1.Comprehensive guidelines for appropriate statistical analysis methods in research
Jonghae KIM ; Dong Hyuck KIM ; Sang Gyu KWAK
Korean Journal of Anesthesiology 2024;77(5):503-517
Background:
The selection of statistical analysis methods in research is a critical and nuanced task that requires a scientific and rational approach. Aligning the chosen method with the specifics of the research design and hypothesis is paramount, as it can significantly impact the reliability and quality of the research outcomes.
Methods:
This study explores a comprehensive guideline for systematically choosing appropriate statistical analysis methods, with a particular focus on the statistical hypothesis testing stage and categorization of variables. By providing a detailed examination of these aspects, this study aims to provide researchers with a solid foundation for informed methodological decision making. Moving beyond theoretical considerations, this study delves into the practical realm by examining the null and alternative hypotheses tailored to specific statistical methods of analysis. The dynamic relationship between these hypotheses and statistical methods is thoroughly explored, and a carefully crafted flowchart for selecting the statistical analysis method is proposed.
Results:
Based on the flowchart, we examined whether exemplary research papers appropriately used statistical methods that align with the variables chosen and hypotheses built for the research. This iterative process ensures the adaptability and relevance of this flowchart across diverse research contexts, contributing to both theoretical insights and tangible tools for methodological decision-making.
Conclusions
This study emphasizes the importance of a scientific and rational approach for the selection of statistical analysis methods. By providing comprehensive guidelines, insights into the null and alternative hypotheses, and a practical flowchart, this study aims to empower researchers and enhance the overall quality and reliability of scientific studies.
2.The principles of presenting statistical results using figures
Jae Hong PARK ; Dong Kyu LEE ; Hyun KANG ; Jong Hae KIM ; Francis Sahngun NAHM ; EunJin AHN ; Junyong IN ; Sang Gyu KWAK ; Chi-Yeon LIM
Korean Journal of Anesthesiology 2022;75(2):139-150
Tables and figures are commonly adopted methods for presenting specific data or statistical analysis results. Figures can be used to display characteristics and distributions of data, allowing for intuitive understanding through visualization and thus making it easier to interpret the statistical results. To maximize the positive aspects of figure presentation and increase the accuracy of the content, in this article, the authors will describe how to choose an appropriate figure type and the necessary components to include. Additionally, this article includes examples of figures that are commonly used in research and their essential components using virtual data.
3.The principles of presenting statistical results: Table
Sang Gyu KWAK ; Hyun KANG ; Jong Hae KIM ; Tae Kyun KIM ; EunJin AHN ; Dong Kyu LEE ; Sangseok LEE ; Jae Hong PARK ; Francis Sahngun NAHM ; Junyong IN
Korean Journal of Anesthesiology 2021;74(2):115-119
General medical journals such as the Korean Journal of Anesthesiology (KJA) receive numerous manuscripts every year. However, reviewers have noticed that the tables presented in various manuscripts have great diversity in their appearance, resulting in difficulties in the review and publication process. It might be due to the lack of clear written instructions regarding reporting of statistical results for authors. Therefore, the present article aims to briefly outline reporting methods for several table types, which are commonly used to present statistical results. We hope this article will serve as a guideline for reviewers as well as for authors, who wish to submit a manuscript to the KJA.
4.The principles of presenting statistical results: Table
Sang Gyu KWAK ; Hyun KANG ; Jong Hae KIM ; Tae Kyun KIM ; EunJin AHN ; Dong Kyu LEE ; Sangseok LEE ; Jae Hong PARK ; Francis Sahngun NAHM ; Junyong IN
Korean Journal of Anesthesiology 2021;74(2):115-119
General medical journals such as the Korean Journal of Anesthesiology (KJA) receive numerous manuscripts every year. However, reviewers have noticed that the tables presented in various manuscripts have great diversity in their appearance, resulting in difficulties in the review and publication process. It might be due to the lack of clear written instructions regarding reporting of statistical results for authors. Therefore, the present article aims to briefly outline reporting methods for several table types, which are commonly used to present statistical results. We hope this article will serve as a guideline for reviewers as well as for authors, who wish to submit a manuscript to the KJA.
