ASSESSMENT BRIEF
Subject Code and Title PUBH6005: Epidemiology
Assessment Assessment 3: Critical Appraisal
Individual/Group Individual
Learning Outcomes This assessment addresses the following learning outcomes:
1. Assess levels of evidence and make recommendations
2. Interpret data arising from surveillance and research studies, including rates and ratios
3. Understand the difference between association and causation, statistical and public health significance
4. Critically evaluate epidemiological studies, including potential for bias, confounding and chance errors
Submission Due Sunday following the end of week 11 at
11:55pm AEST/AEDT*
Weighting 40%
Total Marks 100 marks
*Please Note: This time is Sydney time (AEST or AEDT). Please convert to your own time zone (eg. Adelaide = 11:25pm).
PUBH6005_Assessment Brief 3 Page 1 of 8
Context:
This assessment requires you to apply the knowledge and skills gained in all the modules to undertake a critical appraisal. You will need to appraise 3 articles of a topic and research question given to you by your facilitator.
1. Search the library database to find three studies that answer your research question. All three studies must be of different study designs. For instance, you could include case control, cohort and RCTs. These studies do not have to prove their hypothesis or agree with each other. Please note that marks will be deducted if all identified papers are of similar study.
2. Critically appraise all three articles you found. Your answers are to be written in the tables provided to you which was based on CASP checklist and other types of checklist.
3. In the table, you are required to answer either “Yes”, “No”, “Unclear”.
4. For each of the answer of “Yes”, “No” or “Unclear”, you will need to provide the “Evidence” that you found in the article to support your answers.
5. For each of the “Evidence”, you will need to critically appraise stating your justification, compare and contrasting or/and providing solution. Please see table for an example of how “evidence” is written.
References: The quality of references used is important. “high quality reference” is defined as articles which are peer-reviewed and published in notable international and national journals. Articles such as newspaper, websites, social media statements, unsolicited articles and non-peer reviewed articles are not of “high quality reference”. You shall Include all the sources you have used within your text and organize them in alphabetical order according to APA 6th edition style. Please see example of the quality and the style of referencing.
Table 3 Cohort study: The predictive and diagnostic accuracy of vascular endothelial growth factor and pentraxin-3 in severe dengue (Low et al., 2018)
Critical appraisal questions Underline your answer
Did the study address a clearly focused issue? Yes/No/Unclear
Evidence: justification, compare and contrasting or/and providing solution
The objective of this study was to evaluate VEGF and PTX-3 as predictive and diagnostic markers in differentiating severe dengue from non-severe dengue. The objective is specific to evaluating the two biomarkers among so many markers mentioned in the pilot study that was conducted before this study. (Low, Gan, & Ho, 2015) The dengue classification (severe and non-severe) was validated, specific and measureable. It was derived from the World Health Organisation dengue guideline. (World Health Organization, 2009) The study also specifically evaluated the predictive and diagnostic accuracy of the two markers.
Critical appraisal questions Underline your answer
Was the cohort recruited in an acceptable Yes/No/Unclear way?
Evidence: justification, compare and contrasting or/and providing solution
The participants were recruited prospectively based on the eligibility criteria. All participants who are 15 years or older, presented only in the first 3 days of illness and a positive NS1 Ag test. However, it was unclear of the definition of the “illness” as it can represent a specific onset of a symptoms or whether it is due to fever. Majority of the existing studies defined the illness begin when patient developed fever. (Ahmed, 2010; Kumar, Gittens-St Hilaire, & Nielsen, 2013; Mahboob et al., 2010) Based on Table 1, we can assume that all patients were recruited based on the fever presented within the first 3 days of illness. Suggestion to the author is to clearly define what is “illness”.
NS1 Ag is a standard diagnostic test but again, most other studies used Dengue IgM as confirmatory method. (Mahboob et al., 2010; Tang et al., 2015; Thein et al., 2014) However, the author justified that Dengue IgM and a more highly accurate RT-PCR was used to double confirm the NS1 Ag positive cases.
