Peter Cahusac | Alfaisal University (original) (raw)
Drafts by Peter Cahusac
jeva module in jamovi, 2022
This is a jamovi module for log likelihood ratio analyses of common statistical tests (jeva <jamo... more This is a jamovi module for log likelihood ratio analyses of common statistical tests (jeva <jamovi evidential analyses) jamovi is a brilliant way to do statistics. It is open statistical software built on top of the powerful R statistical language. Moreover, it is free.
Papers by Peter Cahusac
The American Journal of Sports Medicine, 2025
Background: Patellar instability is frequently encountered by orthopaedic surgeons. One of the ma... more Background: Patellar instability is frequently encountered by orthopaedic surgeons. One of the major risk factors of this condition
is underlying trochlear dysplasia (TD). Recent trends have indicated the use of multiple procedures to correct patellar instability
under these conditions. Medial patellofemoral ligament reconstruction (MPFLR) and trochleoplasty (TP) are surgical strategies
that have demonstrated successful outcomes. However, it is unclear whether isolated MPFLR suffices for patellar instability in
the presence of severe TD. Furthermore, the need for TP or a combined approach, considering its invasiveness and technical
demands, to achieve better clinical outcomes and patellofemoral stability remains uncertain.
Purpose: To compare the outcomes of 3 surgical interventions for addressing patellar instability due to TD: MPFLR, TP, and combined
MPFLR and TP.
Study Design: Systematic review and meta-analysis; Level of evidence, 4.
Methods: Studies reporting the clinical outcomes of MPFLR, TP, and both in combination, regardless of additional procedures, were
identified using the MEDLINE, PubMed, Embase, Scopus, Cochrane Library, Cochrane Central Register of Controlled Trials, and Cumulative
Index to Nursing and Allied Health Literature databases. An important inclusion criterion was that studies should include the mean
preoperative and postoperative Kujala scores and any complications. A random-effects model was used for the meta-analysis.
Results: Overall, 30 studies were included: 10 describing the outcomes of TP, 13 describing the outcomes of MPFLR, and 7
describing the outcomes of combined TP and MPFLR. Furthermore, 1457 patients (1571 knees) were evaluated with a mean
follow-up of 42.4 6 32.8 months. No statistically significant differences were found between the 3 methods regarding the
mean difference using the Kujala score. However, combined MPFLR and TP had the highest weighted mean difference compared
with the other 2 procedures (28.5 points; P\.001). Evidential analysis revealed a robust log-likelihood ratio (S = 3.2) supporting
the superiority of the combined procedure when comparing this mean and the weighted grand mean of 23.7. The redislocation
rate after patellar stabilization remained minimal, irrespective of the surgical procedure (mean, 0.7%). However, the rate of residual
patellar instability was the highest in the TP group (mean, 13.5%).
Conclusion: This study found no statistically significant difference between the outcomes of the 3 procedures. However, the
combined approach of MPFLR and TP was associated with the most promising clinical outcomes and a low redislocation rate
in patients with varying severities of TD.
Entropy, 2024
Categorical data analysis of 2 × 2 contingency tables is extremely common, not least because they... more Categorical data analysis of 2 × 2 contingency tables is extremely common, not least because they provide risk difference, risk ratio, odds ratio, and log odds statistics in medical research. A χ2
test analysis is most often used, although some researchers use likelihood ratio test (LRT) analysis. Does it matter which test is used? A review of the literature, examination of the theoretical foundations, and analyses of simulations and empirical data are used by this paper to argue that only the LRT should be used when we are interested in testing whether the binomial proportions are equal. This so-called test of independence is by far the most popular, meaning the χ2
test is widely misused. By contrast, the χ2
test should be reserved for where the data appear to match too closely a particular hypothesis (e.g., the null hypothesis), where the variance is of interest, and is less than expected. Low variance can be of interest in various scenarios, particularly in investigations of data integrity. Finally, it is argued that the evidential approach provides a consistent and coherent method that avoids the difficulties posed by significance testing. The approach facilitates the calculation of appropriate log likelihood ratios to suit our research aims, whether this is to test the proportions or to test the variance. The conclusions from this paper apply to larger contingency tables, including multi-way tables.
