scholarly journals Understanding significance and p-values

2016 ◽  
Vol 6 (1) ◽  
pp. 522
Author(s):  
Shrikant I Bangdiwala
Keyword(s):  
Confidence Interval ◽  
Scientific Reasoning ◽  
P Value ◽  
P Values ◽  
Single Index ◽  
Measure Of Uncertainty

<p>Since the p-value is a single index, following the ASA’s statement, we strongly support that it cannot and should not be considered as the sole basis for scientific reasoning. Given the misuses and misconceptions concerning p-values, the recommendation is to present the estimate of the effect, provide a measure of uncertainty of the estimation (e.g. confidence interval), and interpret the results in terms of scientific importance. </p>

scholarly journals Understanding significance and p-values

2016 ◽  
Vol 6 (1) ◽  
pp. 522-24 ◽  
Author(s):  
Shrikant I Bangdiwala
Keyword(s):  
Confidence Interval ◽  
Scientific Reasoning ◽  
Statistical Significance ◽  
P Value ◽  
P Values ◽  
Single Index ◽  
Measure Of Uncertainty

Correction 7th May 2016: p.523, Column 1, second paragraph, line 10 - 'the quantiles at the extremes - say 5%, 1%, which were useful' was changed TO 'the quantiles at the extremes - say 10%, 5%, 2%, and 1%, which were useful'.p.523, Column 2, second paragraph, line 3 - 'this is misconstrued with 'statistical significance' changed TO 'mistaken with 'statistical significance'.Since the p-value is a single index, following the ASA’s statement, we strongly support that it cannot and should not be considered as the sole basis for scientific reasoning. Given the misuses and misconceptions concerning p-values, the recommendation is to present the estimate of the effect, provide a measure of uncertainty of the estimation (e.g. confidence interval), and interpret the results in terms of scientific importance. 

scholarly journals Visualization Strategies for Regression Estimates with Randomization Inference

2019 ◽  
Author(s):  
Marshall A. Taylor
Keyword(s):  
Confidence Interval ◽  
Confidence Intervals ◽  
Regression Models ◽  
Statistical Significance ◽  
Permutation Tests ◽  
P Value ◽  
P Values ◽  
Alpha Level ◽  
Significance Levels ◽  
Nonprobability Sample

Coefficient plots are a popular tool for visualizing regression estimates. The appeal of these plots is that they visualize confidence intervals around the estimates and generally center the plot around zero, meaning that any estimate that crosses zero is statistically non-significant at at least the alpha-level around which the confidence intervals are constructed. For models with statistical significance levels determined via randomization models of inference and for which there is no standard error or confidence intervals for the estimate itself, these plots appear less useful. In this paper, I illustrate a variant of the coefficient plot for regression models with p-values constructed using permutation tests. These visualizations plot each estimate's p-value and its associated confidence interval in relation to a specified alpha-level. These plots can help the analyst interpret and report both the statistical and substantive significance of their models. Illustrations are provided using a nonprobability sample of activists and participants at a 1962 anti-Communism school.

scholarly journals Visualization strategies for regression estimates with randomization inference

2020 ◽  
Vol 20 (2) ◽  
pp. 309-335
Author(s):  
Marshall A. Taylor
Keyword(s):  
Confidence Interval ◽  
Confidence Intervals ◽  
Regression Models ◽  
Statistical Significance ◽  
Permutation Tests ◽  
P Value ◽  
P Values ◽  
Alpha Level ◽  
Significance Levels ◽  
Nonprobability Sample

Coefficient plots are a popular tool for visualizing regression estimates. The appeal of these plots is that they visualize confidence intervals around the estimates and generally center the plot around zero, meaning that any estimate that crosses zero is statistically nonsignificant at least at the alpha level around which the confidence intervals are constructed. For models with statistical significance levels determined via randomization models of inference and for which there is no standard error or confidence intervals for the estimate itself, these plots appear less useful. In this article, I illustrate a variant of the coefficient plot for regression models with p-values constructed using permutation tests. These visualizations plot each estimate’s p-value and its associated confidence interval in relation to a specified alpha level. These plots can help the analyst interpret and report the statistical and substantive significances of their models. I illustrate using a nonprobability sample of activists and participants at a 1962 anticommunism school.

