Understanding Clinical Research: Behind the Statistics, All Quiz Answers with Assignments.


Understanding Clinical Research: Behind the                               Statistics

Week 4 Assignment:

Using PubMed, search for an article where statistical methods are used. Post the URL of the selected article.

Important: Please make sure the article you are using is freely available.

I will provide guiding examples of what I would like you to do here, using the article I provided in Case Study 3 in Week 5


Enter title of article.

My example article’s title is: Prevalence and Characteristics of Hepatitis B Virus (HBV) Coinfection among HIV-Positive Women in South Africa and Botswana.

                           Ketogenic diet for epilepsy treatment

Identify and describe the clinical problem being looked at.

My example article’s clinical problem is: To investigate the evolving burden and characteristics of morbidity and mortality caused by coinfection with HIV-1 and hepatitis B virus (HBV) in sub-Saharan Africa.

In the past few years, alternative and more flexible KD variants have been developed to make the treatment easier and more palatable while reducing side effects and making it available to larger group of refractory epilepsy patients

Identify the type of statistical analysis or tests used. Quote a few phrases or sentences from the article about the analysis.

My example article’s statistical analysis is:

Mann Whitney U test

Fischer's exact test

Confidence Intervals (adjusted Wald test)

“Data were analysed using GraphPad Prism v.6.0f. Fisher’s Exact Test was used to compute significance for categorical variables in 2x2 contingency tables. HIV-1 RNA viral loads and CD4+ T cell counts in HBsAg-positive vs. HBsAg-negative subjects were compared using a Mann Whitney U test. HBsAg seroprevalence was quoted with 95% confidence intervals (CI) calculated by the adjusted Wald test “

Sharma et al.33 conducted a randomized controlled trial in 102 children and adolescents with refractory epilepsy to investigate if the MAD improves seizure control and found this KD variant is significantly more effective in controlling seizures compared to the continuation of AEDs alone. The mean seizure frequency at three months from baseline was significantly less in the diet group than in controls (37.3 vs. 100%, p = 0.003) and similar to other uncontrolled studies of the MAD. The diet was well tolerated and side effects did not require discontinuation of the diet.

Write a short paragraph about how the analysis/ statistical methods used by the researchers helped to answer their research question.

My example article’s statistical evidence is: The statistical tests conducted by the researchers helped them to explore relationships between HIV infection and Hepatitis infections. Using methods such as the Fisher’s Exact test they concluded that their data did not show conclusively that the HIV infected patients had greater vulnerability to Hepatitis infections. “The prevalence of HBsAg was not significantly different between HIV-positive vs. HIV-negative sub-groups (66/950 (6.9%) vs. 6/72 (8.3%); p = 0.6, Fisher’s Exact Test).” They concluded that they did not have enough data/or appropriate data to make a conclusion.

The efficacy of the MAD in adults was evaluated in an open-label study and the data showed that, on average, 27% of adolescents and adults achieved ≥ 50% seizure reduction and 6% became seizure-free35. The diet was slightly more effective in those with higher initial seizure frequencies and in younger adults. The MAD can also be administered to adults with intractable epilepsy and counseling can be done by e-mail in a feasible, safe, and effective manner36.

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