Pattern of Use of Earphone and Music Player Devices among Iranian Adolescents.

BACKGROUND: There is no information about the pattern of use of earphones and music players in Iranian adolescents. The aim of this study was to assess the prevalence and pattern of the use of earphone and music player devices as a main risk factor for hearing loss in adolescents of Tabriz city, northwest of Iran. METHODS: In this cross-sectional study in November 2011, 2,359 high school students were randomly selected and were asked to complete a 20-item questionnaire about the pattern of using earphones and music players. RESULTS: The results showed that 44.3% [confidence interval (CI) 95%: 38.3-50.3] of the respondents had a history of hearing problems that was significantly different between males and females (42.2% of males and 47% of females, p: 0.02). Notably, 36.8% of the participants stated that they listened to music without any rest or stop. Almost 49.6% (CI 95%: 44.4-54.4) of the students reported listening to 'somewhat loud' (gain setting at 50%) or 'very loud' (gain setting more than 50%) volume level of music. In terms of the kind of earphones, 17.1% of the participants used headphones, 34.8% used earbud-style headphones, 32.3% used supra-aural headphones, and 15.8% of them did not use any type of earphones. CONCLUSIONS: Students have risky patterns of using earphones and music-listening devices. Planning educational programs in this domain for adolescents especially in high schools is necessary.

Assessing misdiagnosis of relapse in patients with gastric cancer in Iran cancer institute based on a hidden Markov multi-state model.

BACKGROUND: Accurate assessment of disease progression requires proper understanding of natural disease process which is often hidden and unobservable. For this purpose, disease status should be clearly detected. But in most diseases it is not possible to detect such status. This study, therefore, aims to present a model which both investigates the unobservable disease process and considers the error probability in diagnosis of disease states. MATERIALS AND METHODS: Data from 330 patients with gastric cancer undergoing surgery at the Iran Cancer Institute from 1995 to 1999 were analyzed. Moreover, to estimate and assess the effect of demographic, diagnostic and clinical factors as well as medical and post-surgical variables on transition rates and the probability of misdiagnosis of relapse, a hidden Markov multi-state model was employed. RESULTS: Classification errors of patients in alive state without a relapse (e21) and with a relapse (e12) were 0.22 (95% CI: 0.04-0.63) and 0.02 (95% CI: 0.00-0.09), respectively. Only variables of age and number of renewed treatments affected misdiagnosis of relapse. In addition, patient age and distant metastasis were among factors affecting the occurrence of relapse (state1→state2) while the number of renewed treatments and the type and extent of surgery had a significant effect on death hazard without relapse (state2→state3) and death hazard with relapse (state2→state3). CONCLUSIONS: A hidden Markov multi-state model provides the possibility of estimating classification error between different states of disease. Moreover, based on this model, factors affecting the probability of this error can be identified and researchers can be helped with understanding the mechanisms of classification error.

Inequality of leprosy disability in iran, clinical or socio-economic inequality: an extended concentration index decomposition approach.

BACKGROUND: Despite significant reduction in global disease prevalence, leprosy still has a high rate of disability while its determinants are unfair and many of them are amendable. The objective of this study was to measure inequality of disability in leprosy in Iran. METHODS: This was a cross-sectional study (2006-2007) on all living people affected by leprosy registered in W. Azerbaijan province health center, Western North of Iran. The outcome of the study was the socio-economic inequality considering presence or absence of grade 2 disability (G2D) based on the WHO classifications. An extended concentration index decomposition approach was used for analysis. RESULTS: Among 452 cases, 65.3% were male and 67% were affected by the multi bacillary type. Overall G2D was 65.3%. The estimated Concentration Index was -0.0782, showing presence of pro-poor socio-economic inequality of G2D, while extended CI estimation (ѵ = 5) was -0.163. Achievement index with coefficient (ѵ = 5) revealed that G2D mean was 16% more than classic mean in the poorest group. The result of decomposition of the existing inequality revealed that, some of the determinants such as receiving mono-therapy, education, urbanization, and bacillus calmette guerin (BCG) vaccination had shared contribution (67.4%, 61.8%, 59.2%, and 57.5% respectively). CONCLUSIONS: This study provided new perspective for the health system to leprosy control considering the significant gap between rich and poor (inequality) regarding G2D disability, and its effective elements in socio-economic strata. Some effective actions can be considered to reduce the scale of existing inequality.

