Developing decision model for the outsourcing of medical service delivery in the public hospitals.

BACKGROUND: The decision to outsource an activity is one of the most complex organizational decisions. This decision is also influenced by several factors and components. In order to facilitate and optimize it, for the first time in this study, a decision model for outsourcing medical service delivery in public hospitals has been developed. METHODS: We conducted this cross-sectional study in 3 stages: 1) We identified the factors affecting the outsourcing decisions, 2) an expert panel identified the influential factors. After standardization, we distributed 220 questionnaires among university staff managers and heads, nursing managers, and managers of the research units, and 3) Structural Equation Model applied to evaluate the relationship between the variables on AMOS22, at 0.05 significant level. RESULTS: Findings indicated the optimal level of all fit indices. The path coefficient between all identified factors with the outsourcing decision was positive (t > 1.96). Factors ranging from the most effective to least effective included monitoring and control, service type, human resource, economic and financial, executive capability, external environment, and terms and conditions. CONCLUSION: The proposed model provides unit evaluation to make the appropriate decision on outsourcing or non-outsourcing. Control and monitoring were the most determining factors. We recommend performing monitoring continuously as a guide and deterrent to error. We also recommend continuous monitoring and control over the quality of outsourced units and stakeholder satisfaction.

Working Memory Capacity and Relative Clause Attachment Preference of Persian EFL Learners: Does Segmentation Play Any Role?

To contribute to a better understanding of first language (L1) and second language (L2) sentence processing, this study investigated the relationship between working memory capacity (WMC) and relative clause (RC) attachment preference of Persian learners of English as a foreign language . Additionally, the impact of segmentation of experimental stimuli on the participants' RC attachment preferences was explored. The participants' L1 attachment preference was also measured as baseline. Sixty-two native speakers of Persian participated in offline reading tasks in return for course credit. Results of WM test revealed no correlation between the participants' WMC and both their L1 (Persian) and L2 (English) attachment preferences. Results of the impact of the segmentation of the stimuli, on the other hand, showed when L1 and L2 experimental sentences are displayed with a break between the second determiner phrase (DP2) and the RC, readers prefer to attach the RC more to the first determiner phrase (DP1), especially in L2 (English). This finding provides support for Fodor's (1998) Implicit Prosody Hypothesis. In addition, the study found a positive correlation between L1 and L2 attachment preferences. Also, in order to explore the possible interactions between the variables under investigation, linear mixed effects model was run. Results revealed no interaction between the variables of the study. These findings might justify both interlingual and to some extent intralingual variations in attachment preferences. The findings of the study provide some implications for language teachers with regard to raising L2 learners' awareness for the prosodic aspects of language and the role of L1 transfer in L2 sentence processing.

Metformin as a new option in the medical management of breast fibroadenoma; a randomized clinical trial.

BACKGROUND: Fibroadenoma (FA) is the most common benign solid breast mass in women, with no definite method of management. Because fibroadenoma is dependent on female sex hormones and comprises hypertrophic changes at cellular levels, we investigated the effects of metformin (MF), a safe hypoglycemic agent with anti-estrogenic and anti-proliferative properties, in the management of fibroadenoma. METHODS: In this randomized clinical trial study, eligible women with fibroadenomas were assigned randomly to the metformin (1000 mg daily for six months) or the placebo group. Breast physical and ultrasound exam was performed before and after the intervention, and the changes in the size of fibroadenomas were compared in the two groups. RESULTS: Overall, 83 patients in the treatment, and 92 in the placebo group completed the study. A statistically significant difference in changing size between the two groups was observed only in the smallest mass. In the largest FAs, the rate of size reduction was higher in the treatment group (60.2 % vs. 43.5 %); while a higher rate of enlargement was observed in the placebo group (38 % vs. 20.5 %). In the smallest FAs, the rate of the masses that got smaller or remained stable was about 90 % in the treatment group and 50 % in the placebo group. We categorized size changes of FAs into < 20 % enlargement and ≥ 20 % enlargement. The odds ratio (OR) for an elargemnt less than 20% was 1.48 (95 % CI = 1.10-1.99) in the treatment group in comparison with the placebo group; the odds for an enlargement less than 20% was higher in women with multiples fibroadenomas (OR = 4.67, 95 % CI: 1.34-16.28). In our study, no serious adverse effect was recorded, and the medicine was well-tolerated by all users. CONCLUSIONS: This is the first study that evaluates the effect of MF on the management of fibroadenoma, and the results suggest a favorable effect. Larger studies using higher doses of MF and including a separate design for patients with single or multiple FAs are suggested in order to confirm this effect. TRIAL REGISTRATION: This trial (IRCT20100706004329N7) was retrospectively registered on 2018-10-07.

