Journal of Biostatistics and Epidemiology

Longitudinal Data Clustering Methods: A Systematic ReviewLongitudinal Data Clustering Methods: A Systematic Review

Arefeh Dehghani Tafti — 2024-10-13

Introduction: In the last few decades, in many research fields, different methods were introduced to discover groups with the same trends in longitudinal data. The clustering process is an unsupervised learning method, which classifies longitudinal data based on different criteria by performing algorithms. The current study was performed with the aim of reviewing various methods of longitudinal data clustering, including two general categories of non-parametric methods and model-based methods.

Methods: In this research, to obtain related scientific articles, PubMed, Science Direct Scopus, ISI, and Google Scholar were searched between 2000 and 2021.

Results: According to our systematic review, the non-parametric k-means Clustering Method utilizing Euclidean distance emerges as a leading approach for clustering longitudinal data.

Conclusion: This research, with an overview of the studies done in the field of clustering, can help researchers as a toolbox to choose various methods of longitudinal data clustering in idea generation and choosing the appropriate method in the classification and analysis of longitudinal data.

Studying the Relationship between the Teaching Status of Research Methods, Biostatistics Courses and, Academic Research Skills, from the Graduates Point of View

Fatemeh Sadat Hosseini-Baharanchi — 2024-10-13

Introduction: This study aimed to evaluate the relationship between passing biostatistics and research methods courses and academic research skills in graduates.

Methods: This cross-sectional study included 633 graduates during 2016-2022 from Iran University of Medical Sciences, Tehran, Iran. The explanatory factors were passing biostatistics and research methods courses and having statistical consultant. The outcomes were the duration of preparing proposal and thesis, and paper publication. Univariate and multiple logistic regression was used to estimate the odds ratio (OR) with %95CI. Significance level was set to 0.05

Results: 433 (68.4%) were female, and 371 (58.6%) were married. The mean±SD age of the graduates was 34.5±7.06 years. 413 (65.2%) were graduates from MSc and MPH and 128 (20.2%) from PhD. For Masters and MPH, the odds of prolonging the duration of preparing the proposal for who had Biostatistical consultant in their research team was 40% lower than the graduates who had no Biostatistical consultant (OR=0.6[95%CI:(0.39,0.91], P=0.01). In PhD graduates, the odds of prolonging the duration of preparing the proposal for who passed research methods course was 2.94 (1.06, 8.2) times than that of did not pass (P=0.03). Passing Biostatistics course was associated with lower odds of prolonging the duration of preparing thesis (OR=0.3[95% CI: (0.1, 0.86)], P=0.04). The odds of paper publication was marginally associated with research methods workshop participation (OR=3.7[95%CI: (0.82, 16.74], P=0.09) in PhD graduates.

Conclusion: Passing Biostatistics and research methods courses and presence of a statistical consultant in the students’ thesis team were associated with shortened proposal or thesis preparation duration, and having publications from thesis more likely.

CRP, PCT, and D-dimer as Biomarkers for Disease Severity in COVID-19 Patients: A Retrospective Study in Kinshasa, Democratic Republic of Congo

Tasnime Hamdeni — 2024-10-13

Introduction: The COVID-19 pandemic has had a significant impact on global health, resulting in more than 6 million reported deaths worldwide as of April 2023. This study aimed to investigate the potential of C-reactive protein (CRP), procalcitonin (PCT), and D-dimer as biomarkers for assessing disease severity in COVID-19 patients in Kinshasa, Democratic Republic of Congo

Methods:A retrospective examination was conducted involving 339 COVID-19 patients admitted to Kinshasa hospitals between January 2021 and March 2022. CRP, PCT, and D-dimer levels were measured in all patients and compared between those with severe and non-severe illnesses.

Results: Our findings revealed significantly higher CRP, PCT, and D-dimer levels in severe cases compared to non-severe cases. Specifically, the median CRP level was 120.6 mg/L in severe cases, 47.3 mg/L in mild cases, and 13.5 mg/L in moderate cases. The median PCT levels were 0.26 ng/mL in severe cases, 0.08 ng/ mL in mild cases, and 0.07 ng/L in moderate cases. Additionally, the median D-dimer level was 1836.9 µg/L in severe cases and 597.6 µg/L in mild cases, with a value of 481.1 µg/L in moderate cases. System learning techniques were also employed to predict disease severity based on these biomarkers, achieving high accuracy.

