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  1. Article ; Online: On the use of receiver operating characteristic curve analysis to determine the most appropriate p value significance threshold

    Farrokh Habibzadeh

    Journal of Translational Medicine, Vol 22, Iss 1, Pp 1-

    2024  Volume 12

    Abstract: Abstract Background p value is the most common statistic reported in scientific research articles. Choosing the conventional threshold of 0.05 commonly used for the p value in research articles, is unfounded. Many researchers have tried to provide a ... ...

    Abstract Abstract Background p value is the most common statistic reported in scientific research articles. Choosing the conventional threshold of 0.05 commonly used for the p value in research articles, is unfounded. Many researchers have tried to provide a reasonable threshold for the p value; some proposed a lower threshold, eg, 0.005. However, none of the proposals has gained universal acceptance. Using the analogy between the diagnostic tests with continuous results and statistical inference tests of hypothesis, I wish to present a method to calculate the most appropriate p value significance threshold using the receiver operating characteristic curve (ROC) analysis. Results As with diagnostic tests where the most appropriate cut-off values are different depending on the situation, there is no unique cut-off for the p significance threshold. Unlike the previous proposals, which mostly suggest lowering the threshold to a fixed value (eg, from 0.05 to 0.005), the most appropriate p significance threshold proposed here, in most instances, is much less than the conventional cut-off of 0.05 and varies from study to study and from statistical test to test, even within a single study. The proposed method provides the minimum weighted sum of type I and type II errors. Conclusions Given the perplexity involved in using the frequentist statistics in a correct way (dealing with different p significance thresholds, even in a single study), it seems that the p value is no longer a proper statistic to be used in our research; it should be replaced by alternative methods, eg, Bayesian methods.
    Keywords Methods ; Probability ; Data interpretation ; statistical ; Biomedical research ; Medicine ; R
    Subject code 310
    Language English
    Publishing date 2024-01-01T00:00:00Z
    Publisher BMC
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  2. Article ; Online: Correction of vaccine effectiveness derived from test-negative case–control studies

    Farrokh Habibzadeh

    BMC Medical Research Methodology, Vol 23, Iss 1, Pp 1-

    2023  Volume 6

    Abstract: Abstract Background Determining the vaccine effectiveness (VE) is an important part of studying every new vaccine. Test-negative case–control (TNCC) studies have recently been used to determine the VE. However, the estimated VE derived from a TNCC design ...

    Abstract Abstract Background Determining the vaccine effectiveness (VE) is an important part of studying every new vaccine. Test-negative case–control (TNCC) studies have recently been used to determine the VE. However, the estimated VE derived from a TNCC design depends on the test sensitivity and specificity. Herein, a method for correction of the value of VE derived from a TNCC study is presented. Methods An analytical method is presented to compute the corrected VE based on the sensitivity and specificity of the diagnostic test utilized. To show the application of the method proposed, a hypothetical TNCC study is presented. In this in silico study, 100 000 individuals referring to a healthcare system for COVID-19-like illness were tested with diagnostic tests with sensitivities of 0.6, 0.8, and 1.0, and specificities ranging from 0.85 to 1.00. A vaccination coverage of 60%, an attack rate of 0.05 for COVID-19 in unvaccinated group, and a true VE of 0.70, were assumed. In this simulation, a COVID-19-like illness with an attack rate of 0.30 could also affect all the studied population regardless of their vaccination status. Results The observed VE ranged from 0.11 (computed for a test sensitivity of 0.60 and specificity of 0.85) to 0.71 (computed for a test sensitivity and specificity of 1.0). The mean computed corrected VE derived from the proposed method was 0.71 (the standard deviation of 0.02). Conclusions The observed VE derived from TNCC studies can be corrected easily. An acceptable estimate for VE can be computed regardless of the diagnostic test sensitivity and specificity used in the study.
    Keywords Vaccines ; Case–control studies ; Diagnostic tests ; Sensitivity and specificity ; SARS-CoV-2 ; Medicine (General) ; R5-920
    Subject code 150
    Language English
    Publishing date 2023-06-01T00:00:00Z
    Publisher BMC
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  3. Article ; Online: Karim Vessal, MD

    Farrokh Habibzadeh

    Iranian Journal of Medical Sciences, Vol 47, Iss 2, Pp 79-

    2022  Volume 80

    Keywords Medicine (General) ; R5-920
    Language English
    Publishing date 2022-03-01T00:00:00Z
    Publisher Shiraz University of Medical Sciences
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  4. Article ; Online: THE QUEST FOR INDEXING A JOURNAL

    Farrokh Habibzadeh

    Central Asian Journal of Medical Hypotheses and Ethics, Vol 1, Iss 2, Pp 142-

    2021  Volume 145

    Abstract: Hearing about the selection of one’s journal by a reputable indexing system pleases every editor. Journals with an international editorial members selected from prolific researchers have a higher chance of being selected by a prestigious indexing system. ...

