scholarly journals Statistical Rituals: The Replication Delusion and How We Got There

2018 ◽  
Vol 1 (2) ◽  
pp. 198-218 ◽  
Author(s):  
Gerd Gigerenzer

The “replication crisis” has been attributed to misguided external incentives gamed by researchers (the strategic-game hypothesis). Here, I want to draw attention to a complementary internal factor, namely, researchers’ widespread faith in a statistical ritual and associated delusions (the statistical-ritual hypothesis). The “null ritual,” unknown in statistics proper, eliminates judgment precisely at points where statistical theories demand it. The crucial delusion is that the p value specifies the probability of a successful replication (i.e., 1 – p), which makes replication studies appear to be superfluous. A review of studies with 839 academic psychologists and 991 students shows that the replication delusion existed among 20% of the faculty teaching statistics in psychology, 39% of the professors and lecturers, and 66% of the students. Two further beliefs, the illusion of certainty (e.g., that statistical significance proves that an effect exists) and Bayesian wishful thinking (e.g., that the probability of the alternative hypothesis being true is 1 – p), also make successful replication appear to be certain or almost certain, respectively. In every study reviewed, the majority of researchers (56%–97%) exhibited one or more of these delusions. Psychology departments need to begin teaching statistical thinking, not rituals, and journal editors should no longer accept manuscripts that report results as “significant” or “not significant.”

2021 ◽  
Author(s):  
Neil McLatchie ◽  
Manuela Thomae

Thomae and Viki (2013) reported that increased exposure to sexist humour can increase rape proclivity among males, specifically those who score high on measures of Hostile Sexism. Here we report two pre-registered direct replications (N = 530) of Study 2 from Thomae and Viki (2013) and assess replicability via (i) statistical significance, (ii) Bayes factors, (iii) the small-telescope approach, and (iv) an internal meta-analysis across the original and replication studies. The original results were not supported by any of the approaches. Combining the original study and the replications yielded moderate evidence in support of the null over the alternative hypothesis with a Bayes factor of B = 0.13. In light of the combined evidence, we encourage researchers to exercise caution before claiming that brief exposure to sexist humour increases male’s proclivity towards rape, until further pre-registered and open research demonstrates the effect is reliably reproducible.


2020 ◽  
Vol 31 (7) ◽  
pp. 858-864 ◽  
Author(s):  
Will M. Gervais ◽  
Stephanie E. McKee ◽  
Sarah Malik

Do reminders of God encourage people to take more risks? Kupor, Laurin, and Levav (2015) reported nine studies that all yielded statistically significant results consistent with the hypothesis that they do. We conducted two large-sample Preregistered Direct Replications ( N = 1,104) of studies in Kupor et al.’s article (Studies 1a and 1b) and evaluated replicability via (a) statistical significance, (b) a “small-telescopes” approach, (c) Bayes factors (BFs), and (d) meta-analyses pooled across original and replication studies. None of these approaches replicated the original studies’ effects. Combining both original studies and both replications yielded strong evidence in support of the null over a default alternative hypothesis, BF01 = 11.04, meaning that the totality of evidence speaks against the possibility that religious primes increased nonmoral risk taking in these designs. This suggests that support for the “anticipating-divine-protection” hypothesis may be overstated.


2018 ◽  
Author(s):  
Will M Gervais ◽  
Stephanie Elizabeth McKee ◽  
Sarah Malik

Do reminders of God encourage people to take more risks? A recent paper (Kupor, Laurin, & Levav, 2015) reported 9 studies that all yielded statistically significant results consistent with hypothesis. We conducted two large-sample preregistered direct replications (total N = 1104) of studies in this paper (Studies 1a and 1b), and evaluated replicability via 1) statistical significance, 2) a “small telescopes” approach (Simonsohn, 2015), 3) Bayes factors (Gronau, Ly, & Wagenmakers, 2017), and 4) meta-analyses pooling across original and replication studies. None of these approaches found replicable effects. Combining both original studies and both replications yields strong evidence in support of the null over a default alternative hypothesis, BF01 = 11.04, meaning that the totality of evidence speaks against the possibility that religious primes increase nonmoral risk taking in these designs. This suggests that support for the “anticipating divine protection” hypothesis may be overstated. Preprint https://psyarxiv.com/8f7qd/


Author(s):  
Pawan Kumar Saini ◽  
Devendra Yadav ◽  
Rozy Badyal ◽  
Suresh Jain ◽  
Arti Singh ◽  
...  

