Meta-analysis Study of Work-related Musculoskeletal Disorders in Iran

Objective Work-related musculoskeletal disorders are one of the major causes of lost working time, increased costs, human injuries and burnout. The International Labor Organization estimates that about 160 million work-related illnesses occur worldwide each year, where the highest prevalent illnesses are musculoskeletal disorders. Several studies have been conducted In Iran to investigate the prevalence of these disorders, each providing different statistics. Therefore, considering the importance of these disorders, it is necessary to obtain accurate results with high statistical power and validate them. The aim of this study was to investigate the prevalence of work-related musculoskeletal disorders in Iran in order to obtain more accurate results by conducting a meta-analysis. Materials & Methods For this meta-analysis, searching was conducted in SID, MagIran, Iran-Medex, Google Scholar, Scopus, Web of Science, and PubMed databases using the keyword "work-related musculoskeletal disorders" in both Persian and English on studies conducted during 2001-2016 in various cities of Iran. Inclusion criteria were: investigating the prevalence of musculoskeletal disorders in a period of one year, being a cross-sectional or descriptive-analytical study, publication in Persian or English, availability of full-texts, assessment using standard methods (e.g. Nordic Musculoskeletal Questionnaire) and considering the prevalence of musculoskeletal disorders throughout the body (upper and lower extremities). The heterogeneity of the articles was evaluated using the I-2 statistics and the data were analyzed in STATA software using meta-analysis and random-effects model. Results In this study, 45 papers on work-related musculoskeletal disorders were studied. The overall sample size of these studies was 9813, with a mean number of 218 for each study. Most of studies were descriptive-analytical and cross-sectional. In all of them, the prevalence of musculoskeletal disorders in different parts of the body had been investigated. According to their results, the most prevalent workrelated musculoskeletal disorder in lower extremity was low back pain (0.49%) and in upper extremity, it was neck pain (39.3%). The prevalence of musculoskeletal disorders in other parts of the body were 39.32% in the neck, 36.9% in shoulders, 36.8% in the back, 34% in the wrist, 26.9% in legs, 20.5% in thighs and hips, and 16.2% in elbows. Conclusion There is a relatively high prevalence of musculoskeletal disorders in lower extremity (lower back) and upper extremity (neck and shoulders) of workers in Iran which is more acute compared to other countries, and need further studies to determine its causes. Therefore, more attention should be paid to the of the health of employees, and ergonomic intervention programs should be designed by managers and officials of organizations to prevent musculoskeletal disorders at workplaces. Since the workers in Iran are young, there may not be high musculoskeletal complaints at the present time, but in the future it will create some problems for them. Therefore, reducing working hours, changing workplace design such that the design of ordered chairs tables be in accordance with ergonomics principles and body dimensions, scheduling time for employees to exercise, and providing training courses for them to maintain proper physical condition at work are suggested as strategies to reduce the risk of musculoskeletal disorders.