Multivariate Analysis: The Need for Data, and other Problems

1975 ◽  
Vol 126 (3) ◽  
pp. 237-240 ◽  
Author(s):  
B. S. Everitt
Keyword(s):  
Multivariate Analysis ◽  
Statistical Methods ◽  
Multivariate Analyses ◽  
Careful Consideration ◽  
Initial Screening ◽  
Journal Editors ◽  
Variable Distribution ◽  
Significance Levels ◽  
Type Variable ◽  
Size Variable

SummaryMultivariate analyses are an aid to, not a substitute for critical thinking in the area of data analysis. Meaningful results can only be produced by these methods if careful consideration is given to questions of sample size, variable type, variable distribution etc., and accusations of subjectivity in interpretation can only be overcome by replication.The computer revolution has produced many problems for statisticians, not least of which is the ease with which experimenters may access packages of programs for multivariate analysis, and so bypass a ‘difficult’ (by which is meant one who will not do simply as he is told) statistician. Of course there are many abuses of univariate statistical methods. Here, however, the abuses are not likely to lead to such seriously misleading results as in the multivariate case.Perhaps a major cause of the continuing misuse of statistical methods is the insistence of many journal editors in psychology and related areas, on articles being laced with multivariate analyses, and on encouraging the pedantic use of significance levels, i.e. the inevitable p < —, as if such inclusions lent an air of respectability to their journal which it might not otherwise have had. Research workers in these fields would be better encouraged to devote more time to an initial screening of their data using simple graphical techniques, to ensure that their data are at least approximately suitable for more complicated multivariate analyses.

scholarly journals Prediction of Outcome for Transabdominal Cerclage in Women with Cervical Insufficiency

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Ji Eun Song ◽  
Keun Young Lee ◽  
Ga Hyun Son
Keyword(s):  
Risk Factors ◽  
Multivariate Analysis ◽  
Cohort Study ◽  
Pregnancy Outcomes ◽  
Retrospective Cohort ◽  
Multivariate Analyses ◽  
Univariate Analysis ◽  
Cervical Length ◽  
Cervical Insufficiency ◽  
Prediction Of Outcome

We investigated pregnancy outcome following transabdominal cerclage (TAC) in women with cervical insufficiency (CI) and explored parameters for predicting pregnancy outcomes following TAC. In this retrospective cohort study, we included 161 women with TAC. We considered demographic, obstetric, and gynecologic histories, pre- and postoperative cervical length (CL), and CL at 20–24 weeks as parameters for predicting outcomes following TAC. Univariate and multivariate analyses were used to identify risk factors for predicting delivery before 34 weeks after TAC. 182 pregnancies occurred after TAC, and 290 pregnancies prior to TAC were identified. The rate of delivery <34 weeks significantly decreased following TAC (5% versus 82%,P<0.001). Univariate analysis demonstrated that a short CL (<25 mm) at 20–24 weeks and adenomyosis were associated with delivery at <34 weeks’ gestation following TAC (P=0.015andP=0.005, resp.). However, multivariate analysis demonstrated that only a short CL (<25 mm) at 20–24 weeks was a significant predictor (P=0.005). TAC is an efficacious procedure that prolongs pregnancy in women with CI. A short CL at 20–24 weeks may predict the delivery at <34 weeks’ gestation following TAC.

scholarly journals Guidelines for performing Mendelian randomization investigations

2020 ◽  
Vol 4 ◽  
pp. 186 ◽  
Author(s):  
Stephen Burgess ◽  
George Davey Smith ◽  
Neil M. Davies ◽  
Frank Dudbridge ◽  
Dipender Gill ◽  
...  
Keyword(s):  
Statistical Methods ◽  
Genetic Variants ◽  
Mendelian Randomization ◽  
Data Sources ◽  
Sensitivity Analyses ◽  
Primary Analysis ◽  
Data Presentation ◽  
Journal Editors ◽  
Robust Statistical Methods

This paper provides guidelines for performing Mendelian randomization investigations. It is aimed at practitioners seeking to undertake analyses and write up their findings, and at journal editors and reviewers seeking to assess Mendelian randomization manuscripts. The guidelines are divided into nine sections: motivation and scope, data sources, choice of genetic variants, variant harmonization, primary analysis, supplementary and sensitivity analyses (one section on robust statistical methods and one on other approaches), data presentation, and interpretation. These guidelines will be updated based on feedback from the community and advances in the field. Updates will be made periodically as needed, and at least every 18 months.