Background: Psoriasis is an autoimmune chronic inflammatory disorder affecting the skin mediated by T-lymphocytes resulting in production of cytokines which cause hyperproliferation of keratinocytes.  Several factors and hormones like Prolactin have an action similar to these cytokines in promoting the multiplication of keratinocytes and other cells like lymphocytes and epithelial cells may have a role on the etiopathogenesis of psoriasis. Aim:-The aim of study is to compare the serum Prolactin levels in patients of psoriasis with a control group. Setting and study design: This is a case-control study conducted in the department of Dermatology, Venereology and Leprosy GMC, Kota over a period of 1year from July 2017 to June 2018 Material and method: The study included 100 cases of psoriasis (60 males and 40 females) and 100 controls similar for age and sex. Serum Prolactin levels were measured by ECLIA and results were obtained. Statistical analysis: Mean and standard deviation were calculated for each variable. Statistical significance of the results was analyzed using correlation analysis (Pearson correlation coefficient) and independent samples t-test. Statistical significance was assumed at p value<0.05. Result: Serum Prolactin level was significantly higher in cases of psoriasis compared to controls (p-value <0.001). PASI score and serum Prolactin levels were found to have a positive correlation (r value = 0.337; p-value: 0.001). No significant  correlation was found between serum levels of Prolactin and duration of disease r value= -0.034, P value =0.733). Serum Prolactin level was higher in male patients compared to females patients. Conclusion:- High serum Prolactin may be a biological marker of disease severity in psoriasis and may have a role in the pathogenesis of psoriasis. Further studies with large sample size are required to confirm this hypothesis.


2019 ◽  
Author(s):  
Bashayer Hassan Shuaib ◽  
Rahaf Hisham Niazi ◽  
Ahmed Haitham Abduljabbar ◽  
Mohammed Abdulraheem Wazzan

BACKGROUND Radiology now plays a major role to diagnose, monitoring, and management of several diseases; numerous diagnostic and interventional radiology procedures involve exposure to ionizing radiation. Radiology now plays a major role to diagnose, monitoring, and management of several diseases; numerous diagnostic and interventional radiology procedures involve exposure to ionizing radiation. OBJECTIVE This study aimed to discover and compare the awareness level of radiation doses, protection issues, and risks among radiology staff in Jeddah hospitals. METHODS A cross-sectional survey containing 25 questions on personal information and various aspects of radiation exposure doses and risks was designed using an online survey tool and the link was emailed to all radiology staff in eight tertiary hospitals in Jeddah. The authors were excluded from the study. A P-value of < .05 was used to identify statistical significance. All analyses were performed using SPSS, version 21. RESULTS Out of 156 participants the majority 151 (96.8%) had poor knowledge score, where the mean scores were 2.4±1.3 for doses knowledge, 2.1±1.1for cancer risks knowledge, 2.3±0.6 for general information, and 6.7±1.9 for the total score. Only 34.6% of the participants were aware of the dosage of a single-view chest x-ray, and 9.0% chose the right answer for the approximate effective dose received by a patient in a two-view. 42.9% were able to know the correct dose of CT abdomen single phase. There is a significant underestimation of cancer risk of CT studies especially for CT abdomen where only 23.7% knew the right risk. A p-value of <0.05 was used to identify statistical significance. No significant difference of knowledge score was detected regarding gender (P =.2) or work position (P=.66). CONCLUSIONS Our survey results show considerable inadequate knowledge in all groups without exception. We recommended a conscientious effort to deliver more solid education and obtain more knowledge in these matters and providing periodic training courses to teach how to minimize the dose of radiation and to avoid risk related. CLINICALTRIAL not applicable


Author(s):  
Mariam Raafat ◽  
Soha H. Talaat ◽  
Salma M. Abdelghaffar ◽  
Engy A. Ali

