• Title/Summary/Keyword: biostatistics

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Comparison of the Family Based Association Test and Sib Transmission Disequilibrium Test for Dichotomous Trait (이산형 형질에 대한 가족자료 연관성 검정법 FBAT와 형제 전달 불균형 연관성 검정법 S-TDT의 비교)

  • Kim, Han-Sang;Oh, Young-Sin;Song, Hae-Hiang
    • The Korean Journal of Applied Statistics
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    • v.23 no.6
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    • pp.1103-1113
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    • 2010
  • An extensively used approach for family based association test(FBAT) is compared with the sib transmission/disequilibrium test(S-TDT), and in particular the adjusted S-TDT, in which the covariance among related siblings is taken into consideration, can provide a more sensitive test statistic for association. A simulation study comparing the three test statistics demonstrates that the type I error rates of all three tests are larger than the prespecified significance level and the power of the FBAT is lower than those of the other two tests. More detailed studies are required in order to assess the influence of the assumed conditions in FBAT on the efficiency of the test.

Modeling of Influential Predictors of Gastric Cancer Incidence Rates in Golestan Province, North Iran

  • Behnampour, Nasser;Hajizadeh, Ebrahim;Zayeri, Farid;Semnani, Shahriar
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.3
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    • pp.1111-1117
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    • 2014
  • Golestan province has a reputation for relatively high incidence rates of gastric cancer in Iran. Along with dietary, lifestyle and environmental influential factors, soil selenium and high levels of pesticide used may exert influence in this region. The present study was designed for modeling the influential predictors on incidence of gastric cancer in Golestan. All registered cases of gastric cancer from March 2009 to March 2010 (49 females and 107 males) were investigated. Data were gathered by both check list and researcher made questionnaire (demographic, clinical and lifestyle characteristics) and analysed using logistic regression. Mean (${\pm}SD$) age at diagnosis was $62.9{\pm}13.8$ years. CIR and ASR of gastric cancer showed 9.16 and 13.9 per 100,000 people, respectively. Based on univariate logistic regression, a history of smoking (OR= 2.076), unwashed hands after defecation (OR= 2.612), history of cancer in relatives (OR= 2.473), history of gastric cancer in first-degree relatives (OR= 2.278), numbers of gastric cancers in first-degree relatives (OR= 2.078), history of X-ray and dye exposure (OR= 2.395), history of CT scan encounter (OR= 2.915), improper food habits (OR= 3.320), specific eating behavior (OR= 0.740), consumption of probable high risk foods (OR= 2.942), charred flesh (OR= 1.945), and animal fat (OR= 2.716) were confirmed as a risk factors. Changes in lifestyle may be expected to increase gastric cancer incidence dramatically in the near future. Therefore, appropriate educational interventions should be designed and implemented by competent authorities.

Health Disparities between Black Hispanic and Black Non-Hispanic Cervical Cancer Cases in the USA

  • Khan, Hafiz Mohammad Rafiqullah;Gabbidon, Kemesha;Abdool-Ghany, Faheema;Saxena, Anshul;Gomez, Esneider;Stewart, Tiffanie Shauna-Jeanne
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.22
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    • pp.9719-9723
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    • 2014
  • Background: Globally, cervical cancer is a major public health concern. Cervical cancer is the second most common cancer among women, resulting in approximately 500,000 cases per year. The purpose of this study is to compare disease characteristics between Black Hispanic (BH) and Black non-Hispanic (BNH) women in the US. Materials and Methods: We used stratified random sampling to select cervical cancer patient records from the SEER database (1973-2009). We used Chi-square and independent samples t-test to examine differences in proportions and means. Results: The sample included 2,000 cervical cancer cases of Black non-Hispanic and 91 Black Hispanic women. There were statistically significant differences between black Hispanic and black non- Hispanics in mean age at diagnosis (p<0.001), mean survival time (p<0.001), marital status (p<0.001), primary site of cancer (p<0.001); lymph node involvement (p<0.001); grading and differentiation (p<0.0001); and tumor behavior (p<0.001). Black women were more likely to develop cervical cancer and to have the highest mortality rates from the disease. Conclusions: Findings from this study show clear racial and ethnic disparities in cervical cancer incidence and prognosis that should be addressed.

Epidemiology Characteristics and Trends of Incidence and Morphology of Stomach Cancer in Iran

  • Almasi, Zeinab;Rafiemanesh, Hosein;Salehiniya, Hamid
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.7
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    • pp.2757-2761
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    • 2015
  • Background: Stomach cancer is the fourth most common cancer and the second leading cause of cancer-related death through the world. It is predicted that the number of new cancer cases will be more than 15 million cases by 2020. Regarding the lack of studies on this topic in the country, we have thoroughly examined the patho-epidemiology of stomach cancer in Iran. Materials and Methods: In this cross- sectional study data were collected retrospectively reviewing all new stomach cancer patients in Cancer Registry Center report of health deputy for Iran during a 6-year period (2003-2008). The study also examined the morphology of common stomach cancers. Trends in incidence and morphology underwent joinpoint regression analysis. Results: During the six-year period, a total of 35,171 cases of stomach cancer were registered. Average age standardized rate for females and males were equal to 7.1 and 15.1 per 100,000 persons, respectively. Most common histological type was adenocarcinoma, NOS with 21,980 cases (62.50%). The annual percentage change (APC) in age-standardized incidence rate (per 100,000) was increase in both females and males at 11.1 (CI: 4.3 to 18.3) and 9.2 (CI: 5.2 to 13.4), respectively. Conclusions: According to our results, the incidence of gastric cancer is increasing in Iran, so further epidemiological studies into the etiology and early detection are essential.