Comparison between parametric and semi-parametric cox models in modeling transition rates of a multi-state model: application in patients with gastric cancer undergoing surgery at the Iran cancer institute.

BACKGROUND: Research on cancers with a high rate of mortality such as those occurring in the stomach requires using models which can provide a closer examination of disease processes and provide researchers with more accurate data. Various models have been designed based on this issue and the present study aimed at evaluating such models. MATERIALS AND METHODS: Data from 330 patients with gastric cancer undergoing surgery at Iran Cancer Institute from 1995 to 1999 were analyzed. Cox-Snell Residuals and Akaike Information Criterion were used to compare parametric and semi-parametric Cox models in modeling transition rates among different states of a multi-state model. R 2.15.1 software was used for all data analyses. RESULTS: Analysis of Cox-Snell Residuals and Akaike Information Criterion for all probable transitions among different states revealed that parametric models represented a better fitness. Log-logistic, Gompertz and Log-normal models were good choices for modeling transition rate for relapse hazard (state 1?state 2), death hazard without a relapse (state 1?state 3) and death hazard with a relapse (state 2?state 3), respectively. CONCLUSIONS: Although the semi-parametric Cox model is often used by most cancer researchers in modeling transition rates of multi- state models, parametric models in similar situations- as they do not need proportional hazards assumption and consider a specific statistical distribution for time to occurrence of next state in case this assumption is not made - are more credible alternatives.

Residential segregation of socioeconomic variables and health indices in iran.

BACKGROUND: Measures of segregation are essential tools for evaluation of social equality. They describe complex structural patterns by single quantities and allow the comparison of inequalities over time or between residential places. In many countries, patterns of residential segregation are well described (e.g., South Africa, Great Britain, United States of America). In this study, for the first time in Iran, we measured residential segregation for some socioeconomic and health variables and described their pair wise correlation. METHODS: We measured evenness dimension of segregation by generalized dissimilarity segregation index and information theory index and its ordinal equivalent for some determinants of socioeconomic status and health variables using data of last national census in Iran. Segregation indices were computed for 31 socioeconomic variables and four health indices. RESULTS: All the provinces were in the category of low segregation for individual and family disability and death of at least one offspring of mother, but for infant mortality half of the provinces were moderately or highly segregated. For some of socioeconomic variables, many provinces were in the category of moderate, high, or extreme segregation. There was significant correlation between segregation of heath indices and some socioeconomic variables. CONCLUSIONS: Correlation of segregation of determinants of socioeconomic status with segregation of health indices is an indicator of existence of hot zones of health problems across some provinces. Further studies using multilevel modeling and individual data in health outcomes at individual level and segregation measures at appropriate geographic levels are required to confirm these relations.

Socioeconomic Inequality of Non-Communicable Risk Factors among People Living in Kurdistan Province, Islamic Republic of Iran.

