مجله اپیدمیولوژی ایران
پیاپی 1 (پاییز 1384)

Epidemiological studies of cancer is the corner stone of cancer control plans and necessary for setting goals, monitoring the progress, and evaluating the results of control efforts. Cancer is a generic name for a number of diseases that have different etiology, natural history, and outcome. Thus, control activities for each cancer is different and requires varied approaches. Primary prevention, i.e., controlling the initiation of cancers is now possible for a number of cancers including lung, stomach, liver, and cervix by controlling the use of tobacco, and infections with Helicobacter pylori, Hepatitis C, and Human papilloma viruses. Secondary prevention, i.e., early detection is mostly effective for the cancers of the breast (mammography), cervix (Pap test), prostate (digital rectal exam and PSA testing), colon and rectum (Colon- and Sigmoidscopy), and melanoma of the skin (clinical examination of the skin). Effective treatment is now possible for a large number of cancers with arrays of new medications such as Tamoxifen and Herceptin for breast cancer, Avastin for Colorectal and other cancers, and so on. Tertiary prevention, i.e., rehabilitation and hospice care is a necessary part of cancer control that is generally neglected. Cancer is a familial disease and when it struck, it affects the whole family. Health education and social support for the patients and their families is an integral part of cancer control activities and must be present in any effective cancer control program. Tertiary prevention not only includes proper palliative care, but also education and support for proper nutrition and improvement of the quality of life for the patient and the family.

A "healthy human being" is the cornerstone of stable development in every country. Thus, an important part of the development process is the nutritional improvement of the society. Although a great proportion of the familie's income is spent on food, nutritional problems are still prominent in this country. This fact demonstrates that diets are mostly influenced by the education and knowledge of the households, rather than any new developments in food production. This study was designed to investigate the knowledge, attitude and practices of the households and health care providers regarding nutrition and micronutrients in provinces of Boushehr, Golestan, and Sistan and Balouchestan. The results of this study can help the Community Nutrition Office in the design and effective implementation of interventions aimed at improving nutritional health in households. The sampling method for households was the single-stage cluster sampling with equal-sized clusters. The sampling method for health staff was stratified random sampling. The number of samples in each stratum was proportion to its size. A total of 2304 households and 360 health care workers were selected for this study.The data were gathered through a structured questionnaire and via interviews with eligible people in each household, and also some levels of health staff. At the level of the health staff, physicians and other health professionals, data collection was done through self-administered questionnaires.

To compare three different methods of signal detection applied to the Adverse Drug Reactions registered in the Iranian Pharmacovigilance database from 1998 to 2005. All Adverse Drug Reactions (ADRs) reported to Iranian Pharmacovigilance Center from March 1998 through January 2005, were included in the analysis. The data were analyzed based on three different signal detection methods including Reporting Odds Ratios (PRRs), Bayesian Propagation Neural Network (BCPNN) and Reporting Odds Ratios (RORs). Signals detected by each method were categorized based on the number of reports per drug-adverse event combination, severity of the event and labeled or unlabeled ADRs. The methods applied to signal detection were then compared in recognizing different types of adverse events. A total of 6353 cases of ADR reports, describing 11130 reactions, were reported to Iranian Pharmacovigilance Center (IPC) during the study period. The dataset involved 4975 drug-event combinations, which were assessed for detecting signals. The counts of drug-event combinations was 1, 2 and 3 or more for 3470, 727 and 779 combinations, respectively. There were 500 drug items responsible for 468 reaction terms in the database. According to PRR and 95% Confidence Interval, there were 2838, 872 and 488 drug-event combinations known as a signal for the pairs with the reporting frequency of ³1, ³2 and ³3 reports, respectively. The signals detected with the criteria of PRR³2, c2³4 were 2930, 872 and 480 for the pairs with the same reporting frequencies. Estimates of RORs and the 95% Confidence Interval showed that 2722, 862 and 481 drug-event combinations were detected to be signal for the pairs with the reporting frequency of ³1, ³2 and ³3 reports, respectively, while measuring IC and IC-2SD detected 1120, 378 and 235 cases for the same reporting frequencies. There were 234 signals detected by all three methods. Despite the similarities between data mining methodologies for signal detection, there are differences in the numbers of signals detected by each method. The study findings suggest that quantitative signal detection methods should be added to the routine Pharmacovigilance activities in Iran and the trends for quantitative measures over time should be monitored.

Road traffic injuries are among the most important causes of death and disability in Iran, and the country has one of the highest prevalence of opioid drug use, especially among drivers. The effect of different situations related to opioid use needs great attention. The purpose of this study was to estimate the effect of driving in the withdrawal phase on the occurrence of traffic accidents leading to injury. This is a Case-Crossover study on injured drivers of crashed motor vehicles in Kerman. Drivers having skipped one habitual drug dose within one hour of the driving session were considered as being in withdrawal. We compared the driver's situation at the time of accident with their regular driving habits. Among 75 drivers who had history of regular use of opium, 15 were in withdrawal phase at the time of accident. The relative rate of occurrence of traffic injuries while driving in these circumstances was 2.67 (95% confidence interval: 1.52 - 4.68). According to these findings we can conclude that habitual opioid users are at greater risk of traffic accidents while driving in withdrawal status; this risk is more than two-fold relative to not being in withdrawal status.

