• Title/Summary/Keyword: biostatistics

Search Result 959, Processing Time 0.024 seconds

Comparison of the Performance of Log-logistic Regression and Artificial Neural Networks for Predicting Breast Cancer Relapse

  • Faradmal, Javad;Soltanian, Ali Reza;Roshanaei, Ghodratollah;Khodabakhshi, Reza;Kasaeian, Amir
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.15 no.14
    • /
    • pp.5883-5888
    • /
    • 2014
  • Background: Breast cancer is the most common cancers in female populations. The exact cause is not known, but is most likely to be a combination of genetic and environmental factors. Log-logistic model (LLM) is applied as a statistical method for predicting survival and it influencing factors. In recent decades, artificial neural network (ANN) models have been increasingly applied to predict survival data. The present research was conducted to compare log-logistic regression and artificial neural network models in prediction of breast cancer (BC) survival. Materials and Methods: A historical cohort study was established with 104 patients suffering from BC from 1997 to 2005. To compare the ANN and LLM in our setting, we used the estimated areas under the receiver-operating characteristic (ROC) curve (AUC) and integrated AUC (iAUC). The data were analyzed using R statistical software. Results: The AUC for the first, second and third years after diagnosis are 0.918, 0.780 and 0.800 in ANN, and 0.834, 0.733 and 0.616 in LLM, respectively. The mean AUC for ANN was statistically higher than that of the LLM (0.845 vs. 0.744). Hence, this study showed a significant difference between the performance in terms of prediction by ANN and LLM. Conclusions: This study demonstrated that the ability of prediction with ANN was higher than with the LLM model. Thus, the use of ANN method for prediction of survival in field of breast cancer is suggested.

Hospital-based Study of Endometrial Cancer Survival in Mumbai, India

  • Balasubramaniam, Ganesh;Sushama, S.;Rasika, B.;Mahantshetty, U.
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.14 no.2
    • /
    • pp.977-980
    • /
    • 2013
  • Background: Endometrial cancer is common in western women, and the rates are very high; however in India, the rates are as low as 4.3 per 100,000 (Delhi). Objective: To estimate the survival of endometrial cancer patients based on age, education, family history, tobacco habit, number of pregnancies, clinical extent of disease and treatment received. Materials and Methods: The present retrospective study was carried out at the Tata Memorial Hospital (TMH), Mumbai, India, between 1999-2002. 310 cases treated in TMH were considered as eligible entrants for the study. Five-year survival rates were estimated using actuarial and loss-adjusted (LAR) methods. Results: The proportions of patients dying above 50 years of age, non-residents and illiterates was higher than their counterparts. 54.8% of patients had some form of treatment before attending TMH. There were only 4.2% tobacco-chewers and only 6.1% had a family history of cancer. There were 25.8% who had 3-5 pregnancies (not living children) and 38.1% did not remember the pregnancy history. The 5-year overall survival rate was 92%. The five-year rates indicated better prognosis for those aged less than 50 years (97%), non-tobacco-chewers (94%), with no family history of cancer (93%), with localized disease (93%) and those treated with surgery either alone or as a combination treatment (95%). Conclusions: The present study showed that endometrial cancer patients with localized disease at diagnosis have a good outcome in India. A detailed study will help in understanding the prognostic indicators for survival especially with the newer treatment technologies now available.

Vibration and Ergonomic Exposures Associated With Musculoskeletal Disorders of the Shoulder and Neck

  • Charles, Luenda E.;Ma, Claudia C.;Burchfiel, Cecil M.;Dong, Renguang G.
    • Safety and Health at Work
    • /
    • v.9 no.2
    • /
    • pp.125-132
    • /
    • 2018
  • Background: According to the US Bureau of Labor Statistics, musculoskeletal disorders (MSDs) accounted for 32% of all nonfatal injury and illness cases in 2014 among full-time workers. Our objective was to review and summarize the evidence linking occupational exposures to vibration and awkward posture with MSDs of the shoulder and neck. Methods: A literature search was conducted using the terms musculoskeletal disorders, vibration, and awkward posture. All types of observational epidemiologic studies, with the exception of case reports, published during 1998-2015 were included. Databases searched were MEDLINE (Ovid), Embase (Ovid), Scopus, Ergonomic Abstracts, NIOSHTIC-2, and Health and Safety Science Abstracts. Results: Occupational exposures to whole-body or hand-arm vibration were significantly associated with or resulted in MSDs of the shoulder and neck. Awkward postures while working were also associated with MSDs in these locations. These findings were consistent across study designs, populations, and countries. Conclusion: Occupational exposure to vibration and awkward posture are associated with shoulder and neck MSDs. Longitudinal studies are required to elucidate the mechanisms responsible for these associations, and intervention studies are warranted.

