• Title/Summary/Keyword: biostatistics

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Overview of Childhood Cancers at a Regional Cancer Centre in North-East India

  • Hazarika, Munlima;Krishnatreya, Manigreeva;Bhuyan, Cidananda;Saikia, Bhargab Jyoti;Kataki, Amal Chandra;Nandy, Pintu;Hazarika, Monalisha;Roy, Partha Sarathi
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.18
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    • pp.7817-7819
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    • 2014
  • Childhood cancers are relatively uncommon in comparison to adult cancers. There is no literature available to shed light on clinic-pathological types and patterns of care for childhood cancers in our population in North-East India. In this analysis we therefore tried to determine the common childhood cancers diagnosed in our institute, clinical profile of the patients, types of treatment and compliance, and median survival estimates. Leukemia was most common, followed by retinoblastoma, central nervous system tumours and lymphomas. Ascertaining the clinic-pathological profile of childhood cancers in our population is essential for allocation and management of resources for this small but important group of patients.

Prediction of Conditional Variance under GARCH Model Based on Bootstrap Methods (붓스트랩 방법을 이용한 일반화 자기회귀 조건부 이분산모형에서의 조건부 분산 예측)

  • Kim, Hee-Young;Park, Man-Sik
    • Communications for Statistical Applications and Methods
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    • v.16 no.2
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    • pp.287-297
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    • 2009
  • In terms of generalized autoregressive conditional heteroscedastic(GARCH) model, estimation of prediction interval based on likelihood is quite sensitive to distribution of error. Moveover, it is not an easy job to construct prediction interval for conditional variance. Recent studies show that the bootstrap method can be one of the alternatives for solving the problems. In this paper, we introduced the bootstrap approach proposed by Pascual et al. (2006). We employed it to Korean stock price data set.

Epidemiology and Trends in Incidence of Kidney Cancer in Iran

  • Mirzaei, Maryam;Pournamdar, Zahra;Salehiniya, Hamid
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.14
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    • pp.5859-5861
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    • 2015
  • Background: Kidney cancer has shown an increasing trend in recent decades. This study aimed to determine change in the incidence rate between 2003 and 2009 in Iran. Materials and Methods: In this study, national cancer registry data were used. Crude incidence rates were calculated per 100,000 and age-standardized incidence rates (ASRs) were computed using the direct standardization method and the world standard population. Significant trend of incidence rates was examined by the Cochran-Armitage test for linear trend. Results: A total of 6,944 cases of kidney cancer were reported. The incidence cases increased from 595 patients in 2003 to 1,387 patients in 2009. Sex ratio (male to female) was 1.67. ASR also increased from 1.18 in 2003 to 2.52 in 2009 per 100,000, but the increasing trend was not significant. Conclusions: A slow increasing trend of incidence rate was observed in the study population. This may be due to an increase of risk factors. It is suggested to perform a study on risk factors for the cancer.

Survival of Colorectal Cancer Patients in the Presence of Competing-Risk

  • Baghestani, Ahmad Reza;Daneshvar, Tahoura;Pourhoseingholi, Mohamad Amin;Asadzade, Hamid
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.15
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    • pp.6253-6255
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    • 2014
  • Background: Colorectal cancer (CRC) is considered to be a main cause of malignancy-related death in the world, being commonly diagnosed in both men and women. It is the third leading cause of cancer dependent death in the world and there are one million new cases diagnosed per year. In Iran the incidence of colorectal cancer has increased during the last 25 years and it is the fifth cause of cancer in men and the third in women. Materials and Methods: In this article we analyzed the survival of 475 colorectal patients of Taleghani hospital in Tehran with the semi-parametric competing-risks model. Results: There were 55% male cases and at the time of the diagnosis most of the patients were between 48 and 67years old. The probability of a patient death from colorectal cancer with survival of more than 25 years was about 0.4. Body mass index, height, tumour site and gender had no influence. Conclusions: According to these data and by using semi-parametric competing-risks method, we found out that only age at diagnosis has a significant effect on these patient survival time.

Epidemiology, Incidence and Mortality of Breast Cancer in Asia

  • Ghoncheh, Mahshid;Mahdavifar, Neda;Darvishi, Efat;Salehiniya, Hamid
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.sup3
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    • pp.47-52
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    • 2016
  • Breast cancer is the most common malignancy in women in Asia and its incidence is rapidly increasing. Information on the incidence and mortality of breast cancer is essential for planning health and more studies. This study aimed to investigate the age-specific incidence and mortality of breast cancer in Asia in 2012. A total of 639,824 cases of breast cancer were recorded in Asian countries, those with the five highest standardized incidence rates being Israel, Lebanon, Armenia, Singapore, and Kazakhstan. The highest number of deaths was observed in India, China, Indonesia, Pakistan, and Japan, respectively. Tith increasing income and improving living standards in developing countries, the incidence of breast cancer increases. This may be due to longer life, higher exposure to risk factors, eating more fatty foods and obesity, and lower pregnancy rates. The variation in incidence rates of breast cancer is very pronounced in Asia (from 80.5 in Israel to 4.6 in Bhuta). A similar situation exists for mortality rates (from 1.8 in Bhutan to 25.2 in Pakistan).