Critical appraisal questions Underline your answer Was the exposure accurately measured to Yes/No/Unclear minimise bias?
Evidence: justification, compare and contrasting or/and providing solution
This study did not measure any exposure (environmental, social determinants, etc).
Perhaps, the exposure in this study was not the objective in assessing the biomarkers. The
“exposure” here for this cohort study should be defined as the biomarkers itself. Thus, the
“exposure” is considered accurately measured by the laboratory technique called as
ELISA. (Dussart et al., 2008)
Critical appraisal questions Underline your answer Was the outcome accurately measured to Yes/No/Unclear minimise bias?
PUBH6005_Assessment Brief 3 Page 3 of 8
Evidence: justification, compare and contrasting or/and providing solution
The outcome was the use of clinical dengue classification (World Health Organization, 2012). It was used by the clinician/treating physician to diagnose the patients recruited. The accuracy of the WHO clinical classification is well documented in other study citing that the “severe dengue” category has good sensitivity and specificity. (Alexander et al., 2011)
Critical appraisal questions Underline your answer
Have the authors identified all important confounding factors? Yes/No/Unclear
Evidence: justification, compare and contrasting or/and providing solution
Confounding factors such as age, sex and ethnicity have been identified. There were other confounding factors such pregnancy; patient with autoimmune disorder, haematological disorder, cancer, cardiovascular disease or on long term warfarin and aspirin. These were identified and it was excluded from the analysis. The different days of illness could also affect the biomarker results and thus, this confounding factor has been included into the statistical analysis.
Critical appraisal questions Underline your answer
Have they taken account of the confounding factors in the design and/or analysis? Yes/No/Unclear
Evidence: justification, compare and contrasting or/and providing solution
Confounding factors have been controlled for by exclusion (restricted analysis) and included into the multivariate regression analysis.
However, possible confounding factor that the author has not taken into account was the treatment effect. No analysis on the treatment in regards to the biomarker prediction. Perhaps, future study to evaluate these biomarkers must include the types of treatment. Treatment for dengue are mainly fluid resuscitation and it should be noted down on the different commonly used fluids for resuscitation in dengue. (World Health Organization, 2012)
Critical appraisal questions Underline your answer
Was the follow up of subjects complete enough? Yes/No/Unclear
Evidence: justification, compare and contrasting or/and providing solution
The follow up of the subjects were up to the day of discharge from the hospital or health care facility. This should suffice as the patient recovered and free of the symptoms or complication of the disease. Other studies did not have long follow-up, instead they used cross-sectional study as their study design. This could possibly due to the availability of resources to support the long term follow-up. (Colbert et al., 2007; Mairuhu et al., 2005;
Thein et al., 2014)
Critical appraisal questions Underline your answer
Was the follow up of subjects long enough? Yes/No/Unclear
Evidence: justification, compare and contrasting or/and providing solution
The follow up of the subjects were up to the day of discharge from the hospital or health care facility. It was the maximum duration of the patients can be follow-up. Though some patients might develop another episode of dengue known as secondary dengue, this study has addressed their objective. It will be interesting to have future study that also follow-up even longer period of time to identify sequelae and secondary which is more common in dengue endemic countries/ tropical countries. (Guzmán et al., 2002; Ludolfs, Schilling, Altenschmidt, & Schmitz, 2002) However, this depends on the resources available to conduct such long-term study.
Add additional pages if needed Reference:
Ahmed, M. M. (2010). Clinical profile of dengue fever infection in King Abdul Aziz University Hospital Saudi Arabia. The Journal of Infection in Developing Countries, 4(8).