BACKGROUND: The most fundamental way to decrease the burden of noncommunicable diseases (NCDs) is to identify and control their related risk factors. The goal of this study is to determine socioeconomic inequalities in risk factors for NCDs using concentration index based on Non-Communicable Disease Surveillance Survey (NCDSS) data in Kurdistan province, Islamic Republic of Iran in 2005 and 2009. METHODS: The required data for this study are taken from two NCDSSs in Kurdistan province in 2005 and 2009. A total of 2,494 persons in 2005 and 997 persons in 2009 were assessed. Concentration index was used to determine socioeconomic inequality. To assess the relationship between the prevalence of each risk factor and socioeconomic status (SES), logistic regression was used and odds ratio (OR) was calculated for each group, compared with the poorest group. RESULTS: The concentration index for hypertension was -0.095 (-0.158, -0.032) in 2005 and -0.080 (-0.156, -0.003) in 2009. The concentration index for insufficient consumption of fruits and vegetables was -0.117 (-0.153, -0.082) in 2005 and -0.100 (-0.153, -0.082) in 2009. The concentration index for the consumption of unhealthy fat and oil was -0.034 (-0.049, -0.019) in 2005 and -0.108 (-0.165, -0.051) in 2009. The concentration index for insufficient consumption of fish was -0.070 (-0.096, -0.044) in 2005. The concentration index for physical inactivity was 0.008 (-0.057, 0.075) in 2005 and 0.139 (0.063, 0.215) in 2009. In all the cases, the OR of the richest group to the poorest group was significant. CONCLUSION: Hypertension, insufficient consumption of fruits and vegetables, consumption of unhealthy fat and oil, and insufficient consumption of fish are more prevalent among poor groups. There was no significant socioeconomic inequality in the distribution of smoking, excess weight, and hypercholesterolemia. Physical inactivity was more prevalent among the rich groups of society in 2009. The reduction of socioeconomic inequalities must become a main goal in health-care policies.

Survival analysis of patients with gastric cancer undergoing surgery at the iran cancer institute: a method based on multi-state models.

BACKGROUND: Gastric cancer is one of the most common causes of cancer deaths all over the world and the most important reason for its high rate of death is its belated diagnosis at advanced stages of the disease. Events occur in patients which are regarded not only as themselves factors affecting patients' survival but also which can be affected by other factors. This study was designed and implemented aiming to identify these events and to investigate factors affecting their occurrence. MATERIALS AND METHODS: Data from 330 patients with gastric cancer undergoing surgery at the Iran Cancer Institute from 1995-1999 were analyzed. The survival time of these patients was determined after surgery and the effects of various factors including demographic, diagnostic and clinical as well as medical, and post-surgical varuiables on the occurrence of death hazard without relapse, hazard of relapse, and death hazard with a relapse were assessed. RESULTS: The median survival time for these patients was 16.3 months and the 5-year survival rate was 21.6%. Based on the results of multi-state model, age and distant metastases affected relapse whereas disease stage, type and extent of surgery, lymph nodes metastases, and number of renewed treatments affected death hazard without relapse. Moreover, age, type and extent of surgery, number of renewed treatments, and liver metastases were identified as factors affecting death hazard in patients with relapse. CONCLUSIONS: Most cancer studies pay heed to factors which have effect on death occurrence, but some events occur which should be taken into consideration to better describe the natural process of the disease and provide researchers with more accurate data.

Incidence of cancer in Iranian sulfur mustard exposed veterans: a long-term follow-up cohort study.

INTRODUCTION: It is estimated that during the Iraq-Iran war of the 1980s, over 100,000 Iranians (military or civilian) were exposed to sulfur mustard (SM), and a considerable proportion of them are still suffering with long-term consequences of exposure. The aim of the present article is to address carcinogenesis of SM following these acute exposures. METHODS: Using a cohort study, we estimated and compared the incidence rates of malignant disorders in 7,570 veterans exposed to SM and 7,595 unexposed comrades in a 25-year follow-up period. We also determined the hazard ratio of cancer occurrence for SM exposure during the follow-up period. RESULTS: Cancer incidence was significantly increased with exposure to SM. The incidence rate ratio of cancer for SM exposure was 1.81 (95 % CI 1.27-2.56), and the age-adjusted incidence rate ratio was 1.64 (95 % CI 1.15-2.34).The hazard ratio of cancer was 2.02 (95 % CI 1.41-2.88). CONCLUSION: Present study suggests carcinogenesis of SM following acute exposure during war. With respect to this finding, it is reasonable to improve care programs such as routine screening schemes for exposed veterans.

Important Risk Factors of Mortality Among Children Aged 1-59 Months in Rural Areas of Shahroud, Iran: A Community-based Nested Case-Control Study.