5.Short-Term Walking Outcomes in Diabetic and Non-Diabetic Unilateral Transtibial Amputees
Dong Gyu KWAK ; Jeong-Yong HUR ; Jun Sung MOON ; Min Cheol CHANG
Diabetes & Metabolism Journal 2020;44(4):614-618
This study compared short-term walking outcomes in diabetic amputees after prosthesis fitting compared to that in non-diabetic amputees. We retrospectively investigated walking outcomes at 3 months after starting gait training with a prosthesis. Forty-four unilateral transtibial amputees with (
6.Sequential Activation of AMPA Receptors and Glial Cells in a Pain Model of Lumbar Spine Disc Herniation
Annals of Rehabilitation Medicine 2020;44(5):343-352
Objective:
To investigate the glial cell and AMPA (alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid) receptor activity after surgery for disc herniation pain model.
Methods:
In total, 83 Sprague-Dawley rats were randomly assigned to the following groups: control (n=16), sham-operated (n=4), rats for pain behavior evaluation (n=3), nucleus pulposus-exposed groups for AMPA receptors (n=30), and glial cell (n=30). The rats were tested for mechanical allodynia; immunohistochemical staining for AMPA receptors (GluA1 and GluA2) and glial cells (OX-42 and glial fibrillary acid protein [GFAP]) in the spinal dorsal horn was performed on postoperative days 3, 7, and 14.
Results:
Mechanical withdrawal thresholds decreased after surgery, and this effect was maintained for up to 14 days. Immunohistochemical expression of GluA1 and GluA2 in the spinal dorsal horn had increased quantitatively on postoperative days 3 and 7 (p<0.05) to levels similar to that of the controls on postoperative day 14. Moreover, immunohistochemical expression of OX-42 and GFAP showed similar changes to AMPA receptors after surgery. Although the activity of AMPA receptors and glial cells achieved normalcy, the mechanical withdrawal threshold of the hind paw remained decreased 38 days after surgery.
Conclusion
The rat model of lumbar disc herniation showed increased expression of AMPA receptor and glial cell activity in the spinal dorsal horn 3 and 7 days after surgery, which deceased to control levels at 14 days. The AMPA receptors and glial cell activations showed similar patterns after disc herniation surgery.
7.Long-term benefits of chest compression-only cardiopulmonary resuscitation training using real-time visual feedback manikins: a randomized simulation study
Tae Chang JANG ; Hyun Wook RYOO ; Sungbae MOON ; Jae Yun AHN ; Dong Eun LEE ; Won Kee LEE ; Sang Gyu KWAK ; Jung Ho KIM
Clinical and Experimental Emergency Medicine 2020;7(3):206-212
Objective:
Cardiopulmonary resuscitation (CPR) education with a feedback device is known to result in better CPR skills compared to one without the feedback device. However, its long-term benefits have not been established. The purpose of this study was to evaluate the long-term CPR skill retention after training using real-time visual manikins in comparison to that of non-feedback manikins.
Methods:
We recruited 120 general university students who were randomly divided into the real-time feedback group (RTFG) and the non-feedback group. Of them, 95 (RTFG, 48; non-feedback group, 47) attended basic life support and automated external defibrillation training for 1 hour. For comparison of retention of CPR skills, the two groups were evaluated based on 2-minute chest compression performed immediately after training and at 3, 6, and 9 months. The CPR parameters between the two groups were also compared using a generalized linear model.
