مجله اپیدمیولوژی ایران
سال پانزدهم شماره 1 (پیاپی 53، بهار 1398)

Chronic renal failure (CRF) is an irreversible disorder of the renal function. The aim of this study was to  describe the features of patients with chronic renal failure and the factors associated with this disease among hemodialysis patients in a hospital in Tehrn in 2016.
  In this cross-sectional descriptive study, patients presenting to the hemodialysis department of Shahid Ayatollah Ashrafi Esfahani Hospital who underwent continuous hemodialysis treatment for at least three months were studied. Data were gathered from the medical records of the patient s and, if necessary, additional interviews were conducted with the patients. Data were analyzed with descriptive and inferential statistics using the Stata software version 14.
  Of 359 patients, 230 (64.07%) were male with a mean age of 58.1 ± 1.09 years. The frequency (frequency percentage) of the most commonly known possible causes of renal failure was hypertension 91 (25.35%), hypertension and diabetes 84 (23.43%), and diabetes 78 (21.73%). The mortality rate was higher in diabetic patients compared to non-diabetic patients (50% vs 38.55%).
  The main cause of chronic renal failure is hypertension and diabetes, and the mortality rate is higher in these patients than in other patients.

A considerable number of clinical trials are conducted in Iran each year. Not much is known about the characteristics of them, this study aimed to investigate key characteristics of Iranian clinical trials.
  All clinical trial protocols registered in IRCT until November 2013 were selected. Text mining techniques were used to extract information from data that was mostly in the textual format. Stata software (v. 11) was used for both extraction and analysis.
  Totally 5049 trials where analyzed. Trials were in 40 different areas of medicine and their annual number was increasing. The sample size of registered trials was less than 70 in most trials and showed no significant improvement during the 5-year period (Median sample size= 64, inter quartile range (IQR) = 40-100). Phase III trials comprised 8.4% of the trials with a median sample size of 75 (IQR= 50-120). Of all phase III trials, 69% had a target sample size of less than 100. Most trials used randomization techniques (87.2%) but failed to use placebo (65.3%) and double/triple-blinding techniques (55.8%). The leading sponsors for 99.9% of trials were national bodies and 92.2% of the trials received public funds. Only 1% of the trials were exclusively sponsored by pharmaceutical companies.
  The majority of clinical trials conducted in Iran are investigator-initiated and are funded by the public sector. The small sample size and failures in bias control observed in the majority of trials highlights the need for revising current policies of conducting trials in Iran.

To preventing deaths, it is essential to recognize factors affecting the survival of road accident victims. This study was conducted to identify the factors affecting the mortality of road accident victims.
  All pre-emergency mission forms and hospital records of road accident victims were analyzed. The dependent variable was the time interval between the accident and death or discharge from hospital. The forms included demographic variables, accident location, injury status, type of vehicle, type of trauma, mission time, and vital signs.
  Of 8920 injured persons, death occurred in 143 (95% CI: 0.014-0.019). Being over 65 years (Hazard Ratio (HR) 7.6, 95% CI: 3.14-18.4), accident on the main roads (HR 1.44, 95% CI: 0.6-3.5), tracheal intubation (HR 26.4, 95% CI: 3.05-227.6), a systolic and diastolic blood pressure above 100 (HR 0.4, 95% CI: 0.4-0.12) and 70 mm Hg (HR 0.53, 95% CI: 0.24-1.2), and heart rate>100/min (HR 3.0, 95% CI: 1.7-5.1) were associated with the risk of death.
  In providing services, age, status of blood pressure, pulse, injury status, and type of trauma can affect the patients’ survival.

Suicide is one of the psychosocial problems in Lorestan Province due to its socio-cultural and economic structure. The aim of this study was to investigate the effect of age group, time period, and birth cohort on the suicide incidence in Lorestan Province during the 2006-2015.
  In this study, to overcome the identifiability problem, the Carstensen approach and natural cubic smoothing character were used in age-period-cohort models (APC). Cohort effect was calculated as the relative rate from the 1984 reference cohort for men and 1987 cohort for women. The period effect in both sexes constrained to be relative to 1390 and to be 0 on average with 0 slope. The best APC model for both sexes was the models with "AC-P" parameter, 7 knots, and natural splines for men and B splines for women. All analyses were performed using the R software with Epi package.
  The age effect showed that the highest suicide incidence rate was seen in the elderly. Two strong birth cohort effects were observed, one increasing one in the 1980 cohort and one decreasing one in 1991 cohort. The most significant period effect was seen in men in 2011.
  The effects of 1991 and 1980 birth cohorts could be due to the consequences of imposed war in Iran. The three economic phenomena, oil price change, increased divorce rate, and increased unemployment rate can be effective in the emergence of the period effect in year 2011.

