Introduction to Competing Risk Model in the Epidemiological Research

Background and aims: Chronic kidney disease (CKD) is a public health challenge worldwide, with adverse consequences of kidney failure, cardiovascular disease (CVD), and premature death. The CKD leads to the end-stage of renal disease (ESRD) if late/not diagnosed. Competing risk modeling is a major issue in epidemiology research. In epidemiological study, sometimes, inappropriate methods (i.e. Kaplan-Meier method) have been used to estimate probabilities for an event of interest in the presence of competing risks. In these situations, competing risk analysis is preferred to other models in survival analysis studies. The purpose of this study was to describe the bias resulting from the use of standard survival analysis to estimate the survival of a patient with ESRD and to provide alternate statistical methods considering the competing risk. Methods: In this retrospective study, 359 patients referred to the hemodialysis department of Shahid Ayatollah Ashrafi Esfahani hospital in Tehran, and underwent continuous hemodialysis for at least three months. Data were collected through patient’s medical history contained in the records (during 2011-2017). To evaluate the effects of research factors on the outcome, cause-specific hazard model and competing risk models were fitted. The data were analyzed using Stata (a general-purpose statistical software package) software, version 14 and SPSS software, version 21, through descriptive and analytical statistics. Results: The median duration of follow-up was 3.12 years and mean age at ESRD diagnosis was 66.47 years old. Each year increase in age was associated with a 98% increase in hazard of death. In this study, statistical analysis based on the competing risk model showed that age, age of diagnosis, level of education (under diploma), and body mass index (BMI) were significantly associated with death (hazard ratio [HR] = 0.98, P < 0.001, HR = 0.99, P < 0.001, HR = 2.66, P = 0.008, and HR = 0.98, P < 0.020, respectively). Conclusion: In analysis of competing risk data, it was found that providing both the results of the event of interest and those of competing risks were of importance. The Cox model, which ignored the competing risks, presented the different estimates and results as compared to the proportional sub-distribution hazards model. Thus, it was revealed that in the analysis of competing risks data, the sub-distribution proportion hazards model was more appropriate than the Cox model

Success rate of nonsurgical endodontic treatment of nonvital teeth with variable periradicular lesions

INTRODUCTION: Bacterial infection of tooth pulp can progress into periapical diseases. Root canal treatment has been established as the best treatment. In cases of failure, nonsurgical retreatment of teeth is preferred to surgical procedure and extraction.MATERIALS & METHODS: In this historical cohort study, 104 permanent teeth with apical lesion were treated during 2002-2008. All teeth showed radiographic evidence of periapical lesion varying in size from 1 to >10mm. A total of 55 teeth were treated with initial root canal treatment and 49 teeth required retreatment. Patients were recalled up to ≈7 years. All radiographs were taken by RSV MAC digital imaging set and long cone technique. The presence/absence of signs and symptoms and periapical index scores (PAI) were used for measuring outcome. Teeth were classified as healed (clinical/radiographic absence of signs and symptoms) or diseased (clinical/radiographic presence of signs and symptoms). The data were statistically analyzed using student t-test and Pearson chi-square or fisher’s exact test.RESULTS: The rate of complete healing for teeth with initial treatment was 89.7%, and for retreatment group was 85.7%; there was no significant difference. Size of lesions did not significantly affect the treatment outcomes. Success of tooth treatment did not reveal significant correlation with gender and number of roots.CONCLUSION: Orthograde endodontic treatment/retreatment demonstrates favorable outcomes. Thus, nonsurgical endodontic treatment/retreatment should be considered as the first choice in teeth with large periapical lesion

The Reasons of Entrance Axis Change of Religious Buildings in Isfahan: A Case Study in Sheykh Lotfollah Mosque

What  is important about entrance is the effect of this atmosphere on the circumference physical environment. The reasons of the change of entrance axis of religious buildings in Isfahan are the main objectives of the current study. For detailed analysis, we chose some religious buildings of Isfahan so that they could be a background for further studies. Descriptive analytical approach is used as the research method in this study which analyzed designed environments for entrances and the backgrounds of the buildings. Results show that the Rotation and curvature of the entrance corridor of mosques in Isfahan is not only for importance of Qibla, but it might be for prayers to see a shining spiritual place after passing a Narrow and dark corridor into the praying place

