فهرست مطالب

Biostatistics and Epidemiology - Volume:3 Issue: 3, 2017
  • Volume:3 Issue: 3, 2017
  • تاریخ انتشار: 1396/06/25
  • تعداد عناوین: 6
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  • Kazem Mohammad, Mohammad Ali Mansournia, Safoora Gharibzadeh Pages 76-82
    Background and Aim
    Simulation studies are important statistical tools to investigate the performance of statistical models in specific situations. For a binary outcome and exposure, one of the most important statistical measures will be the risk difference (RD). To assess the quality of estimators in estimating the effect of the exposure, a data set with a specific effect measure is require.
    Methods & Materials: Monte Carlo simulation can be helpful in situations when there is a proper data generating process. In this paper, another technique will be presented to generate data with specific marginal risk difference (MRD).
    Results
    Convergence of simulation methods in the same scenario reached in a few iterations using the proposed method.
    Conclusion
    The proposed method is recommended over the current method due to less time consumption; this issue is important in studies with different scenarios.
    Keywords: Data systems, Risk ratio, Causality, Computer simulation, Monte Carlo method
  • Bahar Heydarnia, Mahmoud Mahmoudi, Alireza Teimour, Hesam Abdolhoseinpour Pages 83-87
    Background and Aim
    Quality of life (QOL) is one of the important health components, indicating physical, social, and mental health. Vertebral fracture causes acute and chronic low back pain (LBP), physical disability and decreased QOL, and kyphoplasty is one of the effective methods for treating these types of fractures.
    Methods & Materials: This descriptive cross-sectional study was performed on 48 patients with vertebral fractures who referred for kyphoplasty surgery. Data were collected using two questionnaires, one including demographic information and the other consisting of 36 questions regarding QOL. Data was analyzed using chi-Square and Fisher’s exact tests in the SPSS software. P
    Results
    Of 48 patients, 28 and 20 were women and men, respectively, with a mean age of 64.12 ± 16.99 years. The mean QOL score of patients was 38.28 and 45.8% of the patients had moderate QOL. The mean score for physical and mental health subscales was 30.30 and 50.66, respectively.
    Conclusion
    The mean of total score, the scores of 2 subscales of physical and mental health, and 8 dimensions of the questionnaire were higher among men compared to women. There were significant differences between the two sexes in 2 subscales of physical functioning and health-related disorder. The results of this study showed that LBP and physical dysfunction affected mental health of patients and psychiatric dimensions of the questionnaire.
    Keywords: Low back pain, Spinal fractures, Kyphoplasty, Quality of life, Iran
  • Mahtab Rouhifard, Mehdi Yaseri Pages 88-94
    Background and Aim
    In medical sciences, the outcome is the time until the occurrence of an event of interest. A multi-state model (MSM) is used to model a process where subjects’ transition takes place from one state to the next. For instance, a standard survival curve can be thought of as a simple MSM with two states (alive and dead) and the transition between these two-state models is a method used to analyze time to event data. The most important aspect of this model is that it considers intermediate events and models the effect of covariates on each transition intensity. Some diseases like cancer, human immunodeficiency virus (HIV), etc. have several stages. In the present study, these models were reviewed using cardiac allograft vasculopathy (CAV) data focusing on different approaches.
    Methods & Materials: The data of 576 CAVs were collected. A time dependent simple Cox regression model (CRM) was fitted and a three-state illness-death model was considered for the MSMs.
    Results
    In the simple CRM, only the individuals with the age of > 50 were significant, however for Cox Markov model (CMM) and Cox semi-Markov model (CSMM), the donor’s age > 40, sex, and the individuals with the age of > 50 were other significant covariates.
    Conclusion
    The CMM and CSMM showed more accurate results about risk factors compared to the simple CRM.
    Keywords: Markov chains, Survival analysis, Risk factors, Proportional hazards models, Disease progression
  • Tamanna Kalim, Jena Derakhshani Hamadani, Russell Kabir, Anwarul Azim Majumader Pages 95-105
    Background and Aim

    Intimate partner violence (IPV) is highly prevalent in Bangladesh especially in lower socioeconomic groups. The aim of this research was to identify the prevalence and nature of IPV and determine its association with young children‟s behavior in urban slums.
    Methods & Materials: This cross-sectional survey was conducted on married women with at least one child aged 4-5 years and living with the father of that child (n = 182). The socioeconomic status (SES) questionnaire, the Strengths and Difficulties Questionnaire (SDQ), and IPV questionnaire were used to collect data. The SDQ consists of 4 subscales of difficulties and 1 prosocial subscale. Bivariate correlations and multiple regression analysis were conducted to determine the association of SDQ with IPV.

    Results

    Almost 90% of women had at least once experienced any type of IPV. Some married women had experienced all types of physical, emotional, and sexual violence by their husband throughout their married life. Children, whose mothers experienced IPV, had higher scores of total difficulties on SDQ as well as emotional symptoms and conduct problems compared to those whose mothers did not experience IPV. The study showed that 1 unit increase in emotional violence by the intimate partner independently led to the increase of the total difficulties score by 0.60 units and the emotional symptom problems by 0.28 units (P ≤ 0.05). The regression models showed the 1 unit increase in physical violence by the intimate partner predicted an increase of 0.59 units in the child‟s total difficulties scores (P ≤ 0.05).

    Conclusion

    IPV is widely prevalent in Bangladesh and affects children‟s behavior. The implications for developing policy to educate and intervene are immense and emphasis must be placed on the age appropriate development of exposed children

    Keywords: Intimate partner violence, Children, Bangladesh, Mothers, Poverty areas
  • Mohsen Akhavansepahi, Bibi Leila Hoseini, Yaser Tabarai Pages 106-110
    Background and Aim
    Hypercalciuria is commonly observed in accompany with some conditions. Hypercalciuria can clinically present different symptoms and signs. The diagnostic methods for hypercalciuria have not yet been standardized. The presented study was accomplished with the aim to assess whether random urinary calcium/creatinine ratio (UCa/Cr) could be used as a screening tool for hypercalciuria among children with persistent asymptomatic hematuria.
    Methods & Materials: This cross-sectional study included 100 children with primary hematuria for whom both random and 24-hour urinary evaluations were performed. Pearson correlation coefficient (PCC) was used to assess the correlations.
    Results
    There was a moderate correlation between random UCa/Cr and 24-hour urinary calcium excretion (UCaE) (r = 0.511, P
    Conclusion
    24-hour urinary analysis is preferred to random UCa/Cr. Random UCa/Cr is not appropriate for screening hypercalciuria among children with persistent asymptomatic hematuria.
    Keywords: Hypercalciuria, Hematuria, Child, Urinary tract, Calcium, Creatinine
  • Morteza Akbari, Akbar Bagheri, Mohammad Moradi, Atiyeh Rafinejad, Javad Rafinejad Pages 111-116
    Head lice are considered as mandatory ectoparasites living on human head hair, which are transmitted to others through direct physical contact. This disease is mostly seen among children. In this review study, search was conducted among all studies performed in the past 20 years and studies were selected and reviewed. Contributing factors like location, study year, etc. were analyzed to procure a national management guideline. The finding of the present study showed that age, gender, parent's education, parent's job, family size, and presence of health inspector at schools were of statistical positive significance. However, hair type, hair length, dandruff, woven hair, and hair oil application showed no effect on head lice infestation. Head lice could be managed significantly regarding educational health and personal and public principles, especially regarding head lice biology and epidemiology to students, teachers, and parents.
    Keywords: Pediculosis, Lice infestation, Head louse, Iran