Abstract Background Endometriosis is a common gynecologic disorder characterized by the implantation of the endometrial tissue ectopically outside the endometrial cavity. It affects about 10% of females at the childbearing period and is estimated to be present up to 20–50% in women complaining of infertility. While laparoscopy is considered the mainstay for diagnosis, magnetic resonance imaging (MRI) is recognized as a useful tool for definitive diagnosis, pre-surgical planning, and determining whether the patient will require multi-specialty involvement. The aim of this study is to evaluate the performance of MRI with the addition of diffusion-weighted imaging (DWI) and T2 star (T2*) to conventional MRI, for the accurate assessment of ectopic endometrium. Results Endometriotic lesions that showed diffusion restriction on DWI were 80.7%, and 96.1% of the endometriotic lesions had signal voids on the T2*W sequence, whereas only 65.4% of the lesions had typical signal intensities on T1WI and T2WI. Diagnostic performance of the MRI examination was improved by the use of the diffusion sequence and better improved by the T2* sequence, compared to the conventional MR protocol sensitivity (SE) = 96.12% and specificity (SP) = 85.7% in T2*-weighted images, SE = 80.7% and SP = 71.4% in DWI, and SE = 65.4% and SP = 71.4% in conventional MRI. P value for conventional MRI was 0.1, which is of no statistical significance (p < 0.05). P value for DWI was 0.016, which is statistically significant (p < 0.05). P value for T2*WI was 0.001, which is more statistically significant (p < 0.05) and could be adequately correlated with laparoscopy. Conclusion DWI and T2* significantly increase MRI diagnostic accuracy by allowing the detection of the hemorrhagic character of the endometriotic lesions. Studies with a large sample size are needed to confirm that they can replace invasive laparoscopy for the diagnosis of endometriosis.


2021 ◽  
pp. 159101992110259
Author(s):  
Kainaat Javed ◽  
Santiago R Unda ◽  
Ryan Holland ◽  
Adisson Fortunel ◽  
Rose Fluss ◽  
...  

Introduction Flow diversion is an effective treatment modality for intracranial aneurysms but is associated with ischemic and hemorrhagic complications. Patients treated with flow diversion require dual antiplatelet therapy and subsequent platelet function tests. At our institution, Thromboelastography with Platelet Mapping (TEG-PM) is the test of choice. The primary objective of this study was to identify TEG parameters that are predictive of postoperative complications in patients treated with elective flow diversion. Methods This was a retrospective study of 118 patients with unruptured intracranial aneurysms treated with flow diversion. Data was collected via chart review. Bivariate analyses were performed to identify significant variables in patients who suffered an ischemic stroke or a groin hematoma. ROC curves were constructed for the TEG parameters with statistical significance. Bivariate analyses were repeated using dichotomized TEG results. Results Patients who experienced a symptomatic ischemic stroke had a history of stroke (p value = 0.007), larger aneurysm neck width (p value = 0.017), and a higher alpha angle (p value = 0.013). Cut off point for ischemic complication is 63° on ROC curve with a sensitivity of 100% and specificity of 65%. Patients who experienced a groin hematoma were no different from their healthy peers but had a lower alpha angle (p value = 0.033). Cut off point for hemorrhagic complication is 53.3° with a sensitivity of 82% and specificity of 67%. Conclusion The Alpha Angle parameter of TEG-PM has a sizeable predictive ability for both ischemic complications of the central nervous system and hemorrhagic complications of the access site after elective flow diversion.


Author(s):  
Kemar J Brown ◽  
Njambi Mathenge ◽  
Daniela Crousillat ◽  
Jaclyn Pagliaro ◽  
Connor Grady ◽  
...  