BACKGROUND: The aim of the study was to evaluate potential risk factors of children mortality between 1-59 months of age. METHODS: This nested case-control study was conducted among children born from June 1999 to March 2009 in rural areas of Shahroud, located in the central region of Iran using health care visit reports and follow-up data available in household health records. RESULTS: MORTALITY WAS SIGNIFICANTLY ASSOCIATED WITH BREASTFEEDING DURATION (OR: 0.87, 95% CI: 0.81-0.93), total health care visits (OR: 0.90, 95% CI: 0.83-0.98) and low birth weight (LBW) (OR: 7.38, 95% CI: 1.37-39.67). CONCLUSION: In our study, a longer breastfeeding period and more frequent health care visits were two important protective factors, while LBW was an important risk factor for 1-59 month child mortality. It seems, that complex and multiple factors may be involved in mortality of under 5-year-old children, so combined efforts would be necessary to improve child health indicators.

Socioeconomic Status and Incidence of Traffic Accidents in Metropolitan Tehran: A Population-based Study.

BACKGROUND: Population-based estimates of traffic accidents (TAs) are not readily available for developing countries. This study examined the contribution of socioeconomic status (SES) to the risk of TA among Iranian adults. METHODS: A total of 64,200people aged ≥18years were identified from 2008 Urban Health Equity Assessment and Response Tool (Urban HEART) survey. 22,128 households were interviewed to estimate the overall annual incidence, severity and socioeconomic determinants of TAs for males and females in Iranian capital over the preceding year. Wealth index and house value index were constructed for economic measurement. Weighted estimates were computed adjusting for complex survey design. Logistic regression models were used to examine individual and SES measures as potential determinants of TAs in adults. RESULTS: The overall incidence of traffic accident was 17.3(95% CI 16.0, 18.7) per 1000 per year. TA rate in men and women was 22.6(95% CI 20.6, 24.8) and 11.8(95% CI 10.4, 13.2), respectively. The overall TA mortality rate was 26.6(95% CI 13.4, 39.8) per 100,000 person-years, which was almost three times higher in men than that for women (40.4 vs. 12.1 per 100,000person-years). Lower economic level was associated with increased incidence and mortality of TA. Association between SES and incidence, and severity and mortality of TA were identified. CONCLUSION: TAs occur more in lower socioeconomic layers of the society. This should be taken seriously into consideration by policy makers, so that preventive programs aimed at behavioral modifications in the society are promoted to decrease the health and economic burden imposed by TAs.

Evaluation of Tuberculosis Situation in Economic Cooperation Countries in 2009; Achievement and Gaps toward Millennium Development Goals.

BACKGROUND: Evaluating the tuberculosis (TB) status of the Economic Cooperation Organization (ECO) member countries relation to goal 6-c of the third millennium, which includes that TB incidence, prevalence, and death rates should be halved by 2015, compared with their level in 1990. METHODS: In 2009, we have critically reviewed the countries' Millennium Development Goals (MDGs) reports and extracted the data from the surveillance system and published and unpublished data. The main stakeholders, from both governmental and international organizations in the country have been visited and interviewed by the research team as part of the data validation process. RESULTS: The TB incidence is very heterogeneous among ECO countries, which differ from 21.7 in Iran to 230.7 per 100,000 in Tajikistan. TB incidence (per 100,000) is more than 100 in six countries and is from 50 to 100 in two countries and is less than 30 in two countries. Only in two countries the crude death rate (CDR) is higher than 70%. In seven countries the death rate is higher than 10 per 100,000. Two countries are among the 20 top world countries with the highest tuberculosis burden. CONCLUSION: THERE ARE SOME SIGNS AND SIGNALS INDICATING THE BAD CONDITION OF AN ECO MEMBER INCLUDING: incidence of more than 50 per 100000, CDR of less than 70%, death rate more than 10 per 100,000, and rating two member countries among 20 top countries with the highest burden in the world. Iran and Turkey could achieve MDGs by 2015, but if other countries do not prepare urgent intervention programs, they will not be able to fulfill the goals.

Socioeconomic status and mortality after acute myocardial infarction: a study from Iran.