Effectiveness of Integrating Simulation with Art-Based Teaching Strategies on Oncology Fellows' Performance Regarding Breaking Bad News.

The task of breaking bad news (BBN) may be improved by incorporating simulation with art-based teaching methods. The aim of the present study was to assess the effect of an integrating simulation with art-based teaching strategies, on fellows' performance regarding BBN, in Iran. The study was carried out using quasi-experimental methods, interrupted time series. The participants were selected from medical oncology fellows at two teaching hospitals of Tehran University of Medical Sciences (TUMS), Iran. Participants were trained through workshop, followed by engaging participants with different types of art-based teaching methods. In order to assess the effectiveness of the integrating model, fellows' performance was rated by two independent raters (standardized patients (SPs) and faculty members) using the BBN assessment checklist. This assessment tool measured seven different domains of BBN skill. Segmented regression was used to analyze the results of study. Performance of all oncology fellows (n = 19) was assessed for 228 time points during the study, by rating three time points before and three time points after the intervention by two raters. Based on SP ratings, fellows' performance scores in post-training showed significant level changes in three domains of BBN checklist (B = 1.126, F = 3.221, G = 2.241; p < 0.05). Similarly, the significant level change in fellows' score rated by faculty members in post-training was B = 1.091, F = 3.273, G = 1.724; p < 0.05. There was no significant change in trend of fellows' performance after the intervention. Our results showed that using an integrating simulation with art-based teaching strategies may help oncology fellows to improve their communication skills in different facets of BBN performance. Iranian Registry of Clinical Trials ID: IRCT2016011626039N1.

Zero-Inflated Count Regression Models in Solving Challenges Posed by Outlier-Prone Data; an Application to Length of Hospital Stay.

Introduction: Ignoring outliers in data may lead to misleading results. Length of stay (LOS) is often considered a count variable with a high frequency of outliers. This study exemplifies the potential of robust methodologies in enhancing the accuracy and reliability of analyses conducted on skewed and outlier-prone count data of LOS. Methods: The application of Zero-Inflated Poisson (ZIP) and robust Zero-Inflated Poisson (RZIP) models in solving challenges posed by outlier LOS data were evaluated. The ZIP model incorporates two components, tackling excess zeros with a zero-inflation component and modeling positive counts with a Poisson component. The RZIP model introduces the Robust Expectation-Solution (RES) algorithm to enhance parameter estimation and address the impact of outliers on the model's performance. Results: Data from 254 intensive care unit patients were analyzed (62.2% male). Patients aged 65 or older accounted for 58.3% of the sample. Notably, 38.6% of patients exhibited zero LOS. The overall mean LOS was 5.89 (± 9.81) days, and 9.45% of cases displayed outliers. Our analysis using the RZIP model revealed significant predictors of LOS, including age, underlying comorbidities (p<0.001), and insurance status (p=0.013). Model comparison demonstrated the RZIP model's superiority over ZIP, as evidenced by lower Akaike information criteria (AIC) and Bayesians information criteria (BIC) values. Conclusions: The application of the RZIP model allowed us to uncover meaningful insights into the factors influencing LOS, paving the way for more informed decision-making in hospital management.