Journal of Infection and Public Health
Neuropharmacology, 1994
The selective glutamate metabotropic receptor agonist (lS,3R)-l-aminocyclopentane-1,3-dicarboxyli... more The selective glutamate metabotropic receptor agonist (lS,3R)-l-aminocyclopentane-1,3-dicarboxylic acid (lS,3R-ACPD) was applied iontophoretically to cells in the rat primary somatosensory cortex (SI) in vivo. In contrast to other in uivo studies, distinct excitatory and depressant effects were observed. The excitatory responses could not be blocked by ionotropic antagonists, as evidence that they were mediated by a metabotropic receptor. The depressant effects were most pronounced on natural synaptic transmission, suggesting that a presynaptic receptor may be involved, although responses to iontophoretically applied agonists were also affected. Comparison with the presumed presynaptic glutamate receptor agonist L-2-amino-4-phosphonobutyrate (L-AP4) suggest that the depressant effects of lS,3R-ACPD could be partially mediated by a presynaptic autoreceptor.
Behavioural Brain Research, Apr 1, 1986
Clinical and Translational Oncology, 2019
Background Malignant melanoma is a well-known and commonly lethal tumour yet there exists scarce ... more Background Malignant melanoma is a well-known and commonly lethal tumour yet there exists scarce published information available from Saudi Arabia. Materials and methods This study examined the demographic, clinical, and histopathological profile of melanoma in a sample of Saudi patients over a period of 13 years. Medical records of 98 patients from 2004 to 2016 were retrieved from the
Neuroscience Letters, 1982
The (D-Pro:, o-'l-rp 7,9) analogue of substance P has Vecn tested ;'or subslar~e .o antagonist ac... more The (D-Pro:, o-'l-rp 7,9) analogue of substance P has Vecn tested ;'or subslar~e .o antagonist ac!~,tty ~n the catdal trigeminal nucleus in ~ivo, an',:l in the isolated spinal cord in vitro. In neither tale ;-'-.~, tnc anaI, ogue found to be a specific antagonist of substaitc¢ ~, although the analogue did have v,'~'ak amagorfist actions in the isolated guinea-pig ikum preFarati~,-~. It is concluded ~N~t the ana!ogue is nut a suitable tool for the identification of putative subst~:nce P systems in tee spine! cord or the caudM trigeminai nucleus of the rat.
Skin Pharmacology and Physiology, 2020
Background: The pharmacological study of mechanoreceptors embedded within tissue is hampered by t... more Background: The pharmacological study of mechanoreceptors embedded within tissue is hampered by tissue barriers to applied research drugs. Methods: Hyaluronidase increases the permeability of tissues and is used clinically to facilitate the distribution of injected drugs. An in vitro rat sinus hair preparation was used to determine whether hyaluronidase (1,500 or 3,000 IU/10 mL) had an effect on drug access to receptor sites on slowly adapting St I and St II mechanoreceptors. Electrical recordings were made from single mechanoreceptor units that were activated by trapezoid ramp stimuli. Cinnamaldehyde (500–1,500 μM) and capsazepine (100 μM) were used as test drugs. Changes in onset time and degree of depression of firing due to test drugs were compared to control experiments not employing hyaluronidase. Results: There were no statistical effects on any of the observed measures. Often the effects were opposite to those predicted. Using a likelihood approach, it was calculated that there was strong evidence (log-likelihood ratios from −0.5 to −6.5) to support a null effect over a facilitatory effect. There was no evidence of loss of integrity of mechanoreceptor mechanotransduction mechanisms following hyaluronidase applications. Comparison with Existing Method: The use of hyaluronidase does not facilitate drug access to receptors. Conclusions: In the in vitro sinus hair preparation, the addition of hyaluronidase does not allow easier access to slowly adapting mechanoreceptors within the follicle.