Relationship between the Exposure to Ozone in Seoul and the Childhood Asthma-related Hospital Admissions according to the Socioeconomic Status (사회경제수준에 따른 오존과 소아천식 관련 입원의 상관성 연구)

  • Son, Ji-Young;Kim, Ho;Kim, Sun-Young;Lee, Jong-Tae
    • Journal of Preventive Medicine and Public Health
    • /
    • v.39 no.1
    • /
    • pp.81-86
    • /
    • 2006
  • Background: A number of studies have reported associations between the ambient air pollution concentrations and various health outcomes. Especially, ozone is well known for primary risk factor of asthma attacks. The results of a recent study indicate that the size of the effect on health outcomes due to air pollution varied according to several conditions, including age, gender, race and the socioeconomic status. Therefore, this study was conducted to examine the associations of ozone with the childhood asthma hospitalizations as stratified by the socioeconomic status (SES) at the community level in Seoul, Korea, 2002. Methods: SES at aggregated levels was measured on the basis of average regional health-insurance rate per citizen in the area. We applied the generalized additive model to analyze the effect of ozone on asthma after controlling for the potential confounding variables that were capable of influencing the results. Results: Our analysis showed that the number of children who were hospitalized for asthma increased as the SES of the residence area decreased. The estimated relative risks of hospitalization for asthma, as stratified by the SES of the community level, were 1.12 (95% confidence interval 1.00-1.25) in districts with the highest SES levels, 1.24 (95% CI=1.08-1.43) within the moderate SES levels, and 1.32 (95% CI=1.11-1.58) in the districts with the lowest SES levels. Conclusions: Our analysis showed that exposure to air pollution did not equally affect the health status of individuals. This suggests that not only the biological-sensitivity markers, but also the SES of the subjects should be considered as potentially confounding factors.

Ethnic Variation and Its Association With Malaria Awareness: A Cross-sectional Study in East Nusa Tenggara Province, Indonesia

  • Guntur, Robertus Dole;Kingsley, Jonathan;Islam, Fakir M. Amirul
    • Journal of Preventive Medicine and Public Health
    • /
    • v.55 no.1
    • /
    • pp.68-79
    • /
    • 2022
  • Objectives: This study investigated associations between ethnicity and malaria awareness in East Nusa Tenggara Province (ENTP), Indonesia. Methods: A community-based cross-sectional study was conducted upon 1503 adults recruited by multi-stage cluster random sampling. A malaria awareness questionnaire was used to collect data, according to which participants were classified as aware or unaware of malaria. Logistic regression was applied to quantify the strength of associations of factors with malaria awareness. Results: The participation rate in this study was high (99.5%). The participants were distributed relatively evenly among the Manggarai, Atoni, and Sumba ethnicities (33.0, 32.3, and 30.2%, respectively). Malaria awareness was significantly different amongst these groups; it was most common in the Manggarai ethnicity (65.1%; 95% confidence interval [CI], 59.9 to 70.3) and least common in the Sumba ethnicity (35.0%; 95% CI, 27.6 to 42.4). The most prominent factor influencing the malaria awareness in the Sumba and Manggarai ethnicities was education level, whilst it was socioeconomic status (SES) in the Atoni ethnicity. The likelihood of malaria awareness was significantly higher in adults with an education level of diploma or above (adjusted odds ratio [aOR], 21.4; 95% CI, 3.59 to 127.7 for Manggarai; aOR, 6.94; 95% CI, 1.81 to 26.6 for Sumba). Malaria awareness was significantly more common amongst high-SES adults in the Atoni group (aOR, 24.48; 95% CI, 8.79 to 68.21). Conclusions: Low education levels and low SES were prominent contributors to lower levels of malaria awareness in rural ENTP. Interventions should focus on improving malaria awareness to these groups to support the Indonesian government's national commitment to achieve a malaria elimination zone by 2030.