Knowledge, attitude and behavior towards using of microwave oven among women working at Shahid Beheshti University of Medical science and Health service in 2016

Background and Aims: Microwave oven, a household appliance that works with microwave, is one of the essential supplies in the kitchen because of ease and speed in cooking. Microwave users are required to be aware of its safety tips, and women are in the program's top priority due to more involvement. This study aimed to assess the knowledge, attitude and behavior towards using microwave oven amongwomen working at Shahid Beheshti University of Medical Sciences and health services in 2016.Materials and Methods: In this cross-sectional study, totally, 120 women working at Shahid Beheshti University of medical Sciences and Health Services were selected through clustering procedure. All stages of this research were conducted ethically. The consent forms were indeed completed. A reliable and valid questionnaire prepared by the research team was exploited for data collection. The questionnaire encompassed demographic, knowledge, attitude and behavior of using microwave oven questions. Finally, the obtained data was analyzed using SPSS22 statistical Software.Results: The mean age of women was 38.63 ± 9.19 years. About 58.35 percent of participants had associate's, bachelor's level education and 28.35 percent were of Master's degree. Approximately 68.35%of the total study group were married. Overall the mean score of knowledge was 15.80 out of 28. The mean score of attitude was 36.69 out of 50, and the mean score of behavior was 59.62 out of 75. There was no statistically significant relationship between age, marital status, education and knowledge and atti tude.Conclusion: The results of the study suggest the need for interventions to promote awareness, attitude and behavior

Investigation of Climatic Adaptation of Regions for Rosa Damascena Cultivation Using Network Analysis Method (Case Study: Isfahan Province)

Sustainable agriculture requires identification and development of scientific methods that have an important role in optimizing water use, employment and income, community health, and non-oil exports. Significant economical and therapeutic value, market demand and high processing level of medical plants have caused the daily increasing growth of these plants around the world. Considering the climatic and geographical conditions in Iran, the development of these crops, especially in arid areas and semi-arid has doubled. Therefore, in the present study, climatic, topographic and socioeconomic criteria were selected as effective measures in the cultivation of Rosa Damascena and were weighed using the network analysis process and then the ArcGIS was used to digitize and combine the layers. After the formation of the regional spatial database, descriptive information of the maps was added, weighted overlapping in the GIS environment, and finally zoning the areas susceptible to cultivating Rosa Damascena. The results showed that three factors including annual rainfall, altitude, and mean annual temperature had maximum impact and slope parameter had the least impact on the quality and quantity of Rosa Damascena. Moreover, the zoning map showed that 38 percent of northern parts, 15.6 percent of central pats and 11 percent of western parts of the province, have the most suitable sites for Rosa Damascena cultivation

Efficacy of Smoking Cessation on Stress, Anxiety, and Depression in Smokers with Chronic Obstructive Pulmonary Disease: A Randomized Controlled Clinical Trial

Background: Stress, anxiety, and depression have been reported as very common comorbidities in smokers with chronic obstructive pulmonary disease (COPD). This study was aimed to investigate the effectiveness of smoking cessation on stress, anxiety, and depression in smokers with COPD. Methods: Three block-randomized controlled trial groups with a block size of 6 and 9 including guided self-change (GSC) (n = 19), nicotine replacement therapy (NRT) (n = 19), and combined GSC-NRT (n = 19) with a follow-up of 29 weeks were considered in this research. Participants included elderly adult smokers with COPD. The patients carried out 5 weekly GSC counseling sessions and NRT for smoking cessation. Transtheoretical Model (TTM) questionnaire, Fagerstrom Test for Nicotine Dependence (FTND), Depression Anxiety Stress Scale (DASS), the Beck Depression Inventory-II (BDI-II), and Hospital Anxiety and Depression Scale (HADS) as well as the exhaled carbon monoxide (CO) were evaluated over the baseline and 12 and 29 weeks following treatments. Findings: COPD participants with mean of 23 daily cigarette smoking completed the current study. The odds ratio (OR) of smoking cessation in GSC and GSC-NRT groups decreased more than NRT group. In addition, DASS, FTND, and the exhaled CO in GSC and GSC-NRT groups showed a better performance compared with the NRT group. Conclusion: The results showed that GSC and combined GSC-NRT therapy were significantly more effective than NRT alone. Also, the findings showed that GSC, NRT, and combined GSC-NRT were effective on stress, depression, and anxiety decreasing in smoking cessation. It seems that reducing smoking is associated with recovery in stress, anxiety, and depression in smokers with COPD

