Journal of School of Public Health and

---

Background and Aim: The purpose of this study was to assess the accuracy of the bootstrap method in logistic regression and to explore the method's use in logistic regression models in cases where the sample size is insufficient.
Materials and Methods: We use data from 150 patients who had undergone surgery at the Cancer Institute, Emam Khomeini hospital during from 1999 to 2001. Then we drew repeated samples of size 50 from these 150 patients.
Results: Applying ordinary logistic regression, an appropriate model we fitted to the initial data. Then confidence intervals and standard errors were computed for all regression coefficients. There are many situations where the sample size is insufficient and conditions for using ordinary logistic regression are not met. In these cases the use of the bootstrap method not only produces more accurate estimations of regression coefficients, but with repeated sampling, produces estimates very close to the true values. This holds for the estimation of regression coefficients, confidence intervals and standard errors of coefficients.
Conclusion: In this study we show the optimal number of replications and the optimal sample size when using the bootstrap method in studies involving relatively small sample sizes.

---

Background and Aim: Responsiveness is of extreme importance in every health system, especially for policy-makers and health managers. Responsiveness relates to how the health system responds to legitimate expectations of the patients regarding non-clinical aspects of health care. Furthermore, justice in an organization requires fair treatment of the patients on the part of the health personnel. In other words, organizational justice relates to how to treat the personnel so that they feel they are treated fairly. The objective of this study was to investigate the responsiveness of hospital as perceived by patients and nurses and the relationship between the responsiveness rate and organizational justice as perceived by nurses in the hospitals.

Materials and Methods: This was a descriptive-analytical study aiming at determining the correlation between responsiveness and organizational justice in 8 elected hospitals (4 private and 4 public) in Isfahan, Iran. The study population was patients and nurses. A total of 320 individuals (160 patients and 160 nurses), selected by stratified random sampling, participated in this study. Two questionnaires, namely the adjusted WHO Responsiveness Questionnaire (for patients and nurses) and the Equity Questionnaire (for nurses), the validity and reliability of both of which had been determined, were used to collect data. The software used for data analysis was SPSS

Results: The overall score (out of 4) of organizational justice was 1.9 0.77, while the mean score of responsiveness as perceived by the nurses and the patients was 2.32 0.54 and 2.48  0.58, respectively. There was no statistically significant difference between the 2 groups with regard to responsiveness, but there was a positive association between responsiveness and organizational justice as perceived by nurses (r = 0.2, p = 0.03).

Conclusion: The variables in the hospitals studied are generally at an intermediate level and there are no statistically significant differences between private and public hospitals. There is no difference in organizational justice between private and public hospitals, but responsiveness is higher in private hospitals as compared to public ones. Thus, the public sector needs to attempt to create more incentives in health professionals in the health sector in order to guarantee higher-quality services and better responsiveness.

---

Background and Aim: Social capital composed of networks, norms and values, which facilitates cooperation within and between groups to achieve mutual benefits and common goals. Social capital increases the benefits of investing in physical and human capital. In a society that favors more social capital, collaboration is easier. This study investigates the validity and reliability of a social capital tool, which had been administered through a large population-based survey using factor analysis.
Materials and Methods: Data were obtained from Urban Health Equity Assessment and Response Tool (Urban HEART-1) survey in Tehran. Factor analysis is a method of discovering structural position of variables to reduce them into a limited number of components which are more fundamental. The reliability of the questionnaire and main components of the tool were investigated through factor analysis.
Results: According to factor analysis, three main components of social capital including, individual trust, cohesion/ social support and social trust/associative relations, were recognized. These three components explained 66.14% of total variance of the social capital tool. Also, overall Cronbach's alpha coefficient was 0.88 which indicates high reliability of the questionnaire.
Conclusion: Social capital tool, which was administered in Urban HEART project, covers the main components of social capital framework with high reliability and validity, which is suitable to be used in other population-based surveys.

---

  Background and Aim: Quality measurement and management has changed to be one of the most important topics in health care today. This study aims to analyze service quality through Importance-performance Analysis tool in selected hospitals.

  Materials and Methods : This is an Analytical-descriptive study. Research community was all admitted patients to four hospitals during a specific period, the sample of the study consists of 284 inpatient person selected by stratified random sampling method. The main instrument was a questionnaire consists of two parts "importance" and "performance" with the same items in 8 dimensions. Assigning the scores for each of those service items in a two-dimensional diagram with four cell, each gives special guideline for hospitals. SPSS 17.0 for windows was employed for the scale measurement.

  Results: The results of the study indicate that the most important dimensions in patients attribute with 3.55 mean were for "accountability" and the best performance in patients point of view was for "responsiveness" and "reliability". The key dissatisfier with least importance and performance score was for "service organization" with the mean of 3.11.