BACKGROUND: Studies have shown an inverse relationship between socioeconomic status (SES) and mortality due to coronary heart disease (CHD). Little is known about this association in Iran. This study aimed to investigate whether mortality after myocardial infarction (MI) varies by SES. METHODS: In a retrospective study, 1283 MI patients who hospitalized in Tehran Heart Center from March 2005 to March 2006 were followed up in March 2008. Demographic, clinical and SES data were collected from case records and by telephone interviews. Multiple logistic regression analysis was performed to estimate the predictive effect of socioeconomic factors on outcome. RESULTS: In all 664 patients were studied. Of these, 500 patients were alive and 164 were dead due to MI (64 died at hospital and 100 died at home). The results of regression analysis showed that in addition to treatment (OR = 9.52, 95%CI 4.84-18.7), having diabetes (OR = 1.78, 95% CI 1.12-2.81) or hyperlipidemia (OR = 1.82, 95% CI 1.14-2.90), socioeconomic variables including living area in square per person (lowest level vs. upper level OR = 4.92, 95% CI 2.11-11.4), unemployment (OR = 3.50, 95% CI 1.50-8.13) and education (OR for illiterate patients = 2.51, 95% CI 1.00-6.31) were the most significant contributing factors to increased mortality after MI. CONCLUSION: Although the findings should be interpreted with caution, the study results indicated that socioeconomic variables were significant contributing factors to increased mortality after myocardial infarction. The underlying role of socioeconomic status on increased mortality after MI deserves further investigation.

Flash flood preparedness in Golestan province of Iran: a community intervention trial.

OBJECTIVE: To evaluate effectiveness of a community-based preparedness program for flash floods. DESIGN: A controlled community intervention trial with preassessment and postassessment. SETTING: Fifteen intervention villages and 16 control villages in Golestan province of Iran. PARTICIPANTS: People more than six years of age. INTERVENTION: Intervention program consisted assembling Village Disaster Taskforces (VDTs), training of VDTs and community, evacuation drill, and program monitoring. MAIN OUTCOME MEASURES: Individual participation in household preparedness actions including, preparedness meeting, risk mapping, preparation of emergency supplies, assisting vulnerable people, and evacuation drill. RESULTS: Our intervention improved preparedness of local community for flash floods in term of all interested outcome measures. For instance, adjusted odds ratio for participation in an evacuation drill in intervention area in postassessment compared with preassessment was 29.05 (95% confidence interval [CI]: 21.77-38.76), whereas in control area it was 2.69 (95% CI: 1.96-3.70). Difference in these odds ratios was statistically significant (p < 0.001). Participation in a family preparedness meeting and risk mapping were helpful in motivating individuals to take other preparedness actions. Women were found prepared as much as the men. Younger people showed lower participation in preparation of family emergency supplies but higher attendance in evacuation drills. Participation in evacuation drills decreased with increasing age. It was a positive association between risk perception and taking all preparedness actions. CONCLUSION: Flood preparedness programs should focus on participatory risk assessment and preparedness techniques, strive to improve risk perception and female capabilities, and ensure providing assistance to the older people during evacuation.

Prediction of intracranial computed tomography findings in patients with minor head injury by using logistic regression.

OBJECT: The aim of this study was to develop a decision rule for physicians in developing countries to identify patients with minor head injury who will benefit from emergency brain CT scanning. METHODS: Three hundred eighteen patients with a history of blunt head trauma and a Glasgow Coma Scale (GCS) score >or= 13 who had presented within 12 hours of trauma underwent nonenhanced brain CT and were included in this prospective study. Computed tomography findings that necessitated neurosurgical care (either observation or intervention) were considered as positive findings. Logistic regression was used to develop the decision rule. RESULTS: Computed tomography scans were always normal in patients < 65 years old who did not have an obvious head wound, a raccoon sign, vomiting, memory deficit, or a decrease in their GCS score. Patients with 1 major criterion (GCS score < 14, raccoon sign, failure to remember the impact, age > 65 years, or vomiting) or 2 minor criteria (wound at the scalp or GCS score < 15) had an abnormal CT scan in 13% of the cases. CONCLUSIONS: The decision rule developed by the authors appears to be 100% sensitive and 46% specific for positive findings on brain CT and will, in developing countries, help clarify the decision to obtain scans.