Conclusion: Our findings suggest that CRP, PCT, and D-dimer serve as valuable biomarkers for identifying severe COVID-19 cases in Kinshasa. Furthermore, the application of machine learning methods can yield accurate predictions of disease severity based on these biomarkers. These biomarkers hold the potential to assist clinicians in informed decision-making regarding patient management and contribute to improved clinical outcomes for COVID-19 patients.

Associations between Conspiracy Ideation, Covid-19 Conspiracy Ideation with Adherence to Preventive Measures among Adults in Kuwait: A Cross-Sectional Study

Nourah K. Alajmi — 2024-10-13

Introduction: A lack of knowledge about COVID-19 has led people to believe in conspiracy theories, their origins, and their purposes. These theories influence people’s compliance with preventive strategies and accepting vaccination, thus affecting the overall community health. This study investigated the association between compliance with preventive measures, conspiracy ideation, and COVID-19 conspiracy ideation.

Methods:Data from 554 participants ≥18 years were collected using a questionnaire distributed over social media platforms. Associations between compliance with preventive strategies and several covariates were investigated. To quantify/test the effect of belief in conspiracy theory and COVID-19 conspiracy while accounting for other covariates, a multiple logistic regression model was implemented to estimate odds ratios (OR) and their 95% confidence intervals (CI).

Results: Participants were mainly males (58.3%), employed (61.2%), and Kuwaiti nationals (79.1%) with a median (IQR) age of 32 (20) years. The prevalence of generic conspiracy ideation, COVID-19 conspiracy, and poor compliance with preventive measures were 33%, 28.3%, and 34.7%, respectively. After adjustment for several covariates, believers in conspiracy theory (aOR=1.97, 95%CI:1.24-3.14), believers in COVID-19 conspiracy (aOR=1.96, 95%CI:1.2– 3.21), compared to none/low believers, were significantly associated with poor compliance with preventive measures.

Conclusion: Believers in conspiracy theories and COVID-19 conspiracy theories are significantly more likely to be poorly compliant with preventive measures against COVID-19. This has a negative effect on the community health. Policymakers need to address conspiracy theories on public platforms which will help promote the adaptation of correct public health practices and preventive strategies leading to better health of the community.

A New Lifetime Distribution and its Application to Cancer Data

Samuel Adewale Aderoju — 2024-10-13

Introduction: Recently, researchers have introduced new generated families of univariate lifetime distributions. These new generators are obtained by adding one or more extra shape parameters to the underlying distribution or compounding two distributions to get more flexibility in fitting data in different areas such as medical sciences, environmental sciences, and engineering. The addition of parameter(s) has been proven useful in exploring tail properties and for improving the goodness-of-fit of the family of the proposed distributions.

Methods:A new Three-Parameter Weibull-Generalized Gamma distribution which provides more flexibility in modeling lifetime data is developed using a two-component mixture of Weibull distribution (with parameters θ and λ) and Generalised Gamma distribution (with parameters α=4,θ and λ). Some of its mathematical properties such as the density function, cumulative distribution function, survival function, hazard rate function, moment generating function, Renyi entropy and order statistics are obtained. The maximum likelihood estimation method was used in estimating the parameters of the proposed distribution and a simulation study is performed to examine the performance of the maximum likelihood estimators of the parameters.

Results: Real life applications of the proposed distribution to two cancer datasets are presented and its fit was compared with the fit attained by some existing lifetime distributions to show how the Three-Parameter Weibull-Generalized Gamma distribution works in practice

Conclusion: The results suggest that the proposed model performed better than its competitors and it’s a useful alternative to the existing models.

Using Network Analysis to Examine the Brain Regions Connectivity of Functional Neurological Disorder Patient and Healthy Participant

Samira Ahmadi — 2024-10-13

Introduction: Functional neurological disorder (FND) is one of the most common causes of neuropathy, However, its cause continues to be mysterious. Understanding the underlying mechanisms of that is crucial for treatment strategies. The study was conducted on brain images resting state fMRI taken from two volunteers (functional neurological disorder patient and healthy subject)who had the same characteristics.

Methods: We fitted Gaussian Graphical Models to a single subject data using a network approach.

Results: Based on the results of the networks, the number of significant edges was more in the left hemisphere in the patient, but in the healthy person, the number of these non-zero edges was more in the right hemisphere. Both the networks related to the healthy person and the patient had high density. Therefore, it indicated that the regions considered by these 2 people were strongly related to each other. The results showed the existence of more links and positive relationships between the regions, most of which showed a strong relationship. Among these connections, there were also negative connections. The networks of the healthy participant with almost symmetrical structures and the patient with Functional neurological disorder showed different characteristics, including asymmetry between the hemispheres.