Performance analysis of indicators in teaching hospitals after the Health Transformation Plan: a Case Study in Iran.

BACKGROUND: This study aimed to examine the status of performance indicators in hospitals affiliated with Qazvin University of Medical Sciences (QUMS) before and after the implementation of the Health Transformation Plan (HTP). METHODS: This longitudinal descriptive-analytical study was conducted utilizing hospital data. The study collected data using a checklist that included both general characteristics of the participating hospitals and performance indicators such as "the number of outpatient visits," "the number of paraclinical patients," "the number of surgeries," and "the number of inpatients" on a monthly basis for 2012-2019. The intervention examined in this study was the implementation of the HTP in May 2014. The data collected was analyzed using interrupted time series and STATA statistical software version 15. RESULTS: The study examined seven hospitals affiliated with QUMS, including general, trauma, pediatric, gynecology, and psychiatry hospitals. The findings indicated a significant increase in outpatient visits, paraclinical patients, and inpatients in the first month after the intervention. Specifically, there was an increase of 1739 in the number of outpatient visits, an increase of 513 in the number of paraclinical patients, and an increase of 135 in the number of inpatients (p < 0.001). CONCLUSION: The HTP has improved patients' access to medical services. It achieved this by reducing out-of-pocket payments for healthcare services and implementing programs such as developing clinics, improving the quality of visits, and retaining doctors in deprived areas. The reduction in out-of-pocket payments has been particularly beneficial for individuals who lack financial resources and previously faced barriers to accessing healthcare services.

Analysis of polychlorinated biphenyls (PCBs) in dairy products by modified QuEChERS/GC-QqQ-MS/MS method: A risk assessment study.

Polychlorinated biphenyls (PCBs) are harmful chemicals that are persistent in the environment and can accumulate in the food chain. The purpose of the present research was to assess non-dioxin-like polychlorinated biphenyls (NDL-PCBs) in some dairy products (yogurt, doogh, and kashk) using modified QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) technique and gas chromatography-triple-quadrupole mass spectrometry (GC-QqQ-MS/MS) method and risk assessment study. The LOQs (limit of quantifications), LODs (limit of detections), recovery, and RSD for the PCB analytes were 0.180-0.360, 0.06-0.12 ng/g fat, 97.45-102.63%, and 6.33-8.86%, respectively. The results revealed that the mean concentrations of Æ©6-NDL-PCBs in samples were 15.17 ± 3.44 ng/g fat, which was lower than the standard level established by European Union (EU, 40 ng/g fat). The maximum mean level was PCB 180 (9.98 ± 2.04 ng/g fat) and the minimum mean level of PCBs in samples was PCB 28 (0.09 ± 0.06 ng/g fat). Also, results showed that kashk samples had a maximum mean level of 6-NDL-PCBs (18.66 ± 2.42 ng/g fat) and doogh samples had a minimum mean level of 6-NDL-PCBs (12.21 ± 2.22 ng/g fat). The mean level of 6-NDL-PCBs in yogurt samples was 14.65 ± 2.02 ng/g fat. The heat map results showed the correlation between the spectral indices of 6-NDL-PCBs in different dairy products. According to the Monte Carlo method, risk assessment was done using calculating the Estimated Daily Intake (EDI) and Incremental Life Cancer Risk (ILCR). The EDI values of 6 NDL-PCBs based on the 95th percentile in yogurt, doogh, and kashk were 14.3, 1.49, and 0.5 ng/kg.day, respectively. Considering that the contaminant level in the samples is lower than the EU limit, it can be concluded that dietary exposure to 6 NDL-PCBs may not pose a risk to the health of consumers.

Amphotericin B-Loaded Extracellular Vesicles Derived from Leishmania major Enhancing Cutaneous Leishmaniasis Treatment through In Vitro and In Vivo Studies.