An Inconvenient Truth: Arbitrary Distinctions Between Organizational, Mechanical Turk, and Other Convenience Samples

2015 ◽  
Vol 8 (2) ◽  
pp. 142-164 ◽  
Author(s):  
Richard N. Landers ◽  
Tara S. Behrend
Keyword(s):  
Social Sciences ◽  
Research Question ◽  
Sampling Strategy ◽  
Careful Consideration ◽  
Omitted Variables ◽  
Range Restriction ◽  
Convenience Sample ◽  
Journal Editors ◽  
An Inconvenient Truth ◽  
Methods Textbooks

Sampling strategy has critical implications for the validity of a researcher's conclusions. Despite this, sampling is frequently neglected in research methods textbooks, during the research design process, and in the reporting of our journals. The lack of guidance on this issue often leads reviewers and journal editors to rely on simple rules of thumb, myth, and tradition for judgments about sampling, which promotes the unnecessary and counterproductive characterization of sampling strategies as universally “good” or “bad.” Such oversimplification, especially by journal editors and reviewers, slows the progress of the social sciences by considering legitimate data sources to be categorically unacceptable. Instead, we argue that sampling is better understood in methodological terms of range restriction and omitted variables bias. This considered approach has far-reaching implications because in industrial–organizational (I-O) psychology, as in most social sciences, virtually all of the samples are convenience samples. Organizational samples are not gold standard research sources; instead, they are merely a specific type of convenience sample with their own positive and negative implications for validity. This fact does not condemn the science of I-O psychology but does highlight the need for more careful consideration of how and when a finding may generalize based on the particular mix of validity-related affordances provided by each sample source that might be used to investigate a particular research question. We call for researchers to explore such considerations cautiously and explicitly both in the publication and in the review of research.

Increase in MEG3, MALAT1, NEAT1 significantly predicts the clinical parameters in patients with rheumatoid arthritis

2020 ◽  
Vol 17 (6) ◽  
pp. 445-457
Author(s):  
Sudipta Chatterjee ◽  
Dipanjan Bhattcharjee ◽  
Sanchaita Misra ◽  
Ayindrila Saha ◽  
Nitai Pada Bhattacharyya ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
Multivariate Analysis ◽  
Synovial Fluid ◽  
Disease Activity ◽  
Peripheral Blood ◽  
Multivariate Analyses ◽  
Clinical Parameters

Aim: This study investigated deregulation of lncRNAs MEG3, MALAT1, NEAT1 and their associations with clinical parameters in rheumatoid arthritis (RA). Materials & methods: LncRNAs MALAT1, MEG3, NEAT1 were quantified from peripheral blood mono-nuclear cells (PBMCs) and plasma of 82 RA patients with 15 matched controls and from knee fluid of 24 RA patients with ten osteoarthritis controls. Multivariate analyses were performed among lncRNAs and clinical parameters of RA. Results: MALAT1, MEG3, NEAT1 were increased in PBMCs, plasma, synovial fluid (p < 0.05) of RA patients. Significant correlations were observed for MEG3 with TJC (r = 0.29), NEAT1 with TJC (r = 0.49), swollen joint count (r = 0.20), DAS28-CRP (r = 0.29). Multivariate analysis revealed that 48.5% of TJC and 31.5% of swollen joint count could be predicted by lncRNAs. Conclusion: The findings suggested that the lncRNAs might be explored as probable markers in monitoring disease activity.

Assessment of gminas’ socio-economic development in the Mazowieckie Voivodship using methods of multivariate analysis

2016 ◽  
Vol 61 (6) ◽  
pp. 59-69 ◽  
Author(s):  
Mariola Chrzanowska ◽  
Nina Drejerska
Keyword(s):  
Economic Development ◽  
Multivariate Analysis ◽  
Data Analysis ◽  
Comparative Analysis ◽  
Statistical Methods ◽  
Local Development ◽  
Relative Level ◽  
Development Level ◽  
Socio Economic Development ◽  
Quantitative Characteristics

Statistical methods for comparing objects allow them to study taking into account several features simultaneously, thereby increasing the efficiency of testing. It can be concluded that the methods of multidimensional comparative data analysis can provide specific research instruments of local development. The article presents the proposal to apply to study the level of development of gminas in the Mazowieckie Voivodship two methods of multidimensional comparative analysis, ie. indicator of the relative level of development as well as a synthetic measure which takes into account the zero unitarisation method. The assessment of the development level of gminas was carried out using quantitative characteristics based on data from the official statistics for the years 2007 and 2013.