Introduction to Competing Risk Model in the Epidemiological Research

Background and aims: Chronic kidney disease (CKD) is a public health challenge worldwide, with adverse consequences of kidney failure, cardiovascular disease (CVD), and premature death. The CKD leads to the end-stage of renal disease (ESRD) if late/not diagnosed. Competing risk modeling is a major issue in epidemiology research. In epidemiological study, sometimes, inappropriate methods (i.e. Kaplan-Meier method) have been used to estimate probabilities for an event of interest in the presence of competing risks. In these situations, competing risk analysis is preferred to other models in survival analysis studies. The purpose of this study was to describe the bias resulting from the use of standard survival analysis to estimate the survival of a patient with ESRD and to provide alternate statistical methods considering the competing risk. Methods: In this retrospective study, 359 patients referred to the hemodialysis department of Shahid Ayatollah Ashrafi Esfahani hospital in Tehran, and underwent continuous hemodialysis for at least three months. Data were collected through patient’s medical history contained in the records (during 2011-2017). To evaluate the effects of research factors on the outcome, cause-specific hazard model and competing risk models were fitted. The data were analyzed using Stata (a general-purpose statistical software package) software, version 14 and SPSS software, version 21, through descriptive and analytical statistics. Results: The median duration of follow-up was 3.12 years and mean age at ESRD diagnosis was 66.47 years old. Each year increase in age was associated with a 98% increase in hazard of death. In this study, statistical analysis based on the competing risk model showed that age, age of diagnosis, level of education (under diploma), and body mass index (BMI) were significantly associated with death (hazard ratio [HR]=0.98, P<0.001, HR=0.99, P<0.001, HR=2.66, P=0.008, and HR=0.98, P<0.020, respectively). Conclusion: In analysis of competing risk data, it was found that providing both the results of the event of interest and those of competing risks were of importance. The Cox model, which ignored the competing risks, presented the different estimates and results as compared to the proportional sub-distribution hazards model. Thus, it was revealed that in the analysis of competing risks data, the sub-distribution proportion hazards model was more appropriate than the Cox model

Ataxia in Childhood: Epidemiological, Clinical and Neuroradiologic Features, and the Risk of Recurrence