Statistical Mistakes Commonly Made When Writing Medical Articles (의학 논문 작성 시 발생하는 흔한 통계적 오류)

  • Soyoung Jeon;Juyeon Yang;Hye Sun Lee
    • Journal of the Korean Society of Radiology
    • /
    • v.84 no.4
    • /
    • pp.866-878
    • /
    • 2023
  • Statistical analysis is an essential component of the medical writing process for research-related articles. Although the importance of statistical testing is emphasized, statistical mistakes continue to appear in journal articles. Major statistical mistakes can occur in any of the three different stages of medical writing, including in the design stage, analysis stage, and interpretation stage. In the design stage, mistakes occur if there is a lack of specificity regarding the research hypothesis or data collection and analysis plans. Discrepancies in the analysis stage occur if the purpose of the study and characteristics of the data are not sufficiently considered, or when an inappropriate analytic procedure is followed. After performing the analysis, the results are interpreted, and an article is written. Statistical analysis mistakes can occur if the underlying methods are incorrectly written or if the results are misinterpreted. In this paper, we describe the statistical mistakes that commonly occur in medical research-related articles and provide advice with the aim to help readers reduce, resolve, and avoid these mistakes in the future.

Tea Consumption, Alcohol Drinking and Physical Activity Associations with Breast Cancer Risk among Chinese Females: a Systematic Review and Meta-analysis

  • Gao, Ying;Huang, Yu-Bei;Liu, Xue-Ou;Chen, Chuan;Dai, Hong-Ji;Song, Feng-Ju;Wang, Jing;Chen, Ke-Xin;Wang, Yao-Gang
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.14 no.12
    • /
    • pp.7543-7550
    • /
    • 2013
  • Objective: To evaluate associations between tea consumption, alcohol drinking and physical activity and breast cancer risk among Chinese females. Methods: Three English databases (PubMed, ScienceDirect and Wiley) and three Chinese databases (CNKI, WanFang and VIP) were independently searched by 2 reviewers up to December 2012, complemented by manual searches. The quality of included studies was assessed with the Newcastle-Ottawa Scale items. Random-effects models were used to estimate the pooled odds ratios (ORs) and 95% confidence intervals (CIs). Potential publication bias was estimated through Egger's and Begg's tests. Heterogeneity between studies was evaluated with $I^2$ statistics. Results: Thirty-nine studies involving 13,204 breast cancer cases and 87,248 controls were identified. Compared with non-drinkers, regular tea drinkers had decreased risk (OR=0.79, 95%CIs: 0.65-0.95; $I^2$=84.9%; N=16). An inverse association was also found between regular physical activity and breast cancer risk (OR=0.73, 95%CIs: 0.63-0.85; $I^2$=77.3%; N=15). However, there was no significant association between alcohol drinking and breast cancer risk (OR=0.85, 95%CIs: 0.72-1.02; $I^2$=63.8%; N=26). Most of the results from the subgroup analysis were consistent with the main results. Conclusion: Tea consumption and physical activity are significantly associated with a decreased risk of breast cancer in Chinese females. However, alcohol drinking may not be associated with any elevation of risk.

Associations of Depressive Symptoms and Brachial Artery Reactivity among Police Officers

  • Violanti, John M.;Charles, Luenda E.;Gu, Ja K.;Burchfiel, Cecil M.;Andrew, Michael E.;Joseph, Parveen N.;Dorn, Joan M.
    • Safety and Health at Work
    • /
    • v.4 no.1
    • /
    • pp.27-36
    • /
    • 2013
  • Objectives: Mental health has been shown to be linked with certain underlying physiological mechanisms. The objective of this cross sectional study was to investigate the relationship between depressive symptoms and brachial artery reactivity (BAR) in an understudied population: police officers. Methods: Participants were 351 police officers who were clinically examined in the Buffalo Cardio-Metabolic Police Stress (BCOPS) study. BAR was performed using standard B-Mode ultrasound procedures. Depressive symptoms were measured using the Center for Epidemiological Studies Depression (CES-D) scale. Mean values of the difference between the baseline and maximum diameters of the brachial artery were determined across three categories of CES-D score using the analysis of variance and the analysis of covariance. p-values for linear trends were obtained from linear regression models. Results: The mean age (${\pm}$ standard deviation) of all officers was $40.9{\pm}7.2$ years. Women had a slightly higher mean CES-D score than men ($8.9{\pm}8.9$ vs. $7.4{\pm}6.4$) and a slightly higher percentage increase of BAR than men (6.90 vs. 5.26%). Smoking status significantly modified the associations between depressive symptoms and BAR. Among current smokers, mean absolute values of BAR significantly decreased as depressive symptoms increased after adjustment for age, gender, race/ethnicity, hypertension, and diabetes; the multivariate-adjusted p-values were 0.033 (absolute) and 0.040 (%). Associations between depressive symptoms and BAR were not statistically significant among former smokers or never smokers. Conclusion: Depressive symptoms were inversely associated with BAR among police officers who were current smokers and together may be considered a risk factor for cardiovascular disease among police officers. Further prospective research is warranted.