Abstract Background The coronavirus disease 2019 (COVID-19) pandemic has resulted in the rapid uptake of telemedicine (TM) for routine cardiovascular care. Objectives To examine the predictors of TM utilization among ambulatory cardiology patients during the COVID-19 pandemic. Methods In this single centre retrospective study, all ambulatory cardiovascular encounters occurring between March 16th - June 19th, 2020 were assessed. Baseline characteristics by visit type (in-person, TM-phone, TM-video) were compared using Chi-square and student t-tests, with statistical significance defined by p value &lt; 0.05. Multivariate logistic regression was used to explore the predictors of TM versus in-person care. Results 8446 patients (86% Non-Hispanic White, 42% female, median age 66.8 +/- 15.2 years) completed an ambulatory cardiovascular visit during the study period. TM-phone (n = 4,981, 61.5%) was the primary mode of ambulatory care followed by TM-video (n = 2693, 33.2%). Non-Hispanic Black race (OR 0.56; 95% CI: 0.35 - 0.94, p-value=0.02), Hispanic ethnicity (OR 0.53; 95% CI: 0.29 - 0.98, p = 0.04), public insurance (Medicaid OR 0.50; 95% CI:0.32 – 0.79, p = 0.003, Medicare OR 0.65; 95% CI: 0.47– 0.89, p = 0.009), zip-code linked median household income (MHI) of &lt;$75,000, age &gt;85 years, and patients with a diagnosis of heart failure were associated with reduced access to TM-video encounters and a higher likelihood of in-person care. Conclusions Significant disparities in TM-video access for ambulatory cardiovascular care exist among the elderly, lower income, as well as Black and Hispanic racial/ethnic groups.


2021 ◽  
pp. 154431672110303
Author(s):  
Sayan Sarkar ◽  
Shyam Mohan ◽  
Shakthi Parvathy

The purpose of this study is to analyze how accurate duplex ultrasonography using color Doppler and computed tomography (CT) angiography are in detection of peripheral arterial disease (PAD) in comparison with the Gold Standard of digital subtraction angiography (DSA). This is a single-center prospective, analytical study done on patients with symptoms of PAD referred to the Department of Radiodiagnosis of Medical Trust Hospital (n = 53). All patients were imaged with color Doppler, CT angiography, and DSA. The peak systolic velocity (PSV) ratio was calculated by Doppler ultrasound, and the percentage stenosis for the same vascular segments was calculated using CT angiography and DSA. To test the statistical significance between the results, chi-square test was used. A P value <.05 indicates statistical significance. The PSV ratio for each grade—normal (<1.5), mild (1.5-2.8), moderate (2.9-4.9), and severe (≥5)—and the percentage of stenosis for each grade observed on CT angiography—normal (<20% stenosis), mild (20%-49% stenosis), moderate (50%-74% stenosis), severe (75%-99% stenosis), and total occlusion (100% stenosis)—were found to be highly sensitive and specific with good positive predictive value, negative predictive value, and accuracy level when compared with DSA with narrow confidence intervals for each range. The P value was <.001 for both color Doppler and CT angiography. Computed tomography angiography can be an effective tool as an alternative to DSA for gradation of stenosis if the artifacts resulting from vascular calcification can be avoided. Duplex ultrasonography can be utilized for gradation of stenosis by using the value of PSV ratio and spectral pattern together. However, it can only act as an adjunct to CT angiography because it is incapable of imaging the full length of the arterial segments in 1 frame.


Cancers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1624
Author(s):  
Christos G. Gavriel ◽  
Neofytos Dimitriou ◽  
Nicolas Brieu ◽  
Ines P. Nearchou ◽  
Ognjen Arandjelović ◽  
...  

The clinical staging and prognosis of muscle-invasive bladder cancer (MIBC) routinely includes the assessment of patient tissue samples by a pathologist. Recent studies corroborate the importance of image analysis in identifying and quantifying immunological markers from tissue samples that can provide further insight into patient prognosis. In this paper, we apply multiplex immunofluorescence to MIBC tissue sections to capture whole-slide images and quantify potential prognostic markers related to lymphocytes, macrophages, tumour buds, and PD-L1. We propose a machine-learning-based approach for the prediction of 5 year prognosis with different combinations of image, clinical, and spatial features. An ensemble model comprising several functionally different models successfully stratifies MIBC patients into two risk groups with high statistical significance (p value < 1×10−5). Critical to improving MIBC survival rates, our method correctly classifies 71.4% of the patients who succumb to MIBC, which is significantly more than the 28.6% of the current clinical gold standard, the TNM staging system.


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