Entropy, 2023
Categorical data analysis of 2 × 2 contingency tables is extremely common, not least because they... more Categorical data analysis of 2 × 2 contingency tables is extremely common, not least because they provide odds and risk ratio statistics in medical research. The χ 2 test is most often used, although some researchers use the likelihood ratio test (LRT). Does it matter which test is used? This paper argues that the LRT rather than the χ 2 test should be used when we are interested in testing whether two variables are independent, as is typically the case. In contrast, the χ 2 test should be reserved for where the data appear to match too closely a particular hypothesis (e.g. the null hypothesis), as may occur in the investigation of data integrity. Finally, it is argued that the evidential approach provides a consistent and coherent way in which tests can be made for each of these situations.
SSRN Electronic Journal
Introduction: slowly adapting mechanoreceptors in the skin provide vital tactile information to a... more Introduction: slowly adapting mechanoreceptors in the skin provide vital tactile information to animals. The ionic channels that underlie their functioning is the subject of intense research. Previous work suggests that potassium channels may play particular roles in the activation and firing of these mechanoreceptors. Objective: We used a range of potassium channel blockers and openers to observe their effects on different phases of mechanoreceptor responses. Methods: Extracellular recording of neural activity of slowly adapting mechanoreceptors was carried out in an in vitro preparation of the sinus hair follicles taken from rat whisker pads. A range of potassium (K +) channel modulators were tested on these mechanoreceptor responses. The channel blockers tested were: tetraethylammonium (TEA), barium chloride (BaCl 2), dequalinium, 4-aminopyridine (4-AP), paxilline, XE 991, apamin, and charybdotoxin. Results: Except for charybdotoxin and apamin, these drugs increased the activity of both types of slowly adapting units, St I and St II. Generally, both spontaneous and evoked (dynamic and static) activities increased. The channel opener NS1619 was also tested. NS1619 clearly decreased evoked activity (both dynamic and static) while leaving spontaneous activity relatively unaffected, with no clear discrimination of effects on the two types of St receptor Conclusion: These findings are consistent with the targets of the drugs suggesting that K + channels play an important role in the maintenance of spontaneous firing and in the production of and persistence of mechanoreceptor activity.
R Journal, 2022
The likelihoodR package has been developed to allow users to obtain statistics according to the l... more The likelihoodR package has been developed to allow users to obtain statistics according to the likelihood approach to statistical inference. Commonly used tests are available in the package, such as: t tests, ANOVA, correlation, regression and a range of categorical analyses. In addition, there is a sample size calculator for t tests, based upon the concepts of strength of evidence, and the probabilities of misleading and weak evidence.
![Research paper thumbnail of Likelihood Analyses for Common Statistical Tests [R package likelihoodR version 1.0.9]](https://attachments.academia-assets.com/97627310/thumbnails/1.jpg)
](Comprehensive R Archive Network (CRAN), Feb 11, 2023
Description A collection of functions that calculate the log likelihood (support) for a range of ... more Description A collection of functions that calculate the log likelihood (support) for a range of statistical tests. Where possible the likelihood function and likelihood interval for the observed data are displayed. The evidential approach used here is based on the book``Likelihood'' by A.W.F.
Frontiers in Cardiovascular Medicine
IntroductionThrombotic complications of coronavirus disease 2019 (COVID-19) have received conside... more IntroductionThrombotic complications of coronavirus disease 2019 (COVID-19) have received considerable attention. Although numerous conflicting findings have compared escalated thromboprophylaxis doses with a standard dose to prevent thrombosis, there is a paucity of literature comparing clinical outcomes in three different anticoagulation dosing regimens. Thus, we investigated the effectiveness and safety profiles of standard, intermediate, and high-anti-coagulation dosing strategies in COVID-19 critically ill patients.MethodologyThis retrospective multicenter cohort study of intensive care unit (ICU) patients from the period of April 2020 to August 2021 in four Saudi Arabian centers. Inclusion criteria were age ≥ 18 years, diagnosis with severe or critical COVID-19 infection, and receiving prophylactic anticoagulant dose within 24–48 h of ICU admission. The primary endpoint was a composite of thrombotic events, with mortality rate and minor or major bleeding serving as secondary e...