Conclusion: this study is the first to demonstrate that the brain regions of both functional neurological disorder patient and healthy participant can be conceptualized as networks. The findings of this study add to a growing body of literature that functional neurological disorder patient brain regions can be analyzed using network approaches.

Sample Size Calculation Based on Research Approaches in Animal Studies

Alireza Pakgohar — 2024-10-13

Introduction: Sample sizes that are too small can produce inconclusive results, while sample sizes that are too large may raise ethical concerns and produce trivial outcomes. Ethical considerations of sample size calculation in animal studies are essential and researchers should consider the 3R approach. Therefore, accurately calculating the sample size is essential to ensure adequate statistical power and avoid wastage of resources.

Methods: The paper presents several innovative approaches for conducting small-scale sampling in animal studies. It includes a comprehensive review of relevant literature, discussing various proposed methods for determining sample size in animal studies

Results: In this study, various formulas are available for preparing sample size calculations that are relevant to the research design. These include t-tests (for one sample and two independent/paired samples), ANOVA, ANCOVA, simple/multiple linear regression, as well as proportion studies and studies utilizing correlation coefficients

Conclusion: Our aims to equip researchers with formulas for reliable findings and adherence to ethical principles for sample size calculating in animal studies.

On The Modeling of Biomedical Data Sets with a New Generalized Exponentiated Exponential Distribution

Ismail Adekunle KolawoleKolawole — 2024-10-13

Introduction: Many experts in the field of distribution theory have focused on extending probability distributions utilizing extended families of continuous distributions to improve the modeling adaptability of the conventional probability distributions.

Methods: This research employed a continuous family of probability distributions as introduced in the literature using the T-X methodology. Through this, some of statistical and mathematical properties of the model were derived and studied

Results: This study had introduced a brand-new, five-parameter generalized exponentiated exponential distribution, which is a continuous probability distribution. With the aid of the quantile function, moments, moment generating function, survival function, hazard function, mean, and median, among other mathematical and statistical aspects, the new distribution's shape was deduced and researched. It was also possible to derive the probability density function for the minimum and maximum order statistics for this distribution. The method of maximum likelihood estimate was used to produce a conventional estimation of the unknown parameters. A simulation study was carried out to assess the efficiency and consistency of the estimation method used. To evaluate the fit and adaptability of the new model, it was applied to four real-world datasets in the field of medicine.

Conclusion: The analysis's findings demonstrated that the new model performs better than its counterparts and offers a better fit than the Topp-Leone exponentiated exponential, Topp-Leone Kumaraswamy exponential, exponentiated exponential, and exponential distributions.

Socio-Economic Status of Individuals in Tehran University of Medical Sciences Employees` Cohort Study Using PCA, MCA and FAMD Methods

Faezeh Ramezanzadeh Tabriz — 2024-10-13

Introduction: Determining socio-economic status (SES) can greatly help decision makers in the field of social health. Because SES can play an important role in accessing medical services or welfare amenities. We aimed to determine the SES using principal component analysis (PCA), multiple correspondence analysis (MCA), and factor analysis of mixed data (FAMD) methods.

Methods: In this cross-sectional study (2023), 4448 employees aged 19 to 75 years were included to the study from Tehran University of Medical Sciences employees` cohort (TEC). Demographic variables and socioeconomic factors were considered. Considering the weaknesses of PCA and MCA methods, we calculated the SES score using PCA, MCA and FAMD methods, and the percentile of people was determined. These weaknesses include normality assumption and considering only linear relationship for PCA, inability to interpret the relationships between variables and considering each level of classification variables as a new variable for MCA.

Results: We studied 4448 people (39.3% men) with mean age of 42.3 and a standard deviation of 8.7.The correlation between the percentiles obtained through PCA, MCA and FAMD methods was very high, and the highest correlation was related to the percentiles obtained through PCA and FAMD methods with a value of 0.994. The intraclass correlation coefficient value was 0.996. Also, this value was 0.996 and 0.994 in the random samples of 250 and 100 individuals from the original data, respectively.

Conclusion: All of the three methods worked similarly on determining the SES and calculating the percentile of people. PCA and FAMD methods had better agreement than others. Therefore, in studies that have both quantitative and qualitative variables, the choice of analysis method depends on the opinion of the researcher.