Background: Recent studies have shown an increasing number of patients with cutaneous leishmaniasis (CL) who do not respond to pentavalent antimonials as the first line of treatment for CL. Nanocarriers such as extracellular vesicles (EVs) are efficient vehicles that might be used as drug delivery systems for the treatment of diseases. Therefore, we aimed to isolate and characterize the EVs of Leishmania major, load them with Amphotericin B (AmB), and investigate the toxicity and efficacy of the prepared drug form. Methods: The EVs of L. major were isolated, characterized, and loaded with amphotericin B (AmB), and the EVs-Amphotericin B (EVs-AmB) form was synthesized. Relevant in vitro and in vivo methods were performed to evaluate the toxicity and efficacy of EVs-AmB compared to the control. Results: The anti-leishmanial activity of the EVs-AmB showed a higher percentage inhibition (PI%) (P = 0.023) compared to the AmB at different concentrations and time points. Obtained data showed a significant increase in the lesion size and parasite load in the lesion, PBS, and EVs mice groups in comparison with EVs-AmB, AmB, and Glucantime groups (P < 0.05), EVs-AmB had a significant decrease in lesion sizes in comparison with AmB (P < 0.05). Results showed that EVs-AmB decreased its toxicity to the kidneys and liver (P < 0.05). Conclusion: EVs-AmB improved the efficacy of AmB in mouse skin lesions and reduced hepatorenal toxicity. Furthermore, EVs could be a promising nanoplatform for the delivery of AmB in CL caused by L. major.

Nutritional knowledge, attitude, and practice of professional athletes in an Iranian population (a cross-sectional study).

BACKGROUND: Proper nutrition is vital in promoting community health, yet insufficient knowledge and improper dietary practices can lead to deficiencies and diseases. Professional athletes depend on optimal nutrition for their performance and recovery, but a lack of understanding can impede their potential. The nutritional status of athletes impacts their overall health and sports performance. Inadequate sports nutrition knowledge may result in suboptimal practices, reducing strength, power, endurance, and immunity. Additionally, disordered attitudes can lead to dietary imbalances and an increased risk of injury. This study, conducted in Qazvin, Iran, examined athletes' nutritional knowledge, attitudes, and practices. By addressing these factors, there is potential to enhance dietary behaviors and ultimately improve athletes' performance. METHODS: The study employed a descriptive-analytical, cross-sectional design to investigate the nutritional knowledge, attitude, and practice (KAP) of professional athletes in Qazvin, Iran. A total of 320 purposefully selected professional athletes (68.13% male, 31.87% female) from various sports fields participated in the research. The data collection tool consisted of demographic questions and a KAP questionnaire, including 27 nutritional knowledge questions, 16 nutritional attitude questions, and 14 nutritional performance questions. The quota sampling method was used to estimate sample sizes. Data analysis was carried out by SPSS v.26 using one sample t-test, one-way ANOVA, and Pearson's correlation coefficient test. RESULTS: The results showed that nutritional knowledge (the mean value was 79.594 ± 7.015 - the optimal knowledge level = 84) and attitude (the mean value was 23.347 ± 5.300 - the optimal attitude level = 26) for athletes are low, but their nutritional practice (the mean value was 21.788 ± 3.450 - the optimal performance level = 24) was moderate. Also, professional athletes' nutritional knowledge, attitude, and practice were lower than normal (p < 0.05). Significant positive correlations were among knowledge, attitude, and practice (p < 0.05). However, there were no significant differences in nutritional knowledge, attitude, and practice among the subjects of different age groups, genders, and sports types (p > 0.05). CONCLUSION: This study showed that the nutritional knowledge, attitude, and practice of professional Iranian athletes in Qazvin province were low; therefore, the implementation of more theoretical and applied nutrition education, such as using knowledge assessment tools and interventions, irrespective of their age, sport's field, and gender, is compelling.