Research in Mathematics, 2022
The evidential approach uses likelihood ratios, typically the natural logarithm of the likelihood... more The evidential approach uses likelihood ratios, typically the natural logarithm of the likelihood ratio representing the amount of evidence for one hypothesis versus another. One of the barriers to using the approach is the unavailability of sample size calculations for commonly used statistical tests. The t test is the most common statistical test used in scientific publications. This paper derives the equations necessary to calculate evidential probabilities and hence the required sample size for different types of t tests. Compared with the conventional Neyman-Pearson approach, the evidential approach requires larger sample sizes. This drawback is countered by the fact that users know the probability for obtaining misleading evidence (strong evidence that points to the wrong hypothesis). Even with small sample sizes, this is quite small (around 0.05) and decreases further with increasing sample sizes. The main challenge faced by the evidential researcher is of obtaining sufficiently strong evidence for or against one of the two specified hypotheses. Like the probability of a Type II error, this probability is large with a small sample size and decreases as the sample size increases. Sample size is estimated by achieving a low probability (e.g. <.1) for the combined probability of misleading and weak evidence.
Saudi Medical Journal, 2021
To examine the awareness level of COVID-19 and to highlight the frequency of myths and misconcept... more To examine the awareness level of COVID-19 and to highlight the frequency of myths and misconceptions among Saudi Arabia's population. Methods: We conducted a cross-sectional study from June 13 to 20, 2020 by distributing a 16-item online Google forms questionnaire among adults)18-65 years old(living in Saudi Arabia. We utilized the convenience sampling. Data analysis was performed using Chi-square and multiple regression analysis on Jamovi. Results: A total of 1436 responses were analyzed with 43.5% males and 56.5% females. Most respondents)89.1%(thought that only the elderly above 60 years old are considered at high risk of contracting COVID-19. Most respondents)86.5%(agreed that people with other health conditions could be more affected by Original Article COVID-19. Approximately 97.2% agreed that wearing a mask and avoiding touching eyes, nose, and mouth with unwashed hands was the leading preventive action. Most participants)99.4%(chose fever as an associated symptom. Respondents from the healthcare sector presented statistically higher scores than those in non-healthcare sectors)p<0.001(. Higher education and higher salary were important predictors of better COVID-19 knowledge. Conclusion: Public health officials need to increase awareness measures on COVID-19 to limit myths and misconceptions and reduce psychological distress associated with it.
jeva module in jamovi, 2022
This is a jamovi module for log likelihood ratio analyses of common statistical tests (jeva <jamo... more This is a jamovi module for log likelihood ratio analyses of common statistical tests (jeva <jamovi evidential analyses) jamovi is a brilliant way to do statistics. It is open statistical software built on top of the powerful R statistical language. Moreover, it is free.
The American Journal of Sports Medicine, 2025
Background: Patellar instability is frequently encountered by orthopaedic surgeons. One of the ma... more Background: Patellar instability is frequently encountered by orthopaedic surgeons. One of the major risk factors of this condition
is underlying trochlear dysplasia (TD). Recent trends have indicated the use of multiple procedures to correct patellar instability
under these conditions. Medial patellofemoral ligament reconstruction (MPFLR) and trochleoplasty (TP) are surgical strategies
that have demonstrated successful outcomes. However, it is unclear whether isolated MPFLR suffices for patellar instability in
the presence of severe TD. Furthermore, the need for TP or a combined approach, considering its invasiveness and technical
demands, to achieve better clinical outcomes and patellofemoral stability remains uncertain.
Purpose: To compare the outcomes of 3 surgical interventions for addressing patellar instability due to TD: MPFLR, TP, and combined
MPFLR and TP.
Study Design: Systematic review and meta-analysis; Level of evidence, 4.
Methods: Studies reporting the clinical outcomes of MPFLR, TP, and both in combination, regardless of additional procedures, were
identified using the MEDLINE, PubMed, Embase, Scopus, Cochrane Library, Cochrane Central Register of Controlled Trials, and Cumulative
Index to Nursing and Allied Health Literature databases. An important inclusion criterion was that studies should include the mean
preoperative and postoperative Kujala scores and any complications. A random-effects model was used for the meta-analysis.