Alexander, N., Balmaseda, A., Coelho, I. C. B., Dimaano, E., Hien, T. T., Hung, N. T., … on behalf of the European Union, W. H. O. (WHO-T. supported D. S. G. (2011). Multicentre prospective study on dengue classification in four South-east Asian and three Latin American countries. Tropical Medicine &
International Health, 16(8), 936–948. http://doi.org/10.1111/j.1365-3156.2011.02793.x
Colbert, J. A., Gordon, A., Roxelin, R., Silva, S., Silva, J., Rocha, C., & Harris, E. (2007). Ultrasound measurement of gallbladder wall thickening as a diagnostic test and prognostic indicator for severe dengue in pediatric patients. The Pediatric Infectious Disease Journal, 26(9), 850–852. Retrieved from
http://journals.lww.com/pidj/Fulltext/2007/09000/ULTRASOUND_MEASUREMENT_OF_GALLBLADD ER_WALL.18.aspx
Dussart, P., Petit, L., Labeau, B., Bremand, L., Leduc, A., Moua, D., … Baril, L. (2008). Evaluation of two new commercial tests for the diagnosis of acute dengue virus infection using NS1 antigen detection in human serum. PLoS Neglected Tropical Diseases, 2(8), e280. http://doi.org/10.1371/journal.pntd.0000280
Guzmán, M. G., Kourí, G., Valdés, L., Bravo, J., Vázquez, S., & Halstead, S. B. (2002). Enhanced severity of secondary dengue-2 infections: death rates in 1981 and 1997 Cuban outbreaks. Revista Panamericana de
Salud Pública, 11(4), 223–227. http://doi.org/10.1590/S1020-49892002000400003
Kumar, A., Gittens-St Hilaire, M., & Nielsen, A. L. (2013). Epidemiological trends and clinical manifestations of dengue among children in one of the English-speaking Caribbean countries. Transactions of The Royal Society of Tropical Medicine and Hygiene, trt007.
Low, G. K. K., Gan, S.-C., Zainal, N., Naidu, K. D., Amin-Nordin, S., Khoo, C.-S., … Hatta, N. M. (2018). The predictive and diagnostic accuracy of vascular endothelial growth factor and pentraxin-3 in severe dengue.
Pathogens and Global Health, 112(6), 334–341. http://doi.org/10.1080/20477724.2018.1516417
Low, G. K. K., Gan, S. C., & Ho, S. C. (2015). Biomarkers in differentiating clinical dengue cases: A prospective cohort study. Journal of Coastal Life Medicine, 3(12), 967–970.
Ludolfs, D., Schilling, S., Altenschmidt, J., & Schmitz, H. (2002). Serological differentiation of infections with dengue virus serotypes 1 to 4 by using recombinant antigens. Journal of Clinical Microbiology, 40(11), 4317–4320. http://doi.org/10.1128/JCM.40.11.4317-4320.2002
Mahboob, A., Iqbal, Z., Javed, R., Taj, A., Munir, A., & Saleemi, M. A. (2010). Clinical characteristics of patients with dengue fever: Report of 48 patients in 2010. Journal of Ayub Medical College Abbottabad, 22(4), 23– 120. Mairuhu, A. T. A., Peri, G., Setiati, T. E., Hack, C. E., Koraka, P., Soemantri, A., … Mantovani, A. (2005). Elevated plasma levels of the long pentraxin, pentraxin 3, in severe dengue virus infections. Journal of Medical Virology, 76(4), 547–552.
Tang, Y.-L., Chiu, C.-Y., Lin, C.-Y., Huang, C.-H., Chen, Y.-H., Destura, R. V, … Wu, H.-C. (2015).
Establishment and comparison of two different diagnostic platforms for detection of DENV1 NS1 protein.
International Journal of Molecular Sciences, 16(11), 27850–64. http://doi.org/10.3390/ijms161126069
Thein, T., Wansaicheong, G., Gan, V., Dimatatac, F., Go, C., Lye, D., & Leo, Y. (2014). Ultrasound and chest Xray in an adult patient with dengue. In 63rd Annual Meeting of the American Society of Tropical Medicine and Hygiene, ASTMH 2013 (p. 91 (5 SUPPL. 1): 321). New Orleans, LA United States.
World Health Organization. (2009). Dengue guidelines for diagnosis, treatment, prevention and control. (New ed). Geneva, Switzerland: WHO Press.