Simultaneous and selective electrochemical sensing of methotrexate and folic acid in biological fluids and pharmaceutical samples using Fe3O4/ppy/Pd nanocomposite modified screen printed graphite electrode.

The purpose of this study was to fabricate an electrochemical sensor for the detection of methotrexate and folic acid based on a screen-printed graphite electrode (SPGE) modified with prepared iron oxide (Fe3O4)/polypyrrole (ppy)/Palladium (Pd) nanocomposite. Transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FT-IR) techniques were employed to characterize the Fe3O4/ppy/Pd nanocomposite. The produced modifier was used to induce a remarkable electrocatalytic impact relative to the oxidation of methotrexate, which caused the potential peak shift to a less positive amount (from 800 mV to about 500 mV) and improved the peak current (from 5.3 µA to about 16 µA). Methotrexate peak current was linearly dependent on its concentration from 0.03100.0 µM and the limit of detection (LOD) was estimated at 7.0 nM. The methotrexate and folic acid were co-detected by the proposed sensor. The experimental results indicated that the oxidation peaks of methotrexate and folic acid were separated about 200 mV in phosphate buffer solution (PBS) at pH 7.0. Fe3O4/ppy/Pd/SPGE was successfully able to detect methotrexate and folic acid in pharmaceutical and biological samples with excellent recovery.

Probabilistic Health Risk Assessment of Trace Elements in Baby Food and Milk Powder Using ICP-OES Method.

This study was conducted to evaluate the concentration and health risk of trace elements in milk powder and baby food samples marketed in Iran using inductive couple plasma/optical emission spectroscopy (ICP-OES) method. The limit of detection (LOD) and limit of quantification (LOQ) were ranged from 1.80 × 10-5 to 2.17 × 10-3 and 6.00 × 10-5 to 7.22 × 10-3 mg/kg, respectively, with recoveries ranged from 92 to 105%. Zinc (Zn) was found in a high mean concentration (8.49 × 10-1 ± 3.93 × 10-2 mg/kg) in milk powder, and iron (Fe) was found in the highest mean concentration (2.04 ± 3.61 × 10-2 mg/kg) in baby food. The Monte Carlo simulation results for the infants revealed that the rank order of the hazard quotient (HQ) index was mercury (Hg) > nickel (Ni) > arsenic (As) > cadmium (Cd) > aluminum (Al). Further, the result of non-carcinogenic and probability of carcinogenic risk was lower than the limits of safe risk (HQ > 1 and cancer risk (CR) > 1 × 10-4). In conclusion, the toxic elements content in the tested products was sufficiently low, and all of the milk powder and baby food sold in Iran could be considered safe for infants and children.

Is Social Distancing Policy Effective in Controlling COVID-19? An Interrupted Time Series Analysis.

INTRODUCTION: The social distancing plan is one of the ways that was implemented for management of COVID-19 pandemic. This study aimed to evaluate the effect of the social distancing on reducing the daily new cases and deaths from COVID-19. METHODS: In this cross-sectional study, the data of daily new cases and daily deaths were collected from 15/02/2020 to 19/04/2020. Changes in the level and trend of daily new cases and daily deaths before and after the implementation of social distancing plan were evaluated using interrupted time series (ITS) analysis in STATA software. RESULTS: The post-intervention trend had a decrease of 102 new cases per day and 7 new deaths per day compared to the pre-intervention trend (p < 0.001). Moreover, in the post-intervention period, the daily new cases had a decrease of 58 new cases per day and 2 new deaths per day (p < 0.001). CONCLUSION: It Could be concluded that social distancing plan directly affects the new daily cases and new daily deaths.

Monitoring of polycyclic aromatic hydrocarbons and probabilistic health risk assessment in yogurt and butter in Iran.