On 26 December 2003, an earthquake measuring 6.5 on the Richter scale struck the city of Bam and the surrounding villages. This study was conducted to determine the needs of the affected population on the 19th and 20th days after the quake to help with the prioritization of relief activities and efficient resource allocation. Following a feasibility study on 10 Jan 2004, a team consisting of volunteer students of School of Public Health at KUMS was assembled and trained. Each of the 8 groups consisted of 3-4 students with at least 1 man responsible for security on the field. On the 13th and 14th of January, using a cross-sectional design, 60 clusters including 420 households, 7 households in each cluster, were studied based on a Cluster Geographic-Based Sampling (GBS) Plan. Fifty-five households (13.1%) had children < 2 years, 81 (19.3 %) had children aged 2-5 years and 68 (16.2 %) contained people more than 65 years old. Thirty-seven households (8.9%, CI 95%: 6.4-11.7%) had changed their residence in Bam from one zone to another; the main reason for this was poor environmental health conditions (85%). The main source of health and social messages for families was word of mouth 284 (67.6%). The most commonly needed items were bathrooms (73.8 %, CI 95%: 68.9-78.7%), food (68.8 %, CI 95%: 62.6-75.0%) and warm clothes (67.4 %, CI 95%: 60.9-73.8%). The most frequent illness was acute respiratory infection (59.8 %, CI 95%: 54.3-65.2%). Two hundred households (47.6%, CI 95%: 42.6-52.6%) complained of difficulties in obtaining health and medical services. The main barrier to access was transportation problems due to long distance (38.1%, CI 95%: 35.6-40.6%). We conclude that relief operations should be continued to provide basic public health facilities. Active delivery of health and medical services should be strengthened, and problems related to reproductive health should not be ignored. The GBS plan is a useful tool in the post-disaster surveys. Using volunteer university students was a rewarding experience and teaching and application of "Disaster Epidemiology" should be improved in this country.

The campaign to eliminate measles and rubella (MR) is one of the most important current health projects in Iran. One of the basic requirements of this program is the creation of an efficient system for collecting data on MR morbidity and mortality, people's knowledge, attitude and practice (KAP) regarding MR prevention, and people's participation in the eradication drive. The present study was done to assess people's knowledge, attitude and practice in relation to the current anti-MR campaign. This cross- sectional study was carried out fur months after the mass (anti-MR campaign (performed in May 2004). The target population included at the people aged 20-25y who lived in areas covered by Tehran University of Medical Sciences and Health Services. The calculated sample size was 384, using a 2-stage sampling procedure. We used X2 tests, odds ratios and confidence intervals to detect relationships between various categorical variables. We also performed Cronbach's alpha test to assess questionnaire reliability, and principal component analysis to ensure construct validity. Data were collected on 390 individuals. The percentages of people with an acceptable level of knowledge, attitude and practice were 63.3%, 53.6% and 93.1% respectively. After controlling for confounders in a logistic regression model, it became apparent that knowledge concerning the mass immunization campaign was related to the individual's own education and that of his/her mother. Attitude was found to be affected by factors such as education, marital status and the family's main income level. The practice component, on the other hand, was not significantly related to any of the variables included in this study. The positive achievements of this program should be used in planning any future immunization campaigns. Particular attention should be paid to factors that affect overall coverage. These include human resources, equipment, vaccines and other materials, service uality, the cold chain, information provided to the public, and people's as well as provider's knowledge of the immunization program, the target diseases (s) and the vaccines.

Noise-induced hearing loss is a prevalent work-related morbidity in the country. We determined the strength of association between hearing loss and occupational noise exposure as the first step in prevention programs. A historical cohort study involving 100 exposed and 31 non-exposed subjects was conducted. Noise exposure was estimated using sound level meter BSEN 60651, Type 2. Past noise exposure was estimated using the existing data on the place and type of work. Audiometry was used to assess hearing loss in each subject in 3- year intervals on an occupational cohort from 1993-2004. Noise-induced hearing loss was found in 49% (49 subjects) of the exposed group and 9.7 %(3 subjects) of non-exposed group (p<.0001). Nobody used any form of hearing protection routinely in either group. Relative risk for noise-induced hearing loss was 5.1(CI95%: 1.7- 15.1).Time at risk was estimated 24.9 years (22.7-27.1) in exposed and 22.2 years (20.7-23.7) in unexposed group by survival analysis. More legislation, hearing conservation programs, and surveillance and biological monitoring of work sites and workers are required to prevent occupational hearing loss. Planning strategies for noise assessment and control can help improve the work environment. Gross occupational exposure to noise has been demonstrated to cause hearing loss and the authors believe that occupational hearing loss in the country is a widespread problem.

Missing data exist in many studies, e.g. in regression models, and they decrease the model's efficacy. Many methods have been suggested for handling incomplete data: they have generally focused on missing outcome values. But covariate values can also be missing. In this paper we study the missing imputation by the EM algorithm and auxiliary variable and compare the result with case-complete analysis in a logistic regression model dealing with factors that influence the choice of the delivery method.Our data came from a cross-sectional study of factors associated with the choice of the delivery method in pregnant women. The sample size in this cross-sectional study was 365 and the data were collected through interviews, using questionnaires covering several demographic variables, delivery history, attitude, and some social factors. We used standard deviations to compare the efficiency of the two methods. The results show that maximum likelihood analysis by EM algorithm is more effective than case-complete analysis.The problem of missing data is common in surveys and it causes bias and decreased model efficacy. Here we show that the EM algorithm for imputation in logistic regression with missing values for a discrete covariate is more effective than case-complete analysis. On the other hand if missing values occur for a continuous covariate then we have to use other methods or change the variable into a discrete one.