Showing 4 results for Kazemnejad
A Abadi , K Mohammad , M.r Meshkani , A Kazemnejad, Y Mehrabi , F Azizi ,
Volume 2, Issue 1 (2 2004)
Abstract
Misclassification of disease status and risk factors is one of the main sources of error in studies. Wrong assignment of individuals into exposed and non-exposed groups may seriously distort the results in case-control studies. This study investigates the effect of misclassification error on odds ratio estimates and attempts to introduce a correction method. Data on 3332 men aged 30-69 years from Tehran Lipid and Glucose Study (TLGS) were considered for investigating the relationship between angina pectoris and smoking. The “Rose” questionnaire was used to evaluate angina status. Two different definitions of smoking were included: I) active smokers versus non-smokers, II) active and ex-smokers versus never smoked. The relation between variables was assessed both with and without considering misclassification in smoking. Definition I (commonly used in many epidemiologic studies), resulted in a non-significant OR=1.09 (95% CI: 0.84, 1.41). Using the correction method based on the principle of non-differential misclassification, the OR increased to 1.13 (95% CI: 0.89, 1.43), which was still non-significant. However, a correction procedure that included the probability of differential misclassification produced a significant OR=1.46 (95% CI: 1.15, 1.85), p<0.05. It is evident that misclassification in risk factors can lead to inaccurate results. This study showed that the relation between variables may have not been discovered if the probability of misclassification was ignored. Moreover, in case of probable differential misclassification, applying correction methods for non-differential misclassification would be inefficient.
K Azam , A Gerami , K Mohammad , A Kazemnejad ,
Volume 2, Issue 1 (2 2004)
Abstract
In large–scale sampling opeartions (e.g. nation-wide health surveys) we always face the problem of non-response item(s) and/or non-response unit(s). In fitting a model to the data we have two groups of variables, namely dependent and independent variables. Non-response may occur for any of these groups of variables. In this paper we assume Y as a categorical dependent variable with three levels, Z and X as independent variables from any kind: scale, categorical, ordinal, etc. We have complete data on the first two variables and we assume that the missing items follow a random pattern (MAR). Then a model is devised based on the likelihood function for the whole data set (including missing values) and estimates of parameters are compared with those obtained by statistical programs such as SPSS, which are only based on completely observed data and ignore units with missing data. Our results show that the likelihood-based model is superior to the standard approach utilized by the software packages. The comparison is made using data on thyriod disease (goiter) obtained by a health survey in Gazvin province.
H Shahandeh , R Wameghi , N Hatamizadeh , A Kazemnejad ,
Volume 3, Issue 3 (3 2005)
Abstract
Nowadays the Quality of Life (QOL) among different groups of people, especially in disabled
people, is recognized as a very important topic.
In order to assess quality of life in people with spinal cord injuries, 86 members of Tehran
spinal cord injury(SCI) society were selected randomly. Data were gathered through a
questionnaire that consisted of two parts. The first part contained questions about sex, age,
plus the cause, type and duration of injury. The second part contained questions that measured
quality of life in an objective manner. The test was adapted from Lancashire and Wisconsin
tests and modified to suit the cultural background of Iranian people.
Results showed that %73.3 of people with SCI perceived their QOL as good or fair.
In assessing different areas of quality of life, the highest scores were given to social relations
(3.67 out of 5). In the married group the mean score for satisfaction in family relations was
3.95 out of 5 score.
Sub-scores for work/education, finances, physical health and psychological health status were
lower than the other ones.
Results of study indicated that there was a significant difference in the mean QOL score
between the two sexes: the score for women was higher (mean score was 3.3 for women and
2.9 for men). But Quality of Life was not significantly related to age, cause of SCI, type of
SCI, or duration of SCI.
H Zeraati , M Mahmoudi , K Mohammad, A Kazemnejad, M.a Mohagheghi , M.r Mir ,
Volume 3, Issue 4 (4 2005)
Abstract
In recent years the patterns of mortality have changed in Iran, and cancers are playing
a greater role in this regard in this country. Various reports indicate that gastric cancer
is highly prevalent it is the second most common cancer in men, and fourth in the
general population. The purpose of this study was to determine the five-year survival
rate of gastric cancer patients who had undergone surgical treatment at one of the
most important cancer treatment centers, the Iran Cancer Institute, and to assess its
associated factors.
Three hundred and 30 patients with gastric cancer who had been admitted to and
operated on at the Iran Cancer Institute between January 1996 and April 2000 were
enrolled in this study. The patients’ life expectancy after surgery was determined, and
its relationship with variables of age at the time of surgery, gender, and factors related
to the disease such as the cancer site, pathologic type, stage, presence of metastasis,
and sites of metastases were assessed.
The five-year survival rate and the median life expectancy in the studied patients were
23.6% and 19.90 months, respectively. Univariate analysis showed that gender,
cancer site, and pathologic type did not affect life expectancy significantly. But the
five-year survival rate significantly decreases with age. As expected, those involved
with metastasis had a significantly lower five-year survival rate, and the disease stage
significantly affected the patients’ life expectancy (P<0.001). The Cox proportional
hazards model was used to assess the effect of different variables simultaneously, and
it showed that age, distance metastasis, and disease stage influenced the rate of
survival.
Gastric cancer patients in Iran have a low five-year survival rate. One of the most
important reasons seems to be delayed consultation and diagnosis. Most patients are
seen first with the disease in the late stages. At this point, most have lymph node and
liver metastasis which makes treatment even more complex. Thus, it is necessary to
employ mass media for extensive public education about the early warning signs of
the disease and performing periodic examinations.