This study was conducted to determine the polycyclic aromatic hydrocarbons (PAHs) levels and health risk of yogurt and butter samples collected from Tehran using MSPE/GC-MS (magnetic solid-phase extraction/gas chromatography-mass spectrometry). The results revealed that the limit of detection (LOD) and limit of quantification (LOQ) were ranged from 0.040 to 0.060 and 0.121 to 0.181 µg/kg, respectively; with recoveries ranged from 86.1% to 100.3%. The highest mean of total PAHs was higher in butter (6.87 ± 1.21 µg/kg) than in yogurt (3.82 ± 0.54 µg/kg). The level of benzo (a)pyrene in all samples was lower than of standard levels of the European Union (EU). The highest value of all PAHs in samples was recorded in the winter season and also in the expiration date. The percentile 95% of the total hazard quotient (THQ) due to the consumption of yogurt and butter recorded 1.33E-02 and 3.69E-04 in adults and 6.12E-02 and 1.75E-03 in children, respectively. The percentile of 95% incremental lifetime of cancer risk (ILCR) due to the ingestion of yogurt and butter recorded 1.17E-06 and 2.02E-08 for adults and 5.51E-06 and 9.46E-08 for children, respectively. The rank order of 7 PAHs in adult and children based on P95% Hazard Quotient (HQ) in all samples was benzo(a)anthracene (BaA) > pyrene (P) > fluorene (F) > fluoranthene (Fl) > acenaphthylene (Ace) > anthracene (A) > naphthalene (NA). According to the Monte Carlo Simulation (MCS) method, health-risk assessment showed that children and adults are not at significant health risk.

The relationship between posttraumatic growth and cognitive emotion regulation strategies in hemodialysis patients.

BACKGROUND AND AIM: Posttraumatic growth following traumas such as chronic illnesses can occur in some people. The psychological factors, such as cognitive emotion regulation (CER), can influence its formation. CER is a type of coping strategy that helps to efficiently deal with trauma. Due to the importance of the topic and the lack of sufficient studies on posttraumatic growth and CER in hemodialysis patients, this study aims to investigate the relationship between posttraumatic growth and CER in hemodialysis patients. METHODS: This is a descriptive study performed on hemodialysis patients in Bou Ali and Velayat hospitals in Qazvin. One hundred and sixty-two patients were selected by the convenience sampling method, and Garnefski Cognitive Emotion Regulation Questionnaire (α =0.92) and Tedeschi Posttraumatic Growth Questionnaire (α =0.96) were used. Data were analyzed using Pearson correlation and ANOVA tests. RESULTS: The results showed that the majority of the hemodialysis patients experienced some degree of posttraumatic growth. The participants achieved high scores in the domains of spiritual development and communication with others. Moreover, posttraumatic growth was positively and significantly correlated with CER (r = 0.67, P < 0.001). CONCLUSIONS: Hemodialysis provides the basis for the positive mental reactions known as posttraumatic growth in hemodialysis patients. Nurses and other authorities can use this phenomenon to adapt to illness and care planning.

Predicting Inpatient Length of Stay in Iranian Hospital: Conceptualization and Validation.

OBJECTIVE: The length of stay is an important indicator of hospital performance and efficiency. Regarding the importance of the length of stay, this study aimed to design a structural model of the inpatients' length of stay in the educational and therapeutic health care facilities of Iran in order to identify the influencing dimensions. METHODS: The present study was an analytical and applied study. The face validity of the data gathering tool was investigated by the expert judgment and the construct validity was examined by using the exploratory factor analysis. In order to verify the reliability of the tool, the internal consistency was also trialed by using the Cronbach's alpha. For ranking the influencing dimensions and factors and also in order to examine the causal relationships between the variables in a coherent manner and presenting the final model, the structural equation modeling technique was used in AMOS software at a significant level of 0.05. RESULTS: The mentioned structural model consists of 4 dimensions and 29 factors influencing the length of stay of hospitalized patients. The independent variables are based on priority and importance as follows: patients' conditions, the underlying factors, the clinical staff performance, and hospitals' service delivery, which were examined by second-order factor analysis in order to study the relationship between them and the inpatients' length of stay. CONCLUSION: Considering the importance of each one of the proposed dimensions from the point of view of service providers in some therapeutic centers of the country by paying attention to the role of each one of them in preventing prolonged hospitalization can be essential in the effectiveness of the treatment and cost reduction.
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Interaction of Safety Climate and Safety Culture: A Model for Cancer Treatment Centers