Overuse or underuse of MRI scanners in private radiology centers in Tehran.

OBJECTIVES: The semiprivate health system in Iran has created an opportunity for unnecessary uses of advanced medical equipments including magnetic resonance imaging (MRI). This study aimed to evaluate the evidence for MRI overuse in private diagnostic imaging centers in Tehran, Iran. The objectives of this study were to determine the frequency of use of MRI scans for different complaints and to explore frequency of normal MRI findings as a function of unnecessary MRI use. METHODS: We conducted a survey among private MRI centers in Tehran, Iran, to study the proportion of MRI scans that may result in significant clinical finding. All MRI reports at a specific point in time at selected MRI centers were reviewed by a physician and the findings were recorded as normal, abnormal, or substantial changes. RESULTS: Of all the MRI reports, 17.2 percent had resulted in normal findings; 9.8 percent ordered for examination of headache, and 4.8 percent for lower back pain. CONCLUSION: Unnecessary MRIs are most likely to result in normal finding; although not all the MRI with normal results could be identified as unnecessary. Negative findings from MRI scans may be reassuring to both clinicians and patients. The proportion of normal findings in MRI scans did not provide evidence of MRI overuse in Iran. The results of this study warrant formation of guidelines for the use of MRIs for headache and low back pain disorders.

Risk factors of breast cancer in north of Iran: a case-control in Mazandaran Province.

INTRODUCTION: Breast cancer is the most common cancer among Iranian women. This study aimed to determine risk factors for breast cancer in the north of Iran. METHOD: A matched case-control study was conducted in Mazandaran province of Iran in 2004 of 250 biopsy proven cases of breast cancer and 500 neighbor controls that were matched by age within a 3 year period. Statistical analysis was carried out using conditional logistic regression with the backward elimination method and crude and adjusted odds ratios with related 95% CIs were estimated with Stata 8.0 software RESULTS: Multivariate analysis showed that higher education (OR=4.70, 95%CI: 1.71-12.88), late menopause (OR=4.18, 95%CI: 2.54-6.88), history of induced abortion (OR=1.62, 95%CI: 1.13-2.31), positive first-degree family history of breast cancer (OR=3.14, 95%CI: 1.37-7.20), and BMI (OR=1.02, 95%CI: 1.01-1.03) were risk factors for breast cancer. Furthermore, having more episodes of full term pregnancy (OR=0.87, 95%CI: 0.80-0.95), longer duration of breast feeding (OR=0.993, 95%CI: 0.989-0.997) and parity more than 2 were shown to be protective factors. CONCLUSIONS: Our study revealed the role of some modifiable determinants of breast cancer that can be focused by public health intervention in the northern community of Iran. Accordingly, the women who have one or more of the following risk factors should take the special attention to risk of breast cancer: obesity, being menopause, positive family history of breast cancer and history of induced abortion. The protective effect of longer duration of breast feeding should be encouraged too.

Distribution of beta-thalassemia mutations in the northern provinces of Iran.

Beta-Thalassemia (thal) is one of the most common autosomal recessive disorders in Iran. There are more than two million carriers of beta-thal and over 15,000 people affected with beta-thal major who live in Iran. Prevalent mutations were identified by examining genomic DNAs isolated from 392 blood samples of beta-thal carriers from three northern provinces of Iran. Furthermore, 172 pregnant women were analyzed from the 196 couples who requested pregnant diagnosis for beta-thal. Allele identification was carried out using routine reverse dot-blot, amplification refractory mutation system (ARMS), and genomic sequencing. The most common mutation, IVS-II-1 (GA), is followed, in order of frequency, by codon 30 (GC), frameshift codons (FSC) 8,9 (+G), FSC 22/23/24 (-AAGTTGG), IVS-I-110 (GA), IVS-I-5 (GC), IVS-II-745 (CG), IVS-I-2 (TC), FSC 8 (-AA), IVS-I,3'-end (-25 bp), IVS-I-1 (GA), FSC 36/37 (-T), IVS-I-6 (TC), FSC 5 (-CT), -28 (AC), codon 37 (GA), IVS-II-2,3 (+11/-2), -30 (TA), and -88 (CA). We have also revealed the existence of five new mutations from northern Iran, one of which (codon 37) is the first reported for Iran. Furthermore, the rate of unknown mutations is significantly reduced in our study (about 6%). These results could help with establishing a center for prenatal diagnosis, prevention, and control of thalassemia in the northern provinces of Iran.