World Health Organization. (2012). Handbook for clinical management of dengue. Geneva, Switzerland: WHO Press.
Resources for this assignment
Critically appraising INDIVIDUAL articles
Rychetnick, L., Frommer, M., Hawe, P., & Shiell, A. (2002). Criteria for evaluating evidence on public health. Journal of Epidemiology and Community Health, 56, 119-127.
Young, J.M., & Solomon, M.J. (2009). How to critically appraise an article. Nature Clinical Practice Gastroenterology and Hepatology. 6, 82-91.
CASP UK. Critical appraisal skills program checklists (2018). Retrieved from http://www.caspuk.net/#!casp-tools- checklists/c18f8
Thinking about bias
Skelly, A. C., Dettori J. R., & Brodt, E. K. (2012). Assessing bias: the importance of considering confounding. Evidence Based Spine Care Journal, 3(1), 9-12
Note: Please refer to the Academic Writing Guide as available in the Academic Skills section on your Learning Portal

PUBH6005 Assessment 3 Marking Rubric
Assessment
Attributes Unacceptable Poor Functional Proficient Advanced Exceptional
Critical Appraisal Checklist, 30 marks
Table 1:
Checklist is used to appraise the study with supporting evidence and critical appraisal. (30 marks) Fails to answer each question and provide supporting evidence.
Poor critical appraisal.
0 1 2 3 4 5 All questions answered but some supporting evidence. Irrelevant critical appraisal.
6 7 8 9 10 Answered all questions and supporting evidence are relevant.
Acceptable critical appraisal.
11 12 13 14 15 Answered all questions and supporting evidence are relevant with critical appraisal.
16 17 18 19 20 Answered all questions and supporting evidence are relevant with well
developed, some
original critical appraisal.
21 22 23 24 25 Answered all questions and broad-range, high quality supporting evidence with highly developed, original critical appraisal.
26 27 28 29 30
Table 2:
Checklist is used to appraise the study with supporting evidence and critical appraisal. (30 marks)
Fails to answer each question and provide supporting evidence.
Poor critical appraisal.
0 1 2 3 4 5 All questions answered but some supporting evidence. Irrelevant critical appraisal.
6 7 8 9 10 Answered all questions and supporting evidence are relevant.
Acceptable critical appraisal.
11 12 13 14 15 Answered all questions and supporting evidence are relevant with critical appraisal.
16 17 18 19 20 Answered all questions and supporting evidence are relevant with highly developed, some original critical appraisal.
21 22 23 24 25 Answered all questions and broad-range, high quality supporting evidence are relevant with highly developed, original critical appraisal.
26 27 28 29 30
Table 3:
Checklist is used to appraise the study with supporting evidence and critical appraisal. (30 marks)
Fails to answer each question and provide supporting evidence.
Poor critical appraisal.
0 1 2 3 4 5 All questions answered but some supporting evidence. Irrelevant critical appraisal.
6 7 8 9 10 Answered all questions and supporting evidence are relevant.
Acceptable critical appraisal.
11 12 13 14 15 Answered all questions and supporting evidence are relevant with critical appraisal.
16 17 18 19 20 Answered all questions and supporting evidence are relevant with highly developed, some original critical appraisal.
21 22 23 24 25 Answered all questions and broad-range, high quality supporting evidence are relevant with highly developed, original critical appraisal.
26 27 28 29 30
References
(10 marks)
PUBH6005 Lack of referencing.
0 0.5 1 1.5 2 2.5
_Assessment Brief 4 Insufficient referencing or/and gross mistakes in APA 6th Edition style Minimal referencing or/and some mistakes in APA 6th Adequate referencing or/and minimal mistakes in No mistakes in APA 6th Edition style and intext citation.
7.5 8 8.5 No mistakes in APA 6th Edition style and in-text citation.
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and improper in-text citation.
3 3.5 4 Edition style and intext citation.
4.5 5 5.5 APA 6th Edition style and in-text citation.
6 6.5 7 9 9.5 10
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