HUBUNGAN KARAKTERISTIK PASIEN DENGAN PEMAHAMAN PERSETUJUAN TINDAKAN MEDIS PADA TINDAKAN BEDAH DI RUMAH SAKITPERTAMINA BINTANG AMIN (RSPBA) BANDAR LAMPUNG BULAN MARET 2015

2019 ◽  
Vol 6 (1) ◽  
pp. 19-28
Author(s):  
Rakhmie Rafie ◽  
Yusmaidi Yusmaidi ◽  
Mira Fitriyani
Keyword(s):  
Informed Consent ◽  
Confidence Interval ◽  
P Value ◽  
Chi Square ◽  
Cross Sectional

Berdasarkan Permenkes 585/1989 dikatakan bahwa informed consent adalah persetujuan yang diberikan oleh pasien atau keluarganya atas dasar penjelasan mengenai tindakan medis yang akan dilakukan terhadap pasien tersebut. Peran dan tanggung jawab dokter terhadap pelaksanaan tindakan medis berdasarkan imformed consent sangat penting untuk mencegah kemungkinan yang akan terjadi kepada pasien nantinya. Pemahaman terhadap informasi yang diberikan dipengaruhi oleh beberapa faktor, diantaranya karakteristik orang tersebut. Survey analitik dengan desain cross sectional dengan wawancara terpimpin menggunakan kuesioner terhadap 100 responden, dan diolah menggunakan analisa univariat dan bivariat dengan uji Chi-Square. Hasil penelitian menunjukkan bahwa: yang berusia dewasa 84 responden (84%) dan yang berusia muda sebanyak 16 responden (16%), laki- laki 63 responden (63%) dan perempuan 37 responden (37%), yang berpendidikan rendah 41 responden (41%) dan yang berpendidikan tinggi 59 responden, yang tidak bekerja 24 responden (24%) sedangkan yang bekerja 76 responden (76%), yang mempunyai pemahaman baik 58 responden (58%) dan yang tidak baik sebanyak 42 responden (42%). Variabel yang terdapat hubungan bermakna dengan pemahaman terhadap persetujuan tindakan medis pada tindakan bedah di RSPBA pada bulan Maret 2015 adalah umur (nilai p value = 0,037) OR = 3.761 dengan nilai Confidence Interval (1.195-11.835)dan pendidikan (nilai p value = 0,00) OR = 8.551 dengan Confidence Interval (3.436-21.285). Sedangkan variabel yang tidak terdapat hubungan bermakna dengan pemahaman persetujuan tindakan medispada tindakan bedah di RSPBA pada bulan Maret 2015 adalah jenis kelamin (nilai p value = 0,987) dan pekerjaan (p value = 0,251). Terdapat hubungan bermakna antara umur dan pendidikan dengan pemahaman terhadap persetujuan tindakan medis pada tindakan bedah di RS Pertamina Bintang Aamin (RSPBA) pada bulan Maret 2015.  

scholarly journals Association of interleukin-17A rs2275913 polymorphism with rheumatoid arthritis susceptibility in Sudanese population

2021 ◽  
Vol 9 ◽  
pp. 205031212110202
Author(s):  
Rgda Mohamed Osman ◽  
Mounkaila Noma ◽  
Abdallah Elssir Ahmed ◽  
Hanadi Abdelbagi ◽  
Rihab Ali Omer ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
Confidence Interval ◽  
Statistical Tests ◽  
Demographic Data ◽  
Control Group ◽  
P Value ◽  
Case Group ◽  
Molecular Technique ◽  
Interleukin 17A ◽  
Significant Difference

Objectives: Rheumatoid arthritis is a chronic inflammatory autoimmune disease. This study aimed to determine the association of interleukin-17A-197G/A polymorphism with rheumatoid arthritis in Sudanese patients. Methods: A case–control study was conducted between March and December 2018. Clinical and demographic data of the study participants were collected and analyzed. Polymerase chain reaction restriction fragment length polymorphism molecular technique was done to investigate interleukin-17A-197G/A polymorphisms. All statistical tests were considered statistically significant when p < 0.05. Results: The study population included 266 participants aged between 1 and 85 years, with an average of 40 years, classified into 85 (31.2%) cases (mean age 48.5 ± 11.3 years), and 181 (68.8%) controls (mean age 35.3 ± 15.9 years). The interleukin-17A homozygote AA genotype was more frequent among the control group compared to the case group; 95 (52.5%) and 7 (8.2%), respectively. The homozygote GG and the heterozygote AG genotypes were proportionally not different among the cases and control groups; 13 (54.2%) and 11 (45.8%), and 65 (46.4%) and 75 (53.6%), respectively. According to the distribution of interleukin-17A genotypes, a statistically significant difference was observed among cases with the interleukin-17A AA and AG genotypes, p values 0.001 and 0.004, respectively. For the association interleukin-17A genotypes and family history a negatively significant association was reported (95% confidence interval, –0.219, p value = 0.001). There was also a negatively significant association of interleukin-17A genotypes and anti-cyclic citrullinated peptide (95% confidence interval, −0.141, p value = 0.002). Conclusion: This study is the first study in Sudan established the association between interleukin-17A-197G/A (rs2275913) polymorphisms and susceptibly to rheumatoid arthritis. These findings appeal for further research in Sudan to investigate the exact role of IL-17A in immunopathology and disease severity among Sudanese rheumatoid arthritis

scholarly journals Prostate cancer screening: A survey of medical students’ knowledge in Lome, Togo, and associated determinants in a resource-limited African context