The prevalence of HBV infection among injection drug users (IDUs) is higher than the general population due to high-risk sexual behaviors and the needle sharing. The aim of this study was to determine the prevalence of HBV infection and its effective factors among IDUs of Kermanshah Province in 2016.
  This ia descriptive-analytic study was performed in 606 male IDUs in Kermanshah Province in 2016. Data were collected through questionnaires and interviews. HBV was also evaluated through blood tests using the rapid test. Simple and multivariate logistic regression analyses were applied to investigate the factors affecting HBV infection. Data were analyzed using STATA-12 software.
  The prevalence of positivity HBV antibody was 3% (95% CI: 1.61- 4.32) among male IDUs. According to the results of unit-variable logistic regression analysis, the duration of drug injection (OR = 1.08, 95% CI: 1.02-1.15) and the number of daily injections (OR = 1.38, 95% CI: 1.05-1.81) were risk factors for HBsAg positivity but there were no significant associations in the multivariate regression model.
  The prevalence of HBV is much higher among IDUs than in the general population. These populations are at risk for viral infections such as HBV; therefore, it is recommended to provide necessary education about the prevention methods as well as the necessary screening for them.

The Family Physician (FP) plan was implemented in rural areas and cities with a population of less than 20000 in 2005. The purpose of this study was to explain the challenges and obstacles of the Rural Family Physician Program in Kurdistan Province from the perspective of stakeholders.
  This qualitative study was conducted using 30 semi-structured interviews and 5 focused group discussions (FGD) with stakeholders of the FP plan from June 2017 to Jan 2018. The participants were selected through a purposive sampling method with maximum variation. The contents of the interviews and FGD were categorized by the content analysis method using MAXQDA10 software (V. 10).
  The challenges and obstacles of the FP plan were categorized into 16 subcategories and 5 main categories. The main categories were stewardship challenges, service delivery challenges, cultural and educational challenges, human resource challenges, and infrastructure challenges. The most important subcategories of these challenges included weaknesses in policy-making, formation of laws and regulations, weaknesses in insurance performance, weaknesses in intra-sector coordination, weaknesses in the referral system, weaknesses in communicating the plan to the community, low survival of physicians, inadequate motivational mechanisms, and weaknesses in the information system.
  The rural FP plan faces many challenges that require multi-dimensional interventions. Identifying the challenges of the FP plan from the perspective of its stakeholders can help to gradually improve the plan.

This research was conducted to investigate the socioeconomic and geographical inequality in mortality from road traffic accidents in Iran in 2016.
  In this descriptive cross-sectional study, the data of 16,584 people that died from road traffic accidents in 2016 were received from the Legal Medicine Organization. Theil entropy index was used to determine inequality in geographic areas. Moreover, relative and absolute concentration indices were used to measure inequality in mortality from RTAs across educational levels.
  The mortality rate from road traffic accident was 21.5 per 100,000 people. Theil index was 0.66 for traffic-related deaths among the provinces, indicating an unequal distribution of traffic injuries caused by traffic accidents among the provinces. When inequality was measured at smaller geographical levels, i.e., among cities in each province, the results indicated a fair distribution across smaller geographic levels. The focus index also indicated a fair distribution of traffic accidents among the deceased sub-classes (concentration index & 95% CI: -0.13 (-0.41; 0.16).
  Our findings showed that the distribution of mortality from road traffic accidents was unequal at provincial positions. According to our findings, mortality from traffic accidents was distributed equally among the socioeconomic and urban levels. Therefore, health managers can use the findings of this study to develop interventions to reduce inequalities. In addition to targeting factors contributing to known social inequalities in the health and social status, other factors should be considered and applied to evaluate their interventions in the future.

One of the most important determinants of the fertility level is the birth interval. Considering the importance of this issue, the aim of this study was to analyze the first and second birth intervals using shared frailty survival model and comparing factors affecting these intervals.
  Probability proportional to size stratified sampling was used to select 610 married women aged 15-49 years from different regions of Tehran during the winter and spring of 2017. Data were collected using a structured questionnaire. The shared frailty survival model was fitted to investigate the effect of calendar period, age at marriage, education level, education level of the spouse, job and migration status, household costs, and place of residence on first and second birth intervals.
  The median length of the first and second birth interval was 38 and 55 months, respectively. Calendar period had a significant effect on the first birth interval (p-value=0.016). Job status (p-value=0.045) and place of residence (p-value=0.025) had a significant effect on the second birth interval. The hazard rate  of the first birth interval for women in the recent calendar period compared to women in the first period was equal to 0.448, and the hazard rate of the second birth interval for employed compared to unemployed, living in developed versus undeveloped regions was 0.812, and 0.724, respectively
  Delayed childbearing among young women and longer second birth intervals in employed women may result from economic and social conditions that can be prevented by providing appropriate conditions.