Determination of Lead in Urine by Atomic Absorption Spectrophotometry (원자흡광법을 이용한 요중 연 배설량의 정량)

  • Paik, Nam-Won;Yoon, Bock-Sang;Chung, Kyou-Chull
    • Journal of Preventive Medicine and Public Health
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    • v.7 no.2
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    • pp.377-381
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    • 1974
  • Determination of lead in urine is important in industrial hygiene and toxicology. Dithizone method has been principally used for the determination of lead in urine, which gives accurate results in skilful hands but is usually complex and time-consuming. Atomic absorption spectrophotometry is a new simple method and several procedures have been described. However, the influences of pH and the presence of chelating agents during treatment of lead poisoning are not clear. The purpose of this study was to find out the effect of pH and chelating agents on the determination of lead using Shimadzu atomic absorption/flame spectrophotometer, model AA-610. The results obtained were as follows: 1. The atomic absorption spectrophotometry(AAS) could be applied without prior acid digestion to specimens in the absence of chelating agents. The absorbance at $2,170\;{\AA}$, though more sensitive, was more noisy electronically. Therefore, we selected the wavelength of $2,833\;{\AA}$ plus scale expansion. 2. The optimal pH was in the range from 2 to 3. 3. The sensitivity was $0.075{\mu}g/ml/%$ and detection limit was about $0.2{\mu}g/ml$. 4. In the presence of EDTA, lead could not be completely determined without prior acid digestion. 5. On specimens from patients receiving penicillamine therapy, a comparison was made between the values obtained with dithizone method and AAS method with prior acid digestion. The results of comparison showed a very good agreement.

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Identifying Adverse Events Using International Classification of Diseases, Tenth Revision Y Codes in Korea: A Cross-sectional Study

  • Ock, Minsu;Kim, Hwa Jung;Jeon, Bomin;Kim, Ye-Jee;Ryu, Hyun Mi;Lee, Moo-Song
    • Journal of Preventive Medicine and Public Health
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    • v.51 no.1
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    • pp.15-22
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    • 2018
  • Objectives: The use of administrative data is an affordable alternative to conducting a difficult large-scale medical-record review to estimate the scale of adverse events. We identified adverse events from 2002 to 2013 on the national level in Korea, using International Classification of Diseases, tenth revision (ICD-10) Y codes. Methods: We used data from the National Health Insurance Service-National Sample Cohort (NHIS-NSC). We relied on medical treatment databases to extract information on ICD-10 Y codes from each participant in the NHIS-NSC. We classified adverse events in the ICD-10 Y codes into 6 types: those related to drugs, transfusions, and fluids; those related to vaccines and immunoglobulin; those related to surgery and procedures; those related to infections; those related to devices; and others. Results: Over 12 years, a total of 20 817 adverse events were identified using ICD-10 Y codes, and the estimated total adverse event rate was 0.20%. Between 2002 and 2013, the total number of such events increased by 131.3%, from 1366 in 2002 to 3159 in 2013. The total rate increased by 103.9%, from 0.17% in 2002 to 0.35% in 2013. Events related to drugs, transfusions, and fluids were the most common (19 446, 93.4%), followed by those related to surgery and procedures (1209, 5.8%) and those related to vaccines and immunoglobulin (72, 0.3%). Conclusions: Based on a comparison with the results of other studies, the total adverse event rate in this study was significantly underestimated. Improving coding practices for ICD-10 Y codes is necessary to precisely monitor the scale of adverse events in Korea.

Breast Cancer in Iranian Woman: Incidence by Age Group, Morphology and Trends

  • Rafiemanesh, Hosein;Salehiniya, Hamid;Lotfi, Zahra
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.3
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    • pp.1393-1397
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    • 2016
  • Background: Breast cancer is the most common cancer and the first cause of cancer death in women worldwide, with infiltrating duct carcinoma as the most common morphology. This study aimed to investigate trend of breast cancer incidence by age groups and histological changes in Iranian women between 2003 and 2008. Materials and Methods: This is analytic study, carried out based on re-analysis of the Cancer Registry Center report of health deputy for women's breast cancer in Iran during a 6-year period (2003-2008). Statistical analysis for incidence time trends and morphology change percentage carried out joinpoint regression analysis using the software Joinpoint Regression Program. Results: A total of 36,340 cases were reported for Iranian women in the six years. Analytical trend showed an increasing incidence trend with significant annual percentage change (APC) of 15.2 (CI: 11.6 to 18.8). The lowest and highest significant increased trend were related to age groups of 40 to 44 years and above 85 years, respectively; with APCs of 13.0 and 25.1, respectively. Of total cases, 78.7% of cases were infiltrating duct carcinoma, decreasing from 82.0% in 2003 to 76.6% in 2008, which was significant with an APC equal to -1.76 (CI:-2.7 to -0.8). Conclusions: The incidence trend of breast cancer is rising in Iranian women. The highest incidence was observed in the age groups 45-65 and 80-85. In conclusion, to reduce breast cancer incidence and its burden, preventive and screening programs for breast cancer, especially in young women, are recommended in Iran.