  In analyzing service quality, reliability, empathy, assurance and accountability dimensions were located in Cell I, service process was located in Cell II, service organization was located in Cell III and finally tangibles and responsiveness dimensions were located in Cell IV.

  Conclusion: Application of IPA to these data showed that developing service process management system in order to improve process of service delivering is important directions for hospitals to work on.

---

Background and Aim: Quality of life amongst people living with HIV/AIDS is affected by their experiences such as social isolation, stigmatization and discrimination. Physical, mental and social problems are common throughout their lives. Therefore, studying the quality of life of HIV-infected individuals are shortcomings in various cultural contexts. The purpose of this study was to assess the quality of life of people living with HIV/AIDS in Iran. Materials and Methods: A cross-sectional study design was used. We used convenience sampling to recruit 300 HIV-infected adults attending the Imam Khomeini Hospital consultation center for clients with risky behaviors in Tehran. To collect the data we employed the World Health Organization Quality of life for HIV Brief version (WHOQOL-HIV BREF). T-test, one-way ANOVA, Pearson’s coefficient and multiple regression were used for analysis. Results: The mean ±SD age of the respondents was 34.3±7.5 years. The majority of them were males (55%) and asymptomatic (51.7%). Among the domains of quality of life, Level of independence had the highest score (13.4±3.1), and environment (12.5±2.8) and psychological (12.5±3.1) domains had the lowest. Younger's, women and employed subjects reported better quality of life for different domains of quality of life (p<0.05). Conclusion: Psychological and environment domains in quality of life were found to be adversely affected by HIV. Accurate and culturally sensitive interventions are suggested to address the patients' psychological and environmental needs.

---

  Background and Aim: Considering the uncertainties about associations between orexin-A and obesity, the present study was conducted to determine the effects of 8 weeks of endurance training and high intensity interval training ( HIIT) on plasma levels of orexin-A and some anthropometric parameters in obese adolescent boys.

  Materials and methods: In this semi-experimental project 35 healthy, inactive and obese boys (mean age 15.5±0.69 years, mean body mass index (BMI) = 28.72±2.20, equal to or higher than the 95^th percentile) were randomly divided into three groups of equal numbers, namely, control, endurance training, and HIIT. The endurance training and the HIIT group participated in eight weeks of endurance training (25-40 minutes running per day, with an intensity 65-85% Heart Rate Reserve) and eight weeks of HIIT (30 seconds running with an intensity 90-95% Heart Rate reserve, 4-7 repetitions a day and two minutes of a rest interval with 50-55% Heart Rate reserve), three days per week, respectively. Plasma levels of orexin A, anthropometric measurements (waist-to-hip ratio, body fat percentage and body mass index) and VO2 max were determined before and 48 hours after the last session of the training. Data were analyzed and are reported as mean ± SD using repeated measure ANOVA (p < 0.05).

  Results : Despite a decreasing trend in the plasma orexin-A level in the control and HIIT groups and its rising trend in the endurance training group, no statistically significant differences were observed between the control and experimental groups (P>0.05). However, HIIT and endurance training caused significant reductions in the anthropometric parameters such as body fat percentage (8.7%, 9.7%), body mass index (1.6%, 1.9%) and waist to hip ratio (2.7%, 2.9%), accompanied by a significant increase in the VO2 max (6.7%, 10.9%) (p<0.05).

  Conclusion: Endurance training is more effective than HIIT as regards improvement in body composition of obese adolescent boys, although the changes may not be in line with changes occurring in plasma orexin-A levels. It is recommended that more studies be conducted in this area, controlling sleep, nutrition and changes due to puberty, and with longer durations of exercise.

---

Background and Aim: This study aimed to investigate the association of Internet addiction and self-control with mental health among students of the University of Applied Sciences and Technology (UAST) in Ilam city, Iran.

Materials and Methods: Data collection tools included the Mental Health Goldenberg scale, Tanji Self-control Inventory and Young Internet Addiction questionnaires. The sample consisted of 101 UAST students in Ilam City, Iran.

Results: Analysis of the data showed a statistically significant negative relationship between internet addiction and mental health and a positive association between self-control and mental health in male- and female-students.

Conclusion: It can be concluded that he more a student uses the Internet, the more likely he/she is to be less healthy mentally, while if a student has more self-control, he/she is more likely to be healthier mentally.The use of the Internet among the new generation in the society is spreading, becoming an important part of life. It has been said that teenagers are at a high risk. Hence the responsible authorities should consider mental health as a factor preventing extreme behavior of young people.

---

Background and Aim: Families with diabetic children face various problems and challenges such as child psychological problems, behavioral problems and a low quality of life. The aim of this study was to investigate the effects of promoting the quality of life of parents of diabetic children on clinical symptoms in their children.