Crimean-Congo hemorrhagic fever in Sistan and Baluchestan Province of Iran, a case-control study on epidemiological characteristics.

OBJECTIVES: Several cases of Crimean-Congo hemorrhagic fever (CCHF), an arboviral disease, have been reported since summer 1999 in different areas of Iran. The main objectives of this research were to determine the most important means and patterns of transmission and the epidemiologic characteristics of this disease. DESIGN: In this population-based case-control study, 24 patients from Zabol and Zahedan Districts in the Sistan and Baluchestan province, reported to the Center for Disease Control of Iran, were compared with 300 controls. The controls were sampled through the 'probability proportional to size cluster sampling' method from the general population of the same districts. The following variables were checked: age, sex, living environment (rural versus urban), education years, job, past history of tick bite, contact history with livestock, history of livestock slaughtering, presence of a designated place for animals at home, history of keeping livestock in the house. RESULTS: Variables which increased the chance of disease include: history of slaughtering (OR = 7.57, CI: 2.21-25.91), high-risk occupations (OR = 4.97, CI: 0.97-25.43), history of tick bite (OR = 105.89, CI: 9.32-1202.44), age above 40 years (OR = 7.32, CI: 1.06-50.26). CONCLUSION: The results of this study confirm that the scheme of risk factors and risk groups for Crimean-Congo hemorrhagic fever (CCHF) in Iran do not differ substantially from the other parts of the world. Even though tick bite is one of the most important risk factors for CCHF, it cannot explain all cases and there are other important risk factors such as high-risk occupations and having contact with livestock. Even taking care of livestock for a short period at home can increase the chance of contracting CCHF.

Long-term pulmonary complications in combatants exposed to mustard gas: a historical cohort study.

BACKGROUND: Sulphur mustard (mustard gas), the most widely used chemical agent in the Iran-Iraq war, affects many organs including the skin, the gastrointestinal and respiratory tracts, and the central nervous system. The aim of this study was to assess the cumulative incidence rate and annual incidence rate of pulmonary complications, and the rate ratio of related factors. METHODS: In a retrospective cohort study of 1337 soldiers with a history of mustard gas exposure, factors such as age, smoking habit, number of exposure episodes, and the use of gas masks were determined, together with an assessment of their relationship to the occurrence of long-term pulmonary complications. All patients residing in the Tehran area were enrolled in the study. Data collection was based on the subjects' medical records and included clinical, spirometric, and in some cases histopathological findings. RESULTS: The cumulative incidence rate of pulmonary complications was 31.6%; the lowest annual incidence rate was noted during the first year of follow-up (0.75/1000), and the highest rate recorded in the seventh year (76.9/1000). Estimated relative risks (RR) for various age groups are as follows: 1.13 (95% CI: 0.88, 1.46) for those aged 21-25 years; 1.49 (95% CI: 1.10, 2.01) for ages 26-30; 1.70 (95% CI: 1.20, 2.40) for ages 31-35; and 2.09 (95% CI: 1.57, 2.77) for subjects aged >/=36. RR with regard to other factors were: more than one versus single exposure 0.69 (95% CI: 0.42, 1.12); smoking versus non-smoking 1.08 (95% CI: 0.80, 1.45), and unprotected exposure versus protective mask use 3.04 (95% CI: 2.20, 4.20). CONCLUSION: The estimated risk of pulmonary complications from war exposure to mustard gas increased with age and for soldiers who had not worn masks.