on graduate students and their families from February to March 2014. Through a two-stage random sampling procedure, data on 11315 subjects were obtained. The corresponding age of death, gender, and calendar year of death were inquired. All causes of death were categorized in nine groups including major cardiovascular disease, cancers, motor vehicle accidents, unintentional injuries, intentional injuries, stroke, lower respiratory infections, diabetes, and other reasons. Years of life lost (YLL) and person years of life lost were computed as the burden of diseases. RESULTS: Totally, 11315 (50.4% male) subjects were studied. The results regarding death of relatives revealed that 360 deaths occurred (66.9% male). COD in 95 cases (26.4%) was cardiovascular diseases, 64 (17.8%) motor vehicle accidents, 41 (11.4%) cancers, 23 (6.4%) unintentional injuries, 22 (6.1%) intentional injuries, 10 (2.8%) stroke, 8 (2.2%) lower respiratory infections, 6 (1.8%) diabetes, and 91 (25.3%) other reasons. The average YLL due to all COD was 34.4±18.5. YLL for motor vehicle accidents and injuries (unintentional and intentional) were higher than cardiovascular diseases (p<0.001). In addition, person years of life lost for motor vehicle accidents were 2613.1 years. Cardiovascular diseases (2159.4 years), cancers (1321.0 years), and unintentional injuries (990.4 years) were in the next ranks. CONCLUSION: Based on the findings, it seems that cardiovascular diseases, motor vehicle accidents, cancers, intentional and unintentional injuries are the major causes of death in Iranian population. Most of years of life lost were due to motor vehicle accidents, cardiovascular diseases and cancers, intentional and unintentional injuries, respectively.

Smoking and Physical Activity in Healthy Adults: A Cross-Sectional Study in Tehran.

BACKGROUND: Smoking and physical inactivity are two major risk factors for non-communicable diseases (NCDs). Not only these factors have a causal effect on NCDs, but they can also affect each other. This study aimed to assess the relationship between these factors as well as their effect on NCDs. MATERIALS AND METHODS: A total of 2,602 healthy adults aged 30-60 years participated in this survey in 2010. Data on demographic characteristics, medical history, smoking status, physical activity and anthropometric measures including weight and height were collected and analyzed. The effect of smoking on physical activity was evaluated by logistic regression adjusting for potential confounders. RESULTS: Among demographic characteristics, only age (P<0.001) and educational level (P<0.001) had a significant association with smoking status. Compared with nonsmokers, smokers had an odds ratio of 4.88 (95% CI, 3.34-7.13) for having unsatisfactory physical activity. CONCLUSION: The present study showed that cigarette smoking negatively affects the quality of physical activity.

Blood pressure percentiles by age and body mass index for adults.

Since no comprehensive study has been conducted on blood pressure (BP) percentiles established upon nationally representative sample population of adults, the present study aimed to construct the blood pressure percentiles by age, sex and body mass index (BMI) of the subjects. Analyses were based on data collected in 2011 from 8,425 adults aged 25 to 69 years old. Data on demographic characteristics, anthropometric measurements, and blood pressure was recorded for each subject. Linear Regression analysis was used to assess the adjusted relationship of age-sex-specific standard deviation scores of BMI, height, and weight with blood pressure. Four separate models for systolic blood pressure (SBP) and diastolic blood pressure (DBP) of men and women were constructed for BP percentiles according to age and BMI. Blood pressure increased with the rise in BMI and weight, but showed a negative correlation with height. SBP and DBP rose steadily with increasing age, but the rise in SBP was greater than DBP. Overweight and obese population, seem to fall into the category of hypertensive. The findings of present study show that BP percentiles are steadily increased by age and BMI. In addition, most obese or overweight adults are hypertensive.

Diagnostic Accuracy of Ultrasonography and Radiography in Detection of Pulmonary Contusion; a Systematic Review and Meta-Analysis.

INTRODUCTION: Ultrasonography is currently being used as one of the diagnostic modalities in various medical emergencies for screening of trauma patients. The diagnostic value of this modality in detection of traumatic chest injuries has been evaluated by several studies but its diagnostic accuracy in diagnosis of pulmonary contusion is a matter of discussion. Therefore, the present study aimed to determine the diagnostic accuracy of ultrasonography and radiography in detection of pulmonary contusion through a systematic review and meta-analysis. METHODS: An extended systematic search was performed by two reviewers in databases of Medline, EMBASE, ISI Web of Knowledge, Scopus, Cochrane Library, and ProQuest. They extracted the data and assessed the quality of the studies. After summarization of data into true positive, false positive, true negative, and false negative meta-analysis was carried out via a mixed-effects binary regression model. Further subgroup analysis was performed due to a significant heterogeneity between the studies. RESULTS: 12 studies were included in this meta-analysis (1681 chest trauma patients, 76% male). Pooled sensitivity of ultrasonography in detection of pulmonary contusion was 0.92 (95% CI: 0.81-0.96; I2= 95.81, p<0.001) and its pooled specificity was calculated to be 0.89 (95% CI: 0.85-0.93; I2 = 67.29, p<0.001) while these figures for chest radiography were 0.44 (95% CI: 0.32-0.58; I2= 87.52, p<0.001) and 0.98 (95% CI: 0.88-1.0; I2= 95.22, p<0.001), respectively. Subgroup analysis showed that the sources of heterogeneity between the studies were sampling method, operator, frequency of the transducer, and sample size. CONCLUSION: Ultrasonography was found to be a better screening tool in detection of pulmonary contusion. Moreover, an ultrasonography performed by a radiologist / intensivist with 1-5MHz probe has a higher diagnostic value in identifying pulmonary contusions.

Diagnostic Accuracy of Chest Ultrasonography versus Chest Radiography for Identification of Pneumothorax: A Systematic Review and Meta-Analysis.

BACKGROUND: Early detection of pneumothorax is critically important. Several studies have shown that chest ultrasonography (CUS) is a highly sensitive and specific tool. The present systematic review and meta-analysis was designed to evaluate the diagnostic accuracy of CUS and chest radiography (CXR) for detection of pneumothorax. MATERIALS AND METHODS: The literature search was conducted using PubMed, EMBASE, Cochrane, CINAHL, SUMSearch, Trip databases, and review article references. Eligible articles were defined as diagnostic studies on patients suspected for pneumothorax who underwent chest computed tomography (CT) scan and those assessing the screening role of CUS and CXR. RESULTS: The analysis showed the pooled sensitivity and specificity of CUS were 0.87 (95% CI: 0.81-0.92; I2= 88.89, P<0.001) and 0.99 (95% CI: 0.98-0.99; I2= 86.46, P<0.001), respectively. The pooled sensitivity and specificity of CXR were 0.46 (95% CI: 0.36-0.56; I2= 85.34, P<0.001) and 1.0 (95% CI: 0.99-1.0; I2= 79.67, P<0.001), respectively. The Meta regression showed that the sensitivity (0.88; 95% CI: 0.82 - 0.94) and specificity (0.99; 95% CI: 0.98 - 1.00) of ultrasound performed by the emergency physician was higher than by non-emergency physician. Non-trauma setting was associated with higher pooled sensitivity (0.90; 95% CI: 0.83 - 0.98) and lower specificity (0.97; 95% CI: 0.95 - 0.99). CONCLUSION: The present meta-analysis showed that the diagnostic accuracy of CUS was higher than supine CXR for detection of pneumothorax. It seems that CUS is superior to CXR in detection of pneumothorax, even after adjusting for possible sources of heterogeneity.