Results: Overall, 30 studies were included: 10 describing the outcomes of TP, 13 describing the outcomes of MPFLR, and 7
describing the outcomes of combined TP and MPFLR. Furthermore, 1457 patients (1571 knees) were evaluated with a mean
follow-up of 42.4 6 32.8 months. No statistically significant differences were found between the 3 methods regarding the
mean difference using the Kujala score. However, combined MPFLR and TP had the highest weighted mean difference compared
with the other 2 procedures (28.5 points; P\.001). Evidential analysis revealed a robust log-likelihood ratio (S = 3.2) supporting
the superiority of the combined procedure when comparing this mean and the weighted grand mean of 23.7. The redislocation
rate after patellar stabilization remained minimal, irrespective of the surgical procedure (mean, 0.7%). However, the rate of residual
patellar instability was the highest in the TP group (mean, 13.5%).
Conclusion: This study found no statistically significant difference between the outcomes of the 3 procedures. However, the
combined approach of MPFLR and TP was associated with the most promising clinical outcomes and a low redislocation rate
in patients with varying severities of TD.
Entropy, 2024
Categorical data analysis of 2 × 2 contingency tables is extremely common, not least because they... more Categorical data analysis of 2 × 2 contingency tables is extremely common, not least because they provide risk difference, risk ratio, odds ratio, and log odds statistics in medical research. A χ2
test analysis is most often used, although some researchers use likelihood ratio test (LRT) analysis. Does it matter which test is used? A review of the literature, examination of the theoretical foundations, and analyses of simulations and empirical data are used by this paper to argue that only the LRT should be used when we are interested in testing whether the binomial proportions are equal. This so-called test of independence is by far the most popular, meaning the χ2
test is widely misused. By contrast, the χ2
test should be reserved for where the data appear to match too closely a particular hypothesis (e.g., the null hypothesis), where the variance is of interest, and is less than expected. Low variance can be of interest in various scenarios, particularly in investigations of data integrity. Finally, it is argued that the evidential approach provides a consistent and coherent method that avoids the difficulties posed by significance testing. The approach facilitates the calculation of appropriate log likelihood ratios to suit our research aims, whether this is to test the proportions or to test the variance. The conclusions from this paper apply to larger contingency tables, including multi-way tables.
Journal of Infection and Public Health
Neuropharmacology, 1994
The selective glutamate metabotropic receptor agonist (lS,3R)-l-aminocyclopentane-1,3-dicarboxyli... more The selective glutamate metabotropic receptor agonist (lS,3R)-l-aminocyclopentane-1,3-dicarboxylic acid (lS,3R-ACPD) was applied iontophoretically to cells in the rat primary somatosensory cortex (SI) in vivo. In contrast to other in uivo studies, distinct excitatory and depressant effects were observed. The excitatory responses could not be blocked by ionotropic antagonists, as evidence that they were mediated by a metabotropic receptor. The depressant effects were most pronounced on natural synaptic transmission, suggesting that a presynaptic receptor may be involved, although responses to iontophoretically applied agonists were also affected. Comparison with the presumed presynaptic glutamate receptor agonist L-2-amino-4-phosphonobutyrate (L-AP4) suggest that the depressant effects of lS,3R-ACPD could be partially mediated by a presynaptic autoreceptor.