Materials and Methods: This was a pre-test and post-test semi-experimental research with a control group. The statistical sample included 32 diabetic children and their parents, selected in 2 stages using the convenience random sampling method from among Tehran Diabetes Association members, randomly assigned to either an experimental or a control group. The experimental group received education about quality of life promotion in ten 2-hour sessions. Data were collected using the child clinical symptoms questionnaire (CSI-4-Child Symptom Inventory) and analyzed by multi-variate analysis of covariance using SPSS 20.

Results: The average post-test scores of emotional-behavioral symptoms in the experimental and control groups were significantly different (F=19.20, F=24.53, F=21.01, P<0.01). Furthermore, the experimental group mean scores were significantly lower than the control values, indicating a positive effect of the comprehensive quality of life promotion program on the children's emotional-behavioral symptoms.

Conclusion: Education about promoting the quality of life imparted to parents of diabetic children can significantly affect clinical symptoms in the diabetic children, decreasing the symptoms. Therefore, such education is recommended in order to promote the quality of life and reduce psychological distress in families of children with diabetes.

---

Background and Aim: Salmonella species is one of the important pathogens causing food poisoning and gastroenteritis. The aim of the present study was to assess the quality of traditional creams as regards bacterial contamination.
Materials and Methods: This was a cross-sectional study including a total of 250 traditional cream and 50 pasteurized cream samples collected in the south of Tehran retail shops. The samples were diluted in a phosphate-buffered saline, transferred to a rappaport-vassiliadis salmonella (rvs) enrichment broth according to the CDC procedures and incubated at 37° C in Hektoen enteric agar and bismuth sulfite agar media for 24 hours. Antimicrobial susceptibility testing was done using the Clinical and Laboratory Standards Institute (CLSI) procedures. On the following day the suspected colonies were examined for phenotype and finally confirmed by the API 20 E test.
Results: Of the 250 unpasteurized cream samples 15 (6%) were contaminated with Salmonella. Of the 7 serotypes identified, the most frequent Salmonella serotype was the infantis serotype with 7 cases (33.3%). Furthermore, Coliform bacteria such as Escherichia coli, Enterobacter, Klebsiella and Citrobacter were also isolated. The highest antibiotic resistance was to nalidixic acid (93.3%), tetracycline (73.3%) and trimethoprim (66.7%). None of the pasteurized cream samples was contaminated with Salmonella.
Conclusion: The results confirm the need for more effective control and monitoring of the traditionally prepared cream marketed in the city by the Food Control Authority. In addition, educating the public about the consumption of pasteurized cream can play a good role in reducing foodborne illnesses.

---

Background and Aim: Healthy food and nutrition have always been a serious concern of human beings. In this regard, food safety is extremely important. As an example, nitrates in foods may affect their safety. The purpose of this study was to investigate the nitrate contents of highly consumed food products (potatoes, tomatoes and onions) on sale in wholesale fruit and vegetable markets (Heravi, Mellat and Lavizan) in District 4 of Tehran, Iran.
Materials and Methods: Samples of the foods were collected in winter and spring, and their nitrate content was measured spectrophotometrically. The SPSS-20 software was used for data analysis.
Results: The results showed that there was a statistically significant difference between the vegetables nitrate contents in winter and spring. The nitrate content of onions in the spring in the Heravi market and that of potatoes in the winter in the Lavizan market were higher than the respective standard, while that of tomatoes was less than the standard in both seasons.
Conclusion: The nitrate content in the samples was in most cases below the respective standard, indicating that the vegetables on sale in the wholesale markets in Tehran were acceptable as regards nitrate content (at least in spring and winter).

---

Background and Aim: Nowadays foodborne diseases are a serious concern globally. Due to unsound use of antibiotics various pathogens are involved in foodborne diseases, S. aureus being the most common cause of food poisoning. Methicillin-resistant Staphylococcus aureus (MRSA) strains are a serious threat for the public’s health worldwide. The objective of this study was to determine the extent of contamination of foods offered in the South of Tehran, Iran with MRSA strains in 2018-19.
Materials and Methods: In this descriptive study, 560 food samples were collected from different regions in the south of Tehran, Shahr-e-Rey and Islamshahr between June 2018 and May 2019 and sent to a laboratory to determine the presence of S. aureus according to the Iranian National Standard No.1194 methods. In addition, the antibiotic sensitivity of the S. aureus species was determined using the Disk Diffusion Test.
Results: Of the 560 samples, 49 (8.7%) were found to be contaminated with S.aureus. Pastry, traditional ice cream and raw protein foods were the most contaminated foodstuffs. Four 4 (8.2%) of the 49 S. aureus isolates were found to be resistant to methicillin.
Conclusion: Considering the importance of S. aureus in causing food poisoning and the possibility of transfer of species resistant to antibiotics, especially methicillin, through foods, it is vital to pay special attention to sound use of antibiotics.