Highly pathogenic avian influenza (HPAI) viruses are particularly important due to huge economic consequences and public health concerns. During recent years, because of the severity of epidemics and failure in the control and eradication of HPAI, vaccination has been introduced into the National Prevention and Control Program of some countries, including Iran. This article discusses the role of vaccination in the control of HPAI, the characteristics and constraints of the vaccine, types of commercial vaccines, and previous experiences.
  Scientific databases were searched to collect essential evidence on the role of vaccination in controlling HPAI in a variety of poultry and birds with no time and language restrictions. The articles related to the efficacy and effectiveness of the commercial vaccines on at a national level or population-based studies in some farms were included in present study.
  Because of the high pathogenicity and variability of the influenza virus as well as the shortcomings of some commercial vaccines in prevention of virus transmission, vaccination should only be taken into consideration when all other methods of disease control are ineffective. The consequences of the use of vaccines containing the seeds non-antigenically matched with the circulating strains have been reported frequently.
  In the national vaccination program, informed policymaking requires evidence based vaccinology that can facilitate development of the national infrastructure with awareness of the limitations of commercial vaccines and the realistic expectations of logistic, financial, and human resources.

Cervical cancer is one of the five most common cancers in Iranian women. Considering the impact of HIV on cervical cancer and the low rate of cervical cancer screening in HIV positive women, this study was conducted to review the barriers to cervical cancer screening in HIV positive women.
  In this systematic review, data were retrieved from Magiran, SID, Irandoc, Prequest, OVID, ScienceDirect, PubMed, Web of Science and Scupos databases from January 2000 to January 2018. The following keywords and their combination were used: cervical cancer screening, Pap smear, HIV-positive women, and barriers. The NOS (Newcastle-Ottawa Scale) checklist was used to evaluate the quality of the selected articles and the articles that scored more than six were included in the study.
  From 145 selected articles, 21 were included in the review based on the inclusion criteria. The most common reported screening barriers were the costs of test, lack of awareness, low education level, younger age, lack of information about screening centers, and fear of sampling. 
  Considering the barriers to cervical cancer screening, increasing the level of awareness of the HIV-positive women, preparing free Pap smear services, and providing easier access to health centers for this high risk group could lead to early detection of cervical cancer.

Leishmaniasis control in each country, especially in countries where the disease is endemic, requires designing and implementing an organized national surveillance system. Iran has long been considered as an endemic country for leishmaniasis. The purpose of this study was to review the leishmaniasis surveillance system in Iran.
  In this review study, the data were obtained from the surveillance system, reports and documents, published guidelines, reviews of the existing structures, and the views of the managers and experts of the Center for Communicable Diseases control in Iran in 2018.
  The surveillance system for two types of leishmaniasis, cutaneous leishmaniasis and visceral leishmaniasis (Kala-azar), is currently operational in the country, and new cases are reported monthly. For each identified case, in addition to the epidemiologic attributes, treatment and follow-up as well as follow-up of possible contacts are done as per to the guidelines for each of these diseases.
  The current surveillance system for leishmaniasis has improved the process of reporting cases in recent years. However, the low rate of reporting of cases, especially for cutaneous leishmaniasis, and epidemiological complexities in the transmission of the infection indicate the need for reviewing and improving the current surveillance system.  Data from the surveillance system and the increasing number of leishmaniasis cases in Iran reveal the need for innovations to strengthen the control measures for this disease.

This article provides an overview of the national nosocomial infection surveillance system in Iran and its current status, achievements, and challenges.
  All relevant reports, documents, and program guidelines, as well as published literature and surveillance data related to the nosocomial infection surveillance system in Iran were critically reviewed. Opinions of the key informants at local and governmental levels were also reviewed.
  The program was launched in 2006 covering 100 volunteer hospitals. Since 2016, participation in the program is obligatory, leading to the participation of 555 hospitals with >100 beds (56%). Major data collected in the program include demographic characteristics, infections and related risk factors, pathogens and their antimicrobial susceptibility/resistance, and patient outcome. Recently, device-associated infection rates are also calculated in the program. Since its establishment in 2006, the program has improved in terms of case finding and coverage. Implementation of the program has also had positive impacts on the stakeholders’ knowledge, attitude, and practice.
  Although the number of identified cases and program coverage have improved, a considerable proportion of the infected cases still remain undiagnosed. Implementation of the program has also improved the stakeholders’ awareness, attitude and practice. The program faces a number of challenges, including lack of appropriate scientific support from academics and executive issues. Integration of active and sentinel surveillance in selected hospitals, persuasion of physicians to actively participate in the program, and conducting incidence and prevalence surveys would help the program to better detect nosocomial infection cases.