Behavioural Brain Research, Apr 1, 1986
Clinical and Translational Oncology, 2019
Background Malignant melanoma is a well-known and commonly lethal tumour yet there exists scarce ... more Background Malignant melanoma is a well-known and commonly lethal tumour yet there exists scarce published information available from Saudi Arabia. Materials and methods This study examined the demographic, clinical, and histopathological profile of melanoma in a sample of Saudi patients over a period of 13 years. Medical records of 98 patients from 2004 to 2016 were retrieved from the
Neuroscience Letters, 1982
The (D-Pro:, o-'l-rp 7,9) analogue of substance P has Vecn tested ;'or subslar~e .o antagonist ac... more The (D-Pro:, o-'l-rp 7,9) analogue of substance P has Vecn tested ;'or subslar~e .o antagonist ac!~,tty ~n the catdal trigeminal nucleus in ~ivo, an',:l in the isolated spinal cord in vitro. In neither tale ;-'-.~, tnc anaI, ogue found to be a specific antagonist of substaitc¢ ~, although the analogue did have v,'~'ak amagorfist actions in the isolated guinea-pig ikum preFarati~,-~. It is concluded ~N~t the ana!ogue is nut a suitable tool for the identification of putative subst~:nce P systems in tee spine! cord or the caudM trigeminai nucleus of the rat.
Skin Pharmacology and Physiology, 2020
Background: The pharmacological study of mechanoreceptors embedded within tissue is hampered by t... more Background: The pharmacological study of mechanoreceptors embedded within tissue is hampered by tissue barriers to applied research drugs. Methods: Hyaluronidase increases the permeability of tissues and is used clinically to facilitate the distribution of injected drugs. An in vitro rat sinus hair preparation was used to determine whether hyaluronidase (1,500 or 3,000 IU/10 mL) had an effect on drug access to receptor sites on slowly adapting St I and St II mechanoreceptors. Electrical recordings were made from single mechanoreceptor units that were activated by trapezoid ramp stimuli. Cinnamaldehyde (500–1,500 μM) and capsazepine (100 μM) were used as test drugs. Changes in onset time and degree of depression of firing due to test drugs were compared to control experiments not employing hyaluronidase. Results: There were no statistical effects on any of the observed measures. Often the effects were opposite to those predicted. Using a likelihood approach, it was calculated that there was strong evidence (log-likelihood ratios from −0.5 to −6.5) to support a null effect over a facilitatory effect. There was no evidence of loss of integrity of mechanoreceptor mechanotransduction mechanisms following hyaluronidase applications. Comparison with Existing Method: The use of hyaluronidase does not facilitate drug access to receptors. Conclusions: In the in vitro sinus hair preparation, the addition of hyaluronidase does not allow easier access to slowly adapting mechanoreceptors within the follicle.
Entropy, 2023
Categorical data analysis of 2 × 2 contingency tables is extremely common, not least because they... more Categorical data analysis of 2 × 2 contingency tables is extremely common, not least because they provide odds and risk ratio statistics in medical research. The χ 2 test is most often used, although some researchers use the likelihood ratio test (LRT). Does it matter which test is used? This paper argues that the LRT rather than the χ 2 test should be used when we are interested in testing whether two variables are independent, as is typically the case. In contrast, the χ 2 test should be reserved for where the data appear to match too closely a particular hypothesis (e.g. the null hypothesis), as may occur in the investigation of data integrity. Finally, it is argued that the evidential approach provides a consistent and coherent way in which tests can be made for each of these situations.
SSRN Electronic Journal
Introduction: slowly adapting mechanoreceptors in the skin provide vital tactile information to a... more Introduction: slowly adapting mechanoreceptors in the skin provide vital tactile information to animals. The ionic channels that underlie their functioning is the subject of intense research. Previous work suggests that potassium channels may play particular roles in the activation and firing of these mechanoreceptors. Objective: We used a range of potassium channel blockers and openers to observe their effects on different phases of mechanoreceptor responses. Methods: Extracellular recording of neural activity of slowly adapting mechanoreceptors was carried out in an in vitro preparation of the sinus hair follicles taken from rat whisker pads. A range of potassium (K +) channel modulators were tested on these mechanoreceptor responses. The channel blockers tested were: tetraethylammonium (TEA), barium chloride (BaCl 2), dequalinium, 4-aminopyridine (4-AP), paxilline, XE 991, apamin, and charybdotoxin. Results: Except for charybdotoxin and apamin, these drugs increased the activity of both types of slowly adapting units, St I and St II. Generally, both spontaneous and evoked (dynamic and static) activities increased. The channel opener NS1619 was also tested. NS1619 clearly decreased evoked activity (both dynamic and static) while leaving spontaneous activity relatively unaffected, with no clear discrimination of effects on the two types of St receptor Conclusion: These findings are consistent with the targets of the drugs suggesting that K + channels play an important role in the maintenance of spontaneous firing and in the production of and persistence of mechanoreceptor activity.