    Abstract Hearing about the selection of one’s journal by a reputable indexing system pleases every editor. Journals with an international editorial members selected from prolific researchers have a higher chance of being selected by a prestigious indexing system. Geographic distribution of authors’ affiliations is another important factor. Considering a minimum of internationally acceptable editorial standards would also influence the decision of the indexing systems to select a journal—publishing few quality articles is much better than publishing a bunch of poorly designed badly reported ones. The key to success is having a group of dedicated staff with good communication skills.
    Keywords periodicals as topic ; journalism ; bibliographies as topic ; ethics ; publishing ; medicine ; Medical philosophy. Medical ethics ; R723-726
    Language English
    Publishing date 2021-01-01T00:00:00Z
    Publisher South Kazakhstan Medical Academy
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  5. Article ; Online: The Last Note

    Farrokh Habibzadeh

    The International Journal of Occupational and Environmental Medicine, Vol 11, Iss 4 October, Pp 155-

    2020  Volume 156

    Keywords Industrial medicine. Industrial hygiene ; RC963-969
    Language English
    Publishing date 2020-10-01T00:00:00Z
    Publisher National Iranian Oil Company (NIOC) Health Organization
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  6. Article ; Online: Word War III

    Farrokh Habibzadeh

    The International Journal of Occupational and Environmental Medicine, Vol 11, Iss 3 July, Pp 117-

    2020  Volume 8

    Abstract: No abstract available] ...

    Abstract [No abstract available]
    Keywords covid-19 ; sars-cov-2 ; epidemic ; coronavirus ; Industrial medicine. Industrial hygiene ; RC963-969 ; covid19
    Language English
    Publishing date 2020-07-01T00:00:00Z
    Publisher National Iranian Oil Company (NIOC) Health Organization
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  7. Article ; Online: Tenth Anniversary of The IJOEM

    Farrokh Habibzadeh

    The International Journal of Occupational and Environmental Medicine, Vol 11, Iss 1, Pp 1-

    2020  Volume 2

    Keywords journals ; occupational medicine ; environmental medicine ; Industrial medicine. Industrial hygiene ; RC963-969
    Language English
    Publishing date 2020-01-01T00:00:00Z
    Publisher National Iranian Oil Company (NIOC) Health Organization
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  8. Article ; Online: No need for a gold-standard test

    Farrokh Habibzadeh / Hooman Roozbehi

    BMC Medical Research Methodology, Vol 23, Iss 1, Pp 1-

    on the mining of diagnostic test performance indices merely based on the distribution of the test value

    2023  Volume 8

    Abstract: Abstract Background Diagnostic tests are important in clinical medicine. To determine the test performance indices — test sensitivity, specificity, likelihood ratio, predictive values, etc. — the test results should be compared against a gold-standard ... ...

    Abstract Abstract Background Diagnostic tests are important in clinical medicine. To determine the test performance indices — test sensitivity, specificity, likelihood ratio, predictive values, etc. — the test results should be compared against a gold-standard test. Herein, a technique is presented through which the aforementioned indices can be computed merely based on the shape of the probability distribution of the test results, presuming an educated guess. Methods We present the application of the technique to the probability distribution of hepatitis B surface antigen measured in a group of people in Shiraz, southern Iran. We assumed that the distribution had two latent subpopulations — one for those without the disease, and another for those with the disease. We used a nonlinear curve fitting technique to figure out the parameters of these two latent populations based on which we calculated the performance indices. Results The model could explain > 99% of the variance observed. The results were in good agreement with those obtained from other studies. Conclusion We concluded that if we have an appropriate educated guess about the distributions of test results in the population with and without the disease, we may harvest the test performance indices merely based on the probability distribution of the test value without need for a gold standard. The method is particularly suitable for conditions where there is no gold standard or the gold standard is not readily available.
    Keywords Diagnostic test ; Data mining ; Statistical methods ; Biomarkers ; Classification and taxonomy ; Hepatitis ; Medicine (General) ; R5-920
    Subject code 310
    Language English
    Publishing date 2023-01-01T00:00:00Z
    Publisher BMC
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  9. Article ; Online: What's Up?

    Farrokh Habibzadeh

    The International Journal of Occupational and Environmental Medicine, Vol 10, Iss 2, Pp 53-

    2019  Volume 53

    Abstract: No abstract available] ...

    Abstract [No abstract available]
    Keywords Altmetrics ; Archiving systems ; Respository ; Industrial medicine. Industrial hygiene ; RC963-969
    Language English
    Publishing date 2019-04-01T00:00:00Z
    Publisher National Iranian Oil Company (NIOC) Health Organization
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  10. Article ; Online: The IJOEM, DOAJ Seal, and Plan S

    Farrokh Habibzadeh

    The International Journal of Occupational and Environmental Medicine, Vol 10, Iss 4, Pp 157-

    2019  Volume 158

    Abstract: No abstract available] ...

    Abstract [No abstract available]
    Keywords Open access ; Plan S ; Journalism ; Industrial medicine. Industrial hygiene ; RC963-969
    Language English
    Publishing date 2019-10-01T00:00:00Z
    Publisher National Iranian Oil Company (NIOC) Health Organization
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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