Clustering Asian and North African Countries According to Trend of Colon and Rectum Cancer Mortality Rates: an Application of Growth Mixture Models

  • Zayeri, Farid;Sheidaei, Ali;Mansouri, Anita
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.9
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    • pp.4115-4121
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    • 2015
  • Background: Colorectal cancer is the second most common cause of cancer death with half a million deaths per year. Incidence and mortality rates have demonstrated notable changes in Asian and African countries during the last few decades. In this study, we first aimed to determine the trend of colorectal cancer mortality rate in each Institute for Health Metrics and Evaluation (IHME) region, and then re-classify them to find more homogenous classes. Materials and Methods: Our study population consisted of 52 countries of Asia and North Africa in six IHME pre-defined regions for both genders and age-standardized groups from 1990 to 2010.We first applied simple growth models for pre-defined IHME regions to estimate the intercepts and slopes of mortality rate trends. Then, we clustered the 52 described countries using the latent growth mixture modeling approach for classifying them based on their colorectal mortality rates over time. Results: Statistical analysis revealed that males and people in high income Asia pacific and East Asia countries were at greater risk of death from colon and rectum cancer. In addition, South Asia region had the lowest rates of mortality due to this cancer. Simple growth modeling showed that majority of IHME regions had decreasing trend in mortality rate of colorectal cancer. However, re-classification these countries based on their mortality trend using the latent growth mixture model resulted in more homogeneous classes according to colorectal mortality trend. Conclusions: In general, our statistical analyses showed that most Asian and North African countries had upward trend in their colorectal cancer mortality. We therefore urge the health policy makers in these countries to evaluate the causes of growing mortality and study the interventional programs of successful countries in managing the consequences of this cancer.

Leukemia in Iran: Epidemiology and Morphology Trends

  • Koohi, Fatemeh;salehiniya, Hamid;Shamlou, Reza;Eslami, Soheyla;Ghojogh, Ziyaeddin Mahery;Kor, Yones;Rafiemanesh, Hosein
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.17
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    • pp.7759-7763
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    • 2015
  • Background: Leukemia accounts for 8% of total cancer cases and involves all age groups with different prevalence and incidence rates in Iran and the entire world and causes a significant death toll and heavy expenses for diagnosis and treatment processes. This study was done to evaluate epidemiology and morphology of blood cancer during 2003-2008. Materials and Methods: This cross-sectional study was carried out based on re-analysis of the Cancer Registry Center report of the Health Deputy in Iran during a 6-year period (2003 - 2008). Statistical analysis for incidence time trends and morphology change percentage was performed with joinpoint regression analysis using the software Joinpoint Regression Program. Results: During the studied years a total of 18,353 hematopoietic and reticuloendothelial system cancers were recorded. Chi square test showed significant difference between sex and morphological types of blood cancer (P-value<0.001). Joinpoint analysis showed a significant increasing trend for the adjusted standard incidence rate (ASIR) for both sexes (P-value<0.05). Annual percent changes (APC) for women and men were 18.7 and 19.9, respectively. The most common morphological blood cancers were ALL, ALM, MM and CLL which accounted for 60% of total hematopoietic system cancers. Joinpoint analyze showed a significant decreasing trend for ALM in both sexes (P-value<0.05). Conclusions: Hematopoietic system cancers in Iran demonstrate an increasing trend for incidence rate and decreasing trend for ALL, ALM and CLL morphology.

Comparison of Trend Tests for Genetic Association with Sibship Data (형제 자료에 근거한 유전연관성 추세 검정법의 비교)

  • Oh, Young-Sin;Kim, Han-Sang;Son, Hae-Hiang
    • The Korean Journal of Applied Statistics
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    • v.23 no.5
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    • pp.845-855
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    • 2010
  • Extensively used case-control designs in medical studies can also be powerful and efficient for family association studies as long as an analysis method is developed for the evaluation of association between candidate genes and disease. Traditional Cochran-Armitage trend test is devised for independent subjects data, and to apply this trend test to the biologically related siblings one has to take into account the covariance among related family members in order to maintain the correct type I error rate. We propose a more powerful trend test by introducing weights that reflect the number of affected siblings in families for the evaluation of the association of genetic markers related to the disease. An application of our method to a sample family data, in addition to a small-scale simulation, is presented to compare the weighted and unweighted trend tests.