R Journal, 2022
The likelihoodR package has been developed to allow users to obtain statistics according to the l... more The likelihoodR package has been developed to allow users to obtain statistics according to the likelihood approach to statistical inference. Commonly used tests are available in the package, such as: t tests, ANOVA, correlation, regression and a range of categorical analyses. In addition, there is a sample size calculator for t tests, based upon the concepts of strength of evidence, and the probabilities of misleading and weak evidence.
Comprehensive R Archive Network (CRAN), Feb 11, 2023
Description A collection of functions that calculate the log likelihood (support) for a range of ... more Description A collection of functions that calculate the log likelihood (support) for a range of statistical tests. Where possible the likelihood function and likelihood interval for the observed data are displayed. The evidential approach used here is based on the book``Likelihood'' by A.W.F.
Frontiers in Cardiovascular Medicine
IntroductionThrombotic complications of coronavirus disease 2019 (COVID-19) have received conside... more IntroductionThrombotic complications of coronavirus disease 2019 (COVID-19) have received considerable attention. Although numerous conflicting findings have compared escalated thromboprophylaxis doses with a standard dose to prevent thrombosis, there is a paucity of literature comparing clinical outcomes in three different anticoagulation dosing regimens. Thus, we investigated the effectiveness and safety profiles of standard, intermediate, and high-anti-coagulation dosing strategies in COVID-19 critically ill patients.MethodologyThis retrospective multicenter cohort study of intensive care unit (ICU) patients from the period of April 2020 to August 2021 in four Saudi Arabian centers. Inclusion criteria were age ≥ 18 years, diagnosis with severe or critical COVID-19 infection, and receiving prophylactic anticoagulant dose within 24–48 h of ICU admission. The primary endpoint was a composite of thrombotic events, with mortality rate and minor or major bleeding serving as secondary e...
Research in Mathematics, 2022
The evidential approach uses likelihood ratios, typically the natural logarithm of the likelihood... more The evidential approach uses likelihood ratios, typically the natural logarithm of the likelihood ratio representing the amount of evidence for one hypothesis versus another. One of the barriers to using the approach is the unavailability of sample size calculations for commonly used statistical tests. The t test is the most common statistical test used in scientific publications. This paper derives the equations necessary to calculate evidential probabilities and hence the required sample size for different types of t tests. Compared with the conventional Neyman-Pearson approach, the evidential approach requires larger sample sizes. This drawback is countered by the fact that users know the probability for obtaining misleading evidence (strong evidence that points to the wrong hypothesis). Even with small sample sizes, this is quite small (around 0.05) and decreases further with increasing sample sizes. The main challenge faced by the evidential researcher is of obtaining sufficiently strong evidence for or against one of the two specified hypotheses. Like the probability of a Type II error, this probability is large with a small sample size and decreases as the sample size increases. Sample size is estimated by achieving a low probability (e.g. <.1) for the combined probability of misleading and weak evidence.
Saudi Medical Journal, 2021
To examine the awareness level of COVID-19 and to highlight the frequency of myths and misconcept... more To examine the awareness level of COVID-19 and to highlight the frequency of myths and misconceptions among Saudi Arabia's population. Methods: We conducted a cross-sectional study from June 13 to 20, 2020 by distributing a 16-item online Google forms questionnaire among adults)18-65 years old(living in Saudi Arabia. We utilized the convenience sampling. Data analysis was performed using Chi-square and multiple regression analysis on Jamovi. Results: A total of 1436 responses were analyzed with 43.5% males and 56.5% females. Most respondents)89.1%(thought that only the elderly above 60 years old are considered at high risk of contracting COVID-19. Most respondents)86.5%(agreed that people with other health conditions could be more affected by Original Article COVID-19. Approximately 97.2% agreed that wearing a mask and avoiding touching eyes, nose, and mouth with unwashed hands was the leading preventive action. Most participants)99.4%(chose fever as an associated symptom. Respondents from the healthcare sector presented statistically higher scores than those in non-healthcare sectors)p<0.001(. Higher education and higher salary were important predictors of better COVID-19 knowledge. Conclusion: Public health officials need to increase awareness measures on COVID-19 to limit myths and misconceptions and reduce psychological distress associated with it.