2021 ◽  
Vol 9 ◽  
pp. 205031212110328
Author(s):  
Tchin Darré ◽  
Toukilnan Djiwa ◽  
Tchilabalo Matchonna Kpatcha ◽  
Albadia Sidibé ◽  
Edoé Sewa ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Cancer Screening ◽  
Medical Students ◽  
Confidence Interval ◽  
Prostate Cancer Screening ◽  
Specific Antigen ◽  
Digital Rectal Examination ◽  
P Value ◽  
Theoretical Knowledge ◽  
Practical Level

Objectives: The aims of this study were to assess the knowledge of medical students in Lomé about these means of screening for prostate cancer in a context of limited resources and controversy about prostate cancer screening, and to identify the determinants associated with these results. Methods: This was a prospective descriptive and cross-sectional study conducted in the form of a survey of medical students regularly enrolled at the Faculty of Health Sciences of the University of Lomé for the 2019–2020 academic years. Results: Of the 1635 eligible students, 1017 correctly completed the form, corresponding to a rate of 62.20%. The average age was 22 ± 3.35 years. The sex ratio (M/F) was 2.5. Undergraduate students were the most represented (53.69%). Students who had not received any training on prostate cancer were the most represented (57.13%). Only 12.88% of the students had completed a training course in urology. Concerning the prostate-specific antigen blood test, there was a statistically significant relationship between the students’ knowledge and some of their socio-demographic characteristics, namely age (p value = 0.0037; 95% confidence interval (0.50–1.77)); gender (p value = 0.0034; 95% confidence interval (1.43–2.38)); study cycle (p value ˂ 0.0001; 95% confidence interval (0.56–5.13)) and whether or not they had completed a placement in a urology department (p value ˂ 0.0001; 95% confidence interval (0.49–1.55)). On the contrary, there was no statistically significant relationship between students’ knowledge of the digital rectal examination and their study cycle (p value = 0.082; 95% confidence interval (0.18–3.44)). Conclusion: Medical students in Lomé have a good theoretical knowledge and a fair practical level of the digital rectal examination clinical examination and an average theoretical knowledge and a below average practical level of prostate-specific antigen, increasing however along the curriculum in the context of prostate cancer screening.

scholarly journals SAT0210 FACTORS ASSOCIATED WITH TIME TO SEVERE LUPUS NEPHRITIS IN A COHORT OF COLOMBIAN PATIENTS

2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 1048.2-1048
Author(s):  
S. Herrera ◽  
J. C. Diaz-Coronado ◽  
D. Rojas-Gualdrón ◽  
L. Betancur-Vasquez ◽  
D. Gonzalez-Hurtado ◽  
...  
Keyword(s):  
Lupus Nephritis ◽  
Renal Involvement ◽  
Classification Criteria ◽  
P Value ◽  
Systemic Lupus ◽  
P Values ◽  
Interval Censored ◽  
Severe Lupus Nephritis ◽  
Age And Sex