Results:
At immediately after training, the performance of RTFG was better in terms of average chest compression depth (51.9±1.1 vs. 45.5±1.1, p<0.001) and a higher percentage of adequate chest compression depth (51.0±4.1 vs. 26.9±4.2, p<0.001). This significant difference was maintained until 6 months after training, but there was no difference at 9 months after training. However, there was no significant difference in the chest compression rate and the correct hand position at any time point.
Conclusion
CPR training with a real-time visual feedback manikin improved skill acquisition in chest compression depth, but only until 6 months after the training. It could be a more effective educational method for basic life support training in laypersons.
8.Development of a Pancreatic Cancer Specific Binding Peptide Using Phage Display
Dong Won LEE ; Jae Myung PARK ; Seung Mok YANG ; Moon Hwa KWAK ; Yoon Jin ROH ; In Seok LEE ; Myung Gyu CHOI
The Korean Journal of Gastroenterology 2019;74(1):30-41
BACKGROUND/AIMS: Pancreatic cancer has a very poor prognosis, and early diagnosis is a way to increase the survival rate of patients. The purpose of this study was to develop pancreatic cancer-specific peptides for imaging studies. METHODS: Three pancreatic cancer cell lines, MIA PaCa-2, UACC-462, and BxPC-3, and a control cell line, CCD841, were used. Biopannings were performed on MIA PaCa-2 using a phage display library. After this, the peptides were synthesized and labeled with fluorescein isothiocyanate (FITC). Immunocytochemistry (ICC), enzyme-linked immunosorbent assay (ELISA), and fluorescence-activated cell sorter (FACS) were performed to examine the specific binding. To examine its therapeutic applications, a photosensitizer, chlorin e6 (Ce6), was conjugated on the peptide and photodynamic therapy was performed. Cell survival was investigated using a [3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide] assay. RESULTS: After three biopannings, the phages were amplified from 1.4×104 to 3.2×105 plaque-forming units. The most strongly binding phage was selected from the ELISA and ICC results. FITC-labeled peptide, M5, in the three pancreatic cancer cell lines showed significantly higher immunofluorescence in the ICC experiments than that of CCD841. The higher binding ability to MIA PaCa-2 cells was confirmed from FACS analysis, which showed a right shift compared to CCD841. M5 bound to Ce6 showed a significantly lower cell survival rate than that of Ce6 alone in photodynamic therapy, which was observed consistently as a change in the tumor size and fluorescence intensity in MIA PaCa-2 cell-implanted animal models. CONCLUSIONS: This study showed that the noble peptide, M5, binds specifically to the pancreatic cancer cell line, MIA PaCa-2. The M5 peptide has potential use in future optical diagnostic and therapeutic purposes.
Bacteriophages
;
Cell Line
;
Cell Survival
;
Early Diagnosis
;
Enzyme-Linked Immunosorbent Assay
;
Fluorescein
;
Fluorescence
;
Fluorescent Antibody Technique
;
Humans
;
Immunohistochemistry
;
Models, Animal
;
Pancreatic Neoplasms
;
Peptides
;
Photochemotherapy
;
Prognosis
;
Survival Rate
9.Development of a Pancreatic Cancer Specific Binding Peptide Using Phage Display
Dong Won LEE ; Jae Myung PARK ; Seung Mok YANG ; Moon Hwa KWAK ; Yoon Jin ROH ; In Seok LEE ; Myung Gyu CHOI
The Korean Journal of Gastroenterology 2019;74(1):30-41