Saudi Medical Journal, 2021
Objectives: To examine the awareness level of COVID-19 and to highlight the frequency of myths an... more Objectives: To examine the awareness level of COVID-19 and to highlight the frequency of myths and misconceptions among Saudi Arabia’s population. Methods: We conducted a cross-sectional study from June 13 to 20, 2020 by distributing a 16-item online Google forms questionnaire among adults (18-65 years old) living in Saudi Arabia. We utilized the convenience sampling. Data analysis was performed using Chi-square and multiple regression analysis on Jamovi. Results: A total of 1436 responses were analyzed with 43.5% males and 56.5% females. Most respondents (89.1%) thought that only the elderly above 60 years old are considered at high risk of contracting COVID-19. Most respondents (86.5%) agreed that people with other health conditions could be more affected by COVID-19. Approximately 97.2% agreed that wearing a mask and avoiding touching eyes, nose, and mouth with unwashed hands was the leading preventive action. Most participants (99.4%) chose fever as an associated symptom. Respon...
Provides readers with a comprehensive and thorough guide to the evidential approach in statistics... more Provides readers with a comprehensive and thorough guide to the evidential approach in statistics. The approach uses likelihood ratios, rather than the probabilities used by other statistical inference approaches. The evidential approach is conceptually easier to grasp, and the calculations more straightforward to perform. This book explains how to express data in terms of the strength of statistical evidence for competing hypotheses. The evidential approach is currently underused, despite its mathematical precision and statistical validity. Evidence-Based Statistics is an accessible and practical text filled with examples, illustrations and exercises. Additionally, the companion website complements and expands on the information contained in the book. While the evidential approach is unlikely to replace probability-based methods of statistical inference, it provides a useful addition to any statistician’s “bag of tricks.” In this book: It explains how to calculate statistical evidence for commonly used analyses, in a step-by-step fashion. Analyses include: t tests, ANOVA (one-way, factorial, between- and within-participants, mixed), categorical analyses (binomial, Poisson, McNemar, rate ratio, odds ratio, data that’s ‘too good to be true’, multi-way tables), correlation, regression and nonparametric analyses (one sample, related samples, independent samples, multiple independent samples, permutation and bootstraps). Equations are given for all analyses, and R statistical code provided for many of the analyses. Sample size calculations for evidential probabilities of misleading and weak evidence are explained. Useful techniques, like Matthews’s critical prior interval, Goodman’s Bayes factor, and Armitage’s stopping rule are described. Recommended for undergraduate and graduate students in any field that relies heavily on statistical analysis, as well as active researchers and professionals in those fields, belongs on the bookshelf of anyone who wants to amplify and empower their approach to statistical analysis.
To form a strong grounding in human–related sciences it is essential for students to grasp the fu... more To form a strong grounding in human–related sciences it is essential for students to grasp the fundamental concepts of statistical analysis, rather than simply learning to use statistical software. Although the software is useful, it does not arm a student with the skills necessary to formulate the experimental design and analysis of a research project in later years of study or indeed, if working in research. This textbook deftly covers a topic that many students find difficult. With an engaging and accessible style it provides the necessary background and tools for students to use statistics confidently and creatively in their studies and future career. Key features: Up–to–date methodology, techniques and current examples relevant to the analysis of large data sets, putting statistics in context Strong emphasis on experimental design Clear illustrations throughout that support and clarify the text A companion website with explanations on how to apply learning to related software packages This is an introductory book written for undergraduate biomedical and social science students with a focus on human health, interactions, and disease. It is also useful for graduate students in these areas, and for practitioners requiring a modern refresher.