Endometrial Cancer in Hospital Universiti Sains Malaysia

  • Wan-Nor-Asyikeen, Wan Adnan;Siti-Azrin, Ab Hamid;Jalil, Nur Asyilla Che;Othman, Nor Hayati;Zain, Anani Aila Mat
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.6
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    • pp.2867-2870
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    • 2016
  • Background: Endometrial cancer is the most common gynecological malignancy among females worldwide, approximately 320,000 women being diagnosed with the disease each year and 76,000 dying. To date, there is limited knowledge of endometrial cancer in Malaysia. Objectives: To identify the epidemiological profile and prognostic factors of survival. Materials and Methods: A list of endometrial cancer patients in 2000-2011 was obtained from the hospital Record Department. Only cases confirmed by histopathology examination were included. We excluded those with incomplete medical records or referral cases. Simple and multiple Cox regression approaches were used for data analysis. Results: Only 108 cases were included with a mean (SD) age of 62.7 (12.3) years, with 87.0% Malay ethnicity. Grade of cancer was: 29.1% grade 1, 43.7% grade 2 and 27.2% grade 3. The majority of patients had non-endometrioid type (60.2%), with myometrial invasion (82.2%) and lymphovascular invasion (57.3%). The significant prognostic factors were age (HR 1.05; 95% CI: 1.02, 1.08, p=0.002) and having lymphovascular invasion (HR 2.15; 95% CI: 1.08, 4.29; p=0.030). Conclusions: Endometrial cancer patients should be diagnosed earlier to reduce the risk of mortality. The public should be given education on the signs and symptoms of the disease.

Common Genetic Variations in the MUC5AC Gene are Not Related to Helicobacter pylori Serologic Status

  • Zhou, Cheng-Jiang;Zhang, Liu-Wei;Gao, Fang;Zhang, Bin;Wang, Ying;Chen, Da-Fang;Jia, Yan-Bin
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.24
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    • pp.10719-10722
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    • 2015
  • Several lines of evidence suggest that MUC5AC genetic polymorphisms might confer susceptibility to H. pylori infection and therefore gastric cancer risk. We here assessed the association of common polymorphisms in the MUC5AC gene with H. pylori seroprevalence using an LD-based tagSNP approach in a north-western Chinese Han population. A total of 12 tagSNPs were successfully genotyped among 281 unrelated ethnic Han Chinese who had no cancer history, and no identifiable gastric disease or genetic disease. No significant association between any alleles, genotypes or haplotypes and H. pylori seroprevalence was observed. Our results suggest that common genetic variations in MUC5AC gene might not make a major contribution to the risk of H. pylori infection.

Analysis of Interval-censored Survival Data from Crossover Trials with Proportional Hazards Model (교차계획 구간절단 생존자료의 비례위험모형을 이용한 분석)

  • Kim, Eun-Young;Song, Hae-Hiang
    • The Korean Journal of Applied Statistics
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    • v.20 no.1
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    • pp.39-52
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    • 2007
  • Crossover trials of new drugs in the treatment of angina pectoris, which frequently use treadmill exercise test for the assessment of its efficacy, produce censored survival times. In this paper we consider analysis approaches for censored survival times from crossover trials. Previously, a stratified Cox model for paired observation and nonparametric methods have been presented as possible analysis methods. On the other hand, the differences of two survival times would produce interval-censored survival times and we propose a Cox model for interval-censored data as n alternative analysis method. Example data is analyzed in order to compare these different methods.

A New Measure of Agreement to Resolve the Two Paradoxes of Cohen's Kappa (COHEN의 합치도의 두 가지 역설을 해결하기 위한 새로운 합치도의 제안)

  • Park, Mi-Hee;Park, Yong-Gyu
    • The Korean Journal of Applied Statistics
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    • v.20 no.1
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    • pp.117-132
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    • 2007
  • In a $2\times2$ table showing binary agreement between two raters, it is known that Cohen's $\kappa$, a chance-corrected measure of agreement, has two paradoxes. $\kappa$ is substantially sensitive to raters' classification probabilities(marginal probabilities) and does not satisfy conditions as a chance-corrected measure of agreement. However, $\kappa$ and other established measures have a reasonable and similar value when each marginal distribution is close to 0.5. The objectives of this paper are to present a new measure of agreement, H, which resolves paradoxes of $\kappa$ by adjusting unbalanced marginal distributions and to compare the proposed measure with established measures through some examples.

Non-Inferiority Test in a Two-Arm Trial and a Three-Arm Trial Including a Placebo (활성대조군을 이용한 두 군 설계와 위약군을 포함한 세 군 설계의 비열등성 시험)

  • Lee, Ji-Sun;Kim, Dong-Jae
    • The Korean Journal of Applied Statistics
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    • v.21 no.6
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    • pp.947-957
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    • 2008
  • Two-arm non-inferiority trials is often applied to parametric procedure suggested by Hauschke et al. (1999). Since this design does not allow a direct comparison of a new treatment group with placebo group, parametric procedure in a three-arm non-inferiority trial with a placebo group was suggested by Pigeot et al. (2003). But, procedures in these designs are necessary for distribution assumptions. Therefore we propose, in this paper, non parametric procedures employing Wilcoxon rank sum test in a two-arm design and linear contrast test suggested by Scheirer et al. (1976) in a three-arm design. The proposed nonparametric procedures and parametric procedures are compared by Monte Carlo simulation study.