BACKGROUND/AIMS: Pancreatic cancer has a very poor prognosis, and early diagnosis is a way to increase the survival rate of patients. The purpose of this study was to develop pancreatic cancer-specific peptides for imaging studies.METHODS: Three pancreatic cancer cell lines, MIA PaCa-2, UACC-462, and BxPC-3, and a control cell line, CCD841, were used. Biopannings were performed on MIA PaCa-2 using a phage display library. After this, the peptides were synthesized and labeled with fluorescein isothiocyanate (FITC). Immunocytochemistry (ICC), enzyme-linked immunosorbent assay (ELISA), and fluorescence-activated cell sorter (FACS) were performed to examine the specific binding. To examine its therapeutic applications, a photosensitizer, chlorin e6 (Ce6), was conjugated on the peptide and photodynamic therapy was performed. Cell survival was investigated using a [3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide] assay.RESULTS: After three biopannings, the phages were amplified from 1.4×104 to 3.2×105 plaque-forming units. The most strongly binding phage was selected from the ELISA and ICC results. FITC-labeled peptide, M5, in the three pancreatic cancer cell lines showed significantly higher immunofluorescence in the ICC experiments than that of CCD841. The higher binding ability to MIA PaCa-2 cells was confirmed from FACS analysis, which showed a right shift compared to CCD841. M5 bound to Ce6 showed a significantly lower cell survival rate than that of Ce6 alone in photodynamic therapy, which was observed consistently as a change in the tumor size and fluorescence intensity in MIA PaCa-2 cell-implanted animal models.CONCLUSIONS: This study showed that the noble peptide, M5, binds specifically to the pancreatic cancer cell line, MIA PaCa-2. The M5 peptide has potential use in future optical diagnostic and therapeutic purposes.
Bacteriophages
;
Cell Line
;
Cell Survival
;
Early Diagnosis
;
Enzyme-Linked Immunosorbent Assay
;
Fluorescein
;
Fluorescence
;
Fluorescent Antibody Technique
;
Humans
;
Immunohistochemistry
;
Models, Animal
;
Pancreatic Neoplasms
;
Peptides
;
Photochemotherapy
;
Prognosis
;
Survival Rate
10.Influence of Nasogastric Tubes on Swallowing in Stroke Patients: Measuring Hyoid Bone Movement With Ultrasonography.
Ho Jun KWAK ; Lina KIM ; Byung Ju RYU ; Yun Hee KIM ; Seung Wan PARK ; Dong Gyu CHO ; Cheol Jae LEE ; Kang Wook HA
Annals of Rehabilitation Medicine 2018;42(4):551-559
OBJECTIVE: To investigate the influence of a nasogastric tube (NGT) on swallowing simulated saliva in stroke patients. METHODS: Three groups of participants were enrolled into the study: group A (20 stroke patients with a NGT), a control group B (25 stroke patients without a NGT), and group C (25 healthy adults with no brain lesions or dysphagia). Participants swallowed 1 mL of water to simulate saliva. Patients in group A were tested twice: once with a NGT (group A1) and once after the NGT was removed (group A2). The distance of hyoid bone movement was measured by subtracting the shortest distance between the mandible and hyoid bone (S) from the distance at resting state (R) measured with ultrasonography. The degree of the movement was calculated by (R–S)/R. The trajectory area of hyoid bone movement (Area) and the interval between the beginning of hyoid bone movement and the moment of the shortest hyoid−mandible approximation (Interval) was calculated by a computer program. RESULTS: From group A: R–S and (R–S)/R of group A2 at 1.14±0.36 cm and 0.30±0.09 cm and were significantly greater than those of group A1 at 0.81±0.36 cm and 0.22±0.08 cm (p=0.009 and p=0.005). After removing the NGT as seen in group A2, R–S and (R–S)/R were improved to the level of those of group B at 1.20±0.32 cm and 0.30±0.09 cm (p=0.909 and p=0.997). The Area of group A2 was larger and the Interval of group A2 was shorter than those of group A1 though a comparison of these factors between A2 and A1 did not show a statistically significant difference. CONCLUSION: A NGT interferes with the movement of the hyoid bone when swallowing 1 mL of water in stroke patients though the movement is restored to normal after removing the NGT.
Adult
;
Brain
;
Deglutition Disorders
;
Deglutition*
;
Humans
;
Hyoid Bone*
;
Mandible
;
Saliva
;
Stroke*
;
Ultrasonography*
;
Water

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