Background: In health care institutions, safety culture is defined as the integrity of individual and group efforts to reduce the harms for the patients. This is possible through interactions, attitudes, and understanding of safety matters. On the other hand, one of the indicators of the safety culture is the safety climate. Objective: The aim of this study is to investigate the interaction between safety climate and safety culture using structural equation modeling in personnel of cancer treatment centers in Iran. Methods: In this study, 680 personnel of Iran's hospitals were chosen in a random manner. Demographic (9 questions), safety culture (42 questions) and safety climate (37 questions) questionnaires were filled. The data were inserted in SPSS 20 software. Descriptive statistics method and Pearson's correlation coefficient were used to describe the data and evaluate the relation between the variables, respectively. Structural equations model was developed using AMOS 22 software and fitness of the model was tested by χ2, RMSEA, GFI and NFI statistics. Results: The scores of safety climate and safety culture were 3.61 and 3.30, respectively, which imply that they are suiTable. The overall fitness of the model was accepTable. In this model, χ2 = 8637.17, df = 2964, χ2/df = 2.914, RMSEA = 0.058, NFI = 0.912, GFI=0.907, and CFI=0.875. In the regression analysis, there were positive significant relationships between safety climate and safety culture, safety climate and any of its components, and safety culture and any of the components. Conclusion: It was found that the safety climate and the safety culture had a positive impact on each other; so that with increasing safety climate, the safety culture also increases, and vice versa. Also, the level of education has a positive impact on safety culture and safety climate. So appropriate training can promote both variables in cancer treatment hospitals.

Effect of Occupational Exposure to Radar Radiation on Cancer Risk: A Systematic Review and Meta-Analysis.

OBJECTIVE: Microwave radiation is one of the most growing environmental workplace factors that exposes too many workers in the various workplaces. Regard to concerns about cancer incidence in these workers and lack of systematic or meta-analytic studies about this object, so, we conducted a meta-analysis to acquire an understanding of the association between cancer risk and occupational exposure to radar radiation. METHODS: A systematic search was carried out on case-control, cohort and clinical control trial studies that published in the Cochrane Library, PubMed, ISI Web of Science, Scopus and Google scholar databases that accomplished from March 2017 to March 2018 and updated on 30 September, 2018 in English and Persian articles without time limit in publication date. Keywords were selected based on PICO principle and collected from MeSH database. After removal of duplicated studied, taking into inclusion and exclusion criteria, the process of screening was carried out and data were extracted after preparation of the full text of included articles. Article collection was completed by manually searching for a reference list of eligible studies. For quality assessment of included studies, Newcastle-Ottawa scale was used. RESULTS: a total of 533 studies was found in the first step of literature search, only 6 were included with 53,008 sample size according to inclusion and exclusion criteria. Estimated pooled random effects size analysis showed no significant increasing effect of occupational exposure to radar radiation on mortality rate (MR=0.81, 95%CI: 0.78, 0.83) and relative risk (RR=0.87, 95%CI: 0.75, 0.99, P <0.0001) of cancer with a significant heterogeneity between the selected studies. CONCLUSIONS: In conclusion, the results of this meta-analysis study have shown no significant increase in overall mortality ratio and cancer risk ratio from occupational exposure to the radar frequency of workers. But, these results are not conclusive. As regards to some limitation such as fewer numbers of included studies, lack of data about exposure characterizations and demographic characterizations in this meta-analysis, this result is not certain and conclusive. It is recommended to conduct future studies.