Structural discrimination of nanosilica particles and mixed-structure silica by multivariate analysis applied to SAXS profiles in combination with FT-IR spectroscopy

RSC Advances ◽  
2016 ◽  
Vol 6 (76) ◽  
pp. 72306-72316 ◽  
Author(s):  
Y. P. Ruiz ◽  
M. F. Ferrão ◽  
M. B. Cardoso ◽  
E. A. Moncada ◽  
J. H. Z. dos Santos
Keyword(s):  
Multivariate Analysis ◽  
Ir Spectroscopy ◽  
Mesoporous Silica ◽  
Multivariate Analyses ◽  
Mixed Structure ◽  
Silica Materials ◽  
Ft Ir ◽  
Mesoporous Silica Materials ◽  
Nanosilica Particles ◽  
Ft Ir Spectroscopy

New methodology to quickly identify changes in the structural properties of mesoporous silica materials through simultaneous multivariate analyses applied to techniques with different principles as SAXS curves and FT-IR spectra.

Acquisition of Methicillin-Resistant Staphylococcus aureus in a Large Intensive Care Unit

2003 ◽  
Vol 24 (5) ◽  
pp. 322-326 ◽  
Author(s):  
Caroline Marshall ◽  
Glenys Harrington ◽  
Rory Wolfe ◽  
Christopher K. Fairley ◽  
Steve Wesselingh ◽  
...  
Keyword(s):  
Multivariate Analysis ◽  
Length Of Stay ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Multivariate Analyses ◽  
University Hospital ◽  
Trauma Patients ◽  
Increased Risk ◽  
Risk Patients ◽  
Mrsa Colonization ◽  
Previous Admission

AbstractObjectives:To determine the prevalence of MRSA colonization on admission to the ICU and the incidence of MRSA colonization in the ICU.Design:Prospective cohort study.Setting:University hospital.Participants:Patients admitted to the ICU in 2000-2001.Methods:Patients were screened for MRSA with nose, throat, groin, and axilla swabs on admission and discharge. MRSA acquisition was defined as a negative admission screen and a positive discharge screen. Risk factors analyzed included previous wards/current unit, gender, age, and length of stay prior to and in the ICU. Univariate and multivariate analyses were performed using logistic regression.Results:Of screened patients, 6.8% were MRSA colonized on admission to the ICU. Some patients (11.4%) became newly colonized during their stay in the ICU. Factors that remained significant in the multivariate analysis of MRSA colonization on admission were previous admission to various wards and length of stay prior to ICU admission of more than 3 days. In the multivariate analysis of MRSA acquisition in the ICU, being a trauma patient and length of stay in the ICU greater than 2 days remained significant. Thirty-six percent of patients had both admission and discharge swabs taken. This percentage increased in the presence of a supervisory nurse.Conclusion:Significant acquisition of MRSA occurs in the ICU of our hospital, with trauma patients at increased risk. Patients who had been on the cardiothoracic ward prior to the ICU had a lower risk of MRSA colonization on admission. Presence of a supervisory nurse improved compliance with screening.

scholarly journals DETERMINATION OF PLACES OF ADMISSION OF MEDICAL CARE DEFECTS

2019 ◽  
Vol 5 (1) ◽  
pp. 29-32
Author(s):  
Z. A. Giyasov ◽  
Sh. E. Islamov
Keyword(s):  
Multivariate Analysis ◽  
Medical Care ◽  
Statistical Methods ◽  
Emergency Medical Care ◽  
Medical Specialties ◽  
Forensic Institutions ◽  
The Republic ◽  
Medical Examinations ◽  
Regional Hospitals

The article is devoted to determination of places of admission of medical care defects. The purpose of the study was to determine the defects of medical care in the context of institutions, among specialists in various fields, by the nature and causes of occurrence. The material of the study was the findings of the commission of forensic medical examinations about professional offenses of medical workers conducted in all forensic institutions of the Republic of Uzbekistan. With a comprehensive multivariate analysis of the data obtained, logical, dialectical, comparative methods were used, as well as the collection and study of individual facts, monographic descriptions and statistical methods. It was revealed that medical care defects were mostly committed at the stage of hospitalization in central regional hospitals, emergency medical care units and at the stage before hospitalization in rural medical aid stations and polyclinics. Among medical specialties the defects were more often revealed in the work of obstetricians-gynecologists, surgeons, pediatrists, etc. The defects in diagnosis and treatment were prevailing and they developed due to subjective causes. The data concerning medical localizations were the defects were committed, taking into consideration specialties, essence and causes of development, were presented.

Association of RAS mutations with race in metastatic colorectal cancer: CALGB/SWOG 80405 (ALLIANCE).