Background:Systemic lupus erythematosus (SLE) clinical manifestations, and their severity, vary according to age, ethnicity and socioeconomic status. Both Hispanic and Afro-Americans have a higher incidence and more sever presentation when compared to Caucasian patients with SLEObjectives:To analyze clinical and immunological characteristics associated with time to severe renal involvement in patients with Systemic Lupus Erythematous in a Colombian cohort followed for one year, between January 2015 and December 2018Methods:Retrospective follow-up study based in clinical records. Patients with SLE diagnosis that fulfilled either 1987 American College of Rheumatology Classification Criteria for SLE or 2011 Systemic Lupus International Collaborating Clinics (SLICC) classification criteria for SLE. We included patients with diagnosis of lupus nephritis according to Wallace and Dubois criteria. Patients who did not have at least two follow-up measurements or had a cause of nephritis other than lupus were excluded. The main outcome was defined as time from diagnosis to sever renal involvement defined as creatinine clearance ≤50 ml/min, 24-hour proteinuria ≥3.5 grams o end stage renal disease.We analyzed clinical and immunological characteristics. Descriptive statistical analyses of participant data during the first evaluation are reported as frequencies and percentages for categorical variables, and as medians and interquartile ranges (IQR) for quantitative variables. Age and sex adjusted survival functions and Hazard ratios (HR) with 95% confidence intervals and p-values were estimated using parametric Weibull models por interval-censored data. P values < 0.05 were considered statistically significantResults:548 patients were analyzed: 67 were left-censored as they presented renal involvement at entry, 6 were interval censored as outcome occurred between study visits, and 475 were right-censored as involvement was not registered during follow-up. 529 (96.5%) patients were female, median age at entry was 46 (IQR = 23) and median age to diagnosis was 29.5 (IQR = 20.6). 67% were mestizo, 13% Caucasian and 0.3% Afro-Colombian. Age and sex adjusted variables associated with time to severe lupus nephritis were high blood pressure HR = 3.5 (95%CI 2.2-5.6; p-value <0.001) and Anti-RO (per unit increase) HR = 1.002 (95%CI 1.001-1.004; p-value = 0.04). Figure 1 shows age and sex adjusted survival function.Conclusion:In our cohort the appearance of severe lupus nephritis occurs in less than 15% of patients at 10 years. Both high blood pressure and elevated anti-Ro titers were associated with a higher rate of onset in the presentation of severe lupus nephritis, as seen in some polymorphs of anti Ro.References:Disclosure of Interests:Sebastian Herrera Speakers bureau: academic conference, Juan camilo Diaz-Coronado: None declared, Diego Rojas-Gualdrón: None declared, Laura Betancur-Vasquez: None declared, Daniel Gonzalez-Hurtado: None declared, Juanita Gonzalez-Arango: None declared, laura Uribe-Arango: None declared, Maria Fernanda Saavedra Chacón: None declared, Jorge Lacouture-Fierro: None declared, Santiago Monsalve: None declared, Sebastian Guerra-Zarama: None declared, Juan david Lopez: None declared, Juan david Serna: None declared, Julian Barbosa: None declared, Ana Sierra: None declared, Deicy Hernandez-Parra: None declared, Ricardo Pineda.Tamayo: None declared

scholarly journals Asymptotic normality of conditional distribution estimation in the single index model

2017 ◽  
Vol 9 (1) ◽  
pp. 162-175
Author(s):  
Diaa Eddine Hamdaoui ◽  
Amina Angelika Bouchentouf ◽  
Abbes Rabhi ◽  
Toufik Guendouzi
Keyword(s):  
Distribution Function ◽  
Confidence Interval ◽  
Asymptotic Normality ◽  
Conditional Distribution ◽  
Conditional Distribution Function ◽  
Single Index ◽  
Index Model ◽  
Single Index Model ◽  
Distribution Estimation

AbstractThis paper deals with the estimation of conditional distribution function based on the single-index model. The asymptotic normality of the conditional distribution estimator is established. Moreover, as an application, the asymptotic (1 − γ) confidence interval of the conditional distribution function is given for 0 < γ < 1.

scholarly journals Peripartum depression in parents with multiple sclerosis and psychiatric disorders in children

2016 ◽  
Vol 22 (14) ◽  
pp. 1830-1840 ◽  
Author(s):  
Neda Razaz ◽  
Helen Tremlett ◽  
Ruth Ann Marrie ◽  
K.S. Joseph
Keyword(s):  
Multiple Sclerosis ◽  
Cohort Study ◽  
Confidence Interval ◽  
Psychiatric Disorders ◽  
Physician Visit ◽  
Drug Prescription ◽  
P Value ◽  
Potential Association ◽  
Unaffected Parent ◽  
Peripartum Depression

Background: Although many individuals with multiple sclerosis (MS) experience depression, there are no studies on the frequency and effect of peripartum depression among parents with MS. Objective: To examine the frequency of peripartum depression in individuals with MS and its potential association with children’s psychiatric disorders. Methods: We conducted a cohort study in British Columbia, Canada, using linked health databases, of parents with MS and their children, and age-matched unaffected parent–child dyads. The diagnosis of peripartum depression, MS and psychiatric disorders in children was based on information from hospital admission, physician visit and drug prescription claims. Results: Peripartum depression was significantly more common among MS parents ( n = 360) versus unaffected ( n = 1207) parents (25.8% vs 18.5%, p value 0.02), especially among MS affected fathers versus unaffected fathers (25.7% vs 10.2%, p value < 0.001). The incidence of psychiatric disorders in children was 3.3 and 2.7 per 100 child-years among children with and without an MS parent, respectively. The rate of psychiatric disorders was significantly higher in children with an MS parent (vs without, hazard ratio (HR): 1.34; 95% confidence interval (CI): 1.03–1.74) and among children with parents who had peripartum depression (HR: 1.87; 95% CI: 1.36–2.55). Conclusion: Parental MS is associated with a higher risk of peripartum depression and increases the risk of psychiatric disorders in children.

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