How to Cite This Article: Javadzadeh M, Hassanvand Amouzadeh M, Sadat Esmail Nejad Sh, Abasi E, Alipour A, Mollamohammadi M. Ataxia in Childhood:Epidemiological, Clinical and Neuroradiologic Features, and the Risk of Recurrence. Iran J Child Neurol.Summer 2017; 11(3):1-6.AbstractObjectiveThis study was conducted on the demographic data, clinical characteristics, electroencephalography, neuroradiological findings, and their impact on the recurrence of ataxia. Materials &amp; MethodsA 3-yr retrospective review of 49 children with ataxia in Mofid Children Hospital, Tehran, Iran was conducted from Apr 2013 to Apr 2016.The demographic, clinical and paraclinical data were recorded in pre-preparedquestionnaires. The patients were also classified in two groups of with or without recurrence and the results were compared. The diagnostic etiologies in our patients were classified as brain tumor, drug ingestion, encephalitis, postinfectious immune-mediated disorders, pseudoataxia, trauma, congenital malformations of the central nervous system and hereditary ataxias. ResultsForty-nine children with ataxia were enrolled. The mean age of the patients with a recurrence of ataxia was more than those without a recurrence.Neurodevelopmental delay in patients with recurrence was more frequent than those without a recurrence. Abnormal findings in the neuroimaging were seen more in the patients with recurrence than those without recurrence. The most common cause of ataxia in patients with recurrence was hereditary ataxia and in patients without recurrence was a viral post infectious disorder. ConclusionAfter a mean follow-up period of 16.36 months (range: 2-37 months), 9 cases (18.4%) showed recurrence. Older age, abnormal neuroimaging, and neurodevelopmental delay should be considered as the risk factors of recurrence of ataxia in children. References1.Piña-Garza JE. Ataxia. In: Piña-Garza JE, editor. Fenichel’s clinical pediatric neurology. 7th ed. Philadelphia: Elsevier Saunders;2013.p.215-35.2.Konczak J, Timmann D. The effect of damage to the cerebellum on sensorimotor and cognitive function in children and adolescents. Neurosci Biohav Rev 2007; 31: 1101-1113.3.Jafar-Nejad P, Maricich SM, Zoghbi HU. The Cerebellum and the Hereditary Ataxias. In: Swaiman KF, Ashwal S, Ferriero DM, Schor NF, editors. Swaiman’s Pediatric Neurology. 5th ed. Philadelphia: Elsevier Saunders;2012.p.939-64.4.Mink JW. Movement Disorders. In: Kliegman RM, Stanton BF, St Geme JW, Schor NF, editors. Nelson Textbook of Pediatrics. 20th ed. Philadelphia: Elsevier;2016.p.2882-96.5.Musselman KE, Stoyanov CT, Marasigan R, Jenkins ME, Konczak J, Morton SM, et al. Prevalence of ataxia in children: a systematic review. Neurology 2014; 82(1):80-9.6.Martínez-González MJ, Martínez-González S, García-Ribes A, Mintegi-Raso S, Benito-Fernández J, Prats-Viñas JM. Acute onset ataxia in infancy: its aetiology, treatment and follow-up. Rev Neurol 2006; 42(6):321-4.7.Benini R, Ben Amor IM, Shevell MI.Clinical clues to differentiating inherited and noninherited etiologies of childhood ataxias. J Pediatr 2012; 160(1):152-7.8.Karimzadeh P, Ghofrani M. A Survey on 100 Children with Acute Ataxia in Mofid Children Hospital Tehran, Iran. Iran RJ 2003; 4(1):7-13.(Full Text in Persian)9.Farghaly WM, El-Tallawy HN, Shehata GA, Rageh TA, Hakeem NA, Abo-Elfetoh NM. Population-based study of acquired cerebellar ataxia in Al-Kharga district, New Valley, Egypt. Neuropsychiatr Dis Treat 2011; 7:183.10.Ryan MM, Engle EC. Acute ataxia in childhood. J Child Neurol 2003; 18(5):309-16.11.Nafissi S, Maghdouri A, Sikaroodi H, Hosseini SS. Epidemiology of Cerebellar Ataxia on the Etiological Basis: A Cross Sectional Study. Acta Medica Iranica 2009; 47(6):465-8.12.Esscher E, Flodmark O, Hagberg G, Hagberg B. Non-progressive ataxia: origins, brain pathology and impairments in 78 swedish children. Dev Med Child Neurol 1996; 38(4):285-96.13.Salman MS, Lee EJ, Tjahjadi A, Chodirker BN. The epidemiology of intermittent and chronic ataxia in children in Manitoba, Canada. Dev Med Child Neurol 2013; 55(4):341-7.14.Weiss S, Carter S. Course and prognosis of acute cerebellar ataxia in children. Neurology 1959; 9:711– 721.15.Teoh HL, Mohammad SS, Britton PN, Kandula T, Lorentzos MS, Booy R, et al. Clinical Characteristics and Functional Motor Outcomes of Enterovirus 71 Neurological Disease in Children. JAMA Neurol 2016; 73(3):300-7.16.Connolly AM, Dodson WE, Prensky AL, Rust RS. Course and outcome of acute cerebellar ataxia. Ann Neurol 1994; 35(6):673-9.