Incidence and Mortality of Bladder Cancer and their Relationship with Development in Asia

  • Pakzad, Reza;Mohammadian-Hafshejani, Abdollah;Mohammadian, Mahdi;Pakzad, Iraj;Safiri, Saeid;Khazaei, Salman;Salehiniya, Hamid
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.16 no.16
    • /
    • pp.7365-7374
    • /
    • 2015
  • Background: Over the past decade, bladder cancer was associated with a significant increase. Given the importance of the impact of socioeconomic status on the distribution of cancer incidence and mortality, and the need to information on these parameters for prevention planning, the aim of this study was to evaluate data for bladder cancer and their relationship with human development index (HDI) and its components in Asia in 2012. Materials and Methods: The study was conducted based on data from the world data of cancer and the World Bank (including the HDI and its components). The incidence and mortality rates were drawn for Asian countries. To analyze data, correlation tests between incidence and death rates, and HDI and its components were employed with a significance level of 0.05 using SPSS software. Results: A total incidence of 696,231 cases (68.7% in males and 31.3% in females, sex ratio of 2.19:1) and 524,465 deaths (67.0% in men and 32.9% in women, sex ratio was 2.03:1) were recorded in Asian countries in 2012. Correlation between HDI and standardized incidence rate was 0.241 overall (p=0.106), 0.236 in men (p=0.114) and -0.250 in women (p=0.094). Also between HDI and standardized mortality rate 0.025 (p=0.871) in men 0.118 (p=0.903) and in women 0.014 (p=0.927). Conclusions: Bladder cancer incidence is higher in developed countries, but the rate is declining, and in less developed and developing countries it is growing. There was no statistically significant correlation between the standardized incidence rate of bladder cancer and the HDI and its dimensions in Asia, except for the level of education.

Statistical Estimates from Black Non-Hispanic Female Breast Cancer Data

  • Khan, Hafiz Mohammad Rafiqullah;Ibrahimou, Boubakari;Saxena, Anshul;Gabbidon, Kemesha;Abdool-Ghany, Faheema;Ramamoorthy, Venkataraghavan;Ullah, Duff;Stewart, Tiffanie Shauna-Jeanne
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.15 no.19
    • /
    • pp.8371-8376
    • /
    • 2014
  • Background: The use of statistical methods has become an imperative tool in breast cancer survival data analysis. The purpose of this study was to develop the best statistical probability model using the Bayesian method to predict future survival times for the black non-Hispanic female breast cancer patients diagnosed during 1973-2009 in the U.S. Materials and Methods: We used a stratified random sample of black non-Hispanic female breast cancer patient data from the Surveillance Epidemiology and End Results (SEER) database. Survival analysis was performed using Kaplan-Meier and Cox proportional regression methods. Four advanced types of statistical models, Exponentiated Exponential (EE), Beta Generalized Exponential (BGE), Exponentiated Weibull (EW), and Beta Inverse Weibull (BIW) were utilized for data analysis. The statistical model building criteria, Akaike Information Criteria (AIC), Bayesian Information Criteria (BIC), and Deviance Information Criteria (DIC) were used to measure the goodness of fit tests. Furthermore, we used the Bayesian approach to obtain the predictive survival inferences from the best-fit data based on the exponentiated Weibull model. Results: We identified the highest number of black non-Hispanic female breast cancer patients in Michigan and the lowest in Hawaii. The mean (SD), of age at diagnosis (years) was 58.3 (14.43). The mean (SD), of survival time (months) for black non-Hispanic females was 66.8 (30.20). Non-Hispanic blacks had a significantly increased risk of death compared to Black Hispanics (Hazard ratio: 1.96, 95%CI: 1.51-2.54). Compared to other statistical probability models, we found that the exponentiated Weibull model better fits for the survival times. By making use of the Bayesian method predictive inferences for future survival times were obtained. Conclusions: These findings will be of great significance in determining appropriate treatment plans and health-care cost allocation. Furthermore, the same approach should contribute to build future predictive models for any health related diseases.