2018 ◽  
Vol 36 (4_suppl) ◽  
pp. 638-638 ◽  
Author(s):  
Amikar Sehdev ◽  
Donna Niedzwiecki ◽  
Alan P. Venook ◽  
Heinz-Josef Lenz ◽  
Federico Innocenti ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Multivariate Analysis ◽  
Adjuvant Chemotherapy ◽  
Multivariate Analyses ◽  
Exon 2 ◽  
Ras Mutation ◽  
Pelvic Radiation ◽  
Ras Mutations ◽  
Mutational Status ◽  
Significant Difference

638 Background: Colorectal cancer (CRC) is a heterogeneous disease with distinct molecular subtypes in part based on RAS mutational status. It is plausible that RAS mutations are differentially distributed between CC and AA and may contribute to poor outcomes in AAs with CRC. Methods: We did a retrospective analysis of CALGB/SWOG 80405 trial patients. We divided the entire cohort into 2 groups: a) Common RAS: mutation in KRAS exon 2, codon 12 or 13; b) Extended RAS: any NRAS mutations or mutation in KRAS except those listed above. We then analyzed these two subgroups for association between RAS mutations and race (3 categories: Caucasian, AA, Others) using chi-square test for univariate analyses and logistic regression for multivariate analysis. We also analyzed the effect of extended RAS testing on prognosis of metastatic CRC by estimating the overall survival (OS) using Kaplan-Meier method and 95% confidence interval (CI). Cox proportional-hazard model was used for multivariate analyses. Results: There were 1729 CRC patients in common RAS group of which 357 (20.6%) had mutations present. Extended RAS group had 621 patients of which 95 (15.5%) had mutations present. There was no significant difference in the rate of common RAS mutations between CC and AA (20.5% vs. 24%, p=0.22). However, extended RAS mutations were significantly more in AA as compared to CC (25% vs. 14%, p=0.02). Multivariate analysis adjusted for age, gender, prior adjuvant chemotherapy and pelvic radiation confirmed higher odds of extended RAS mutation in AA compared to CC (adjusted OR 1.12; 95% CI 1.01-1.23; p=0.02). The median OS in patients with an extended RAS mutation was shorter as compared to those without extended RAS mutation (25.3 vs. 31.9 months; HR 1.26; 95% CI 0.99-1.62; p=0.05). Multivariate analyses adjusted for age, gender, race, prior adjuvant chemotherapy and pelvic radiation showed a trend towards longer OS in patients without extended RAS mutation as compared those with extended RAS mutation (adjusted HR= 1.24, 95% CI, 0.97-0.1.58, p=0.08). Conclusions: Extended RAS mutations are significantly more common in AA as compared to CC. Additionally, presence of extended RAS mutation may confer a poor prognosis in CRC patients.

MULTIVARIATE ANALYSES OF POTATO HYBRIDS. II. DISCRIMINATION BETWEEN TUBEROSUM-ANDIGENA HYBRID FAMILIES AND THEIR RELATIONSHIP TO THEIR PARENTS

1980 ◽  
Vol 22 (2) ◽  
pp. 279-286 ◽  
Author(s):  
G. C. C. Tai ◽  
T. R. Tarn
Keyword(s):  
Multivariate Analysis ◽  
Multivariate Analyses ◽  
Yield Traits ◽  
Additive Effects ◽  
Breeding Strategies ◽  
Two Dimensional ◽  
Long Day ◽  
Canonical Variates ◽  
The Mean ◽  
Hill Plots

In 1978 17 families from crosses between Tuberosum and long-day adapted Andigena parents were compared with each other and their parents using ten-hill plots. The mean performance of all Tuberosum-Andigena hybrid families was between the performances of the parental groups for six of eight traits, while in the best families the means of some yield traits exceeded the best parent. Multivariate analysis of seven traits gave five significant canonical variates which accounted for 96.6% of the variation. Two dimensional canonical diagrams showed a considerable overlap of the hybrid families and the Andigena parents, but very little overlap of either of these with the Tuberosum parents. Canonical distances between the hybrid families and the parents showed the families to be closer to the mid-parent value than to either parent, and closer to the Andigena parent than to the Tuberosum parent. The results suggest that the genetic effects of the Andigena parents are stronger than those of the Tuberosum parents, while non-additive effects are also important. Only the better Andigena parents and hybrid families are close to or overlap the distribution of the Tuberosum parents. Discrimination between hybrid families and their relationship to their parents provides information of value in determining future breeding strategies.

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