The Safety and Efficiency of the Coenzyme Q10 in Heart Failure – Clinical Research Example

Download free paperFile format: .doc, available for editing

The paper 'The Safety and Efficiency of the Coenzyme Q10 in Heart Failure' is a well-written example of clinical research. In the recent past, literature in the field of health care has been observed to tremendously increase making it very hard for the health care practitioners to keep up with most of these publications when in practice. The increase has also resulted in vast contradictory research results what has created even more difficulties for the clinicians in ensuring that the clinical practice is solely based on reliable sources of information.

In this case, systematic reviews have been used to create comprehensive and unbiased summaries of the different healthcare topics what has consolidated varied individual studies into a single document. The systematic reviews are created with a notion that they are able to influence the healthcare decisions for they should bear the same rigor as all the initial researches. However, the quality and rigor of the systematic review have been observed to highly depend on the extent of use of the scientific review methods that reduce the risk of bias and error. In this regard, a critique of the systematic research reviews has been perceived significant for ‘ all that glitters is not gold’ and it is important to warn the health practitioners against using any research in the belief that it is of quality for it has been published.

This paper is a critique of a systematic research review of Coenzyme Q10 for heart failure. The relevance of the research problem The general purpose of the study was “ to review the safety and efficiency of the coenzyme Q10 in heart failure” (Madmani et. al, 2014). The study was undertaken following the fact that several studies have in the past associated the Coenzyme Q10 presence with a number of diseases including heart failure.

A clear elaboration on whether the Coenzyme Q10 does contribute to such illnesses was perceived as important in the prevention of cardiovascular disorders such as heart failure that have continued to threaten the population of the world. Currently, cardiovascular diseases have been outlined as the first cause of disease in both America and other regions of the world (Santullli, 2013). The systematic research review in this case not only sought to improve on the nursing practices but also was adding on the available body of knowledge in relation to cardiovascular illnesses.

In this regard, the research question was stated as ‘ does Coenzyme Q10 deficiency result in heart failure in individuals and how can heart failure be prevented’ . Critique of the rigor of the studies used in the Systematic Research Review (SRR) The systematic research review included seven studies that had a total number of 914 participants in which there were no available data specific on clinical events from the randomized trials.

According to Madmani et. al (2014), these studies also involved very small sample sizes. In research, the sample is selected to significantly represent the target population. To construct an adequate sample size, adequate sampling techniques are used by the researcher. Therefore, the sample size is determined through adequate sampling processes by the use of adequate techniques. Nevertheless, the sample size does influence the results of the research study and the applicability of the results from a study. A study with a small sample size has a higher probability of not ascertaining the true effect of variables under investigation and is likely to result in difficulties in generalizability (Button et. al, 2013).

This is because low sample sizes do not contain all characteristics of the greater population hence the observations in the study are biased. In this case, it would be wrong to declare that the user studies in the SRR were thorough enough to make the researcher achieve his main objective. According to Madmani et. al (2014), amongst the seven studies used in the SRR, only one reported on major cardiovascular, mortality, and hospitalization events.

Then how would have the researcher been able to adequately determine how Coenzyme Q10 deficiency contributed to heart failure without proper evidence supporting the study? The pooled data, in this case, was just a ‘ goose chase’ and the researcher could never arrive at any conclusion by use of such studies. Critique the levels of evidence of the studies included in the SRR The data used in the SRR can basically be grouped as Level II-evidence obtained from well-designed Randomized Controlled Trials (RCT). The RCT is often perceived as the highest level of evidence but Burns et. al (2012) warn that not all RCTs are properly conducted and that the results from the RCT should be interpreted carefully.

In this regard, Madmani et. al (2014) stated that “ there were no data on clinical events from the published randomized trials” and that “ none of the included trials considered the quality of life, exercise variables, adverse events as outcome measures” . This is evidence that the RCT in the studies used in the SRR were not properly conducted something that greatly contributed to the failure of making an adequate conclusion. Clarity with which the studies are presented and critiqued The authors did agree that that the studies used in the SRR were inadequate.

In this case, the outlined the number of participants used in the different studies, articulated non-presence of a report on mortality, hospitalization, and cardiovascular events, and revealed how the heterogeneity of the pooled data limited the chances of performing a meta-analysis. Madmani et. al (2014) acknowledged the need to interpret the available results with a lot of caution for what they termed as a “ small number of small studies with a risk of bias” . Overall findings of the studies summarized in the SRR The pooled data from the studies used in the SRR articulated that the use of Coenzyme Q10 did not adequately have an effect on the left ventricular ejection fractions.

In this case, MD was observed to be -2.26 in a 95 percent level of confidence and results fell in an interval of -15.49 to 10.97 with the number being 60 (n=60). Also, the pooled data signified that the use of the Coenzyme Q10 had no clear effect on the exercise capacity.

In this case, the MD was observed to be 12.79 in a confidence interval of 95 percent and a 5 percent level of significance, and results fell in an interval of -140.12 to 165.70 when the number was 85 (n= 85). Further, the pooled data indicated that supplementation did increase the level of Coenzyme Q10 in the blood. In this case, the MD was observed to be 1.46 with the level of confidence set at 95 percent and results fell in an interval of 1.19 to 1.72 when the number was 112 (n=112) (Madmani et. al, 2014). Critiques of the conclusions of the SRR, with implications for current practice and future research The Authors’ conclusion establishes that the objective of the SRR was not achieved since the harms or benefits of the Coenzyme Q10 in heart failure were never established from the pooled data.

The conclusion further summed the reasons why it was not possible to achieve the objectives of the SRR. However, this conclusion is shallow and fails to provide the actual study or studies to be undertaken in the future to provide evidence of whether Coenzyme Q10 contributes to heart failure.

An SRR is written with the objective of providing a comprehensive and unbiased summary of research on a particular topic. In this case, the authors did make a substantial observation that the ‘ supplementation had an effect on the levels of Coenzyme Q10 in the blood’ . Enzymes are particularly involved in varied biochemical reactions in the blood cells and are a part of the energy management system of the heart.

In this regard, the authors could have made a remark that there is a possibility that the Coenzyme Q10 may have an effect on heart failure since supplementation leads to an increase of the level of Coenzyme Q10 in blood. After which the authors would have now gone an extra mile to indicate the kind of future research study they feel would be adequate in availing evidence that would link or detach Coenzyme Q10 to heart failure. Stating that no adequate conclusion can be made on Coenzyme Q10 effect on heart failure even brings more confusion. Conclusion Critiquing a Systematic Research Review appraises the strengths and weaknesses of the work by an author or a group of authors and further weighs the credibility and applicability of the review to the nursing practice.

In this case, the critiquing was not a criticism of the ability of the authors or the researchers to the studies used in the SRR but an impersonal evaluation of the strengths and weaknesses of the SRR made by the author(s).


Burns, P, B., Rohrich, R, J and Chung, K, C. (2012). The Levels of Evidence and their role in Evidence-Based Medicine, Plast Reconstr Surg, 128(1): 305–310.

Button, K., S, Ioannidis, J., P, Mokrysz, C., Nosek, B., A, Flint, J., Robinson, E., S., Munafo, M., R. (2013). Power failure: why small sample size undermines the reliability of neuroscience. Nat Rev Neurosci, 14(5):365-76.

Madmani M., E., Yusuf, Solaiman, A., Tamr, Agha, K., Madmani, Y., Shahrour. Y., Essali, A., Kadro, W. (2014). Coenzyme Q10 for heart failure (Review). The Cochrane Library, 6.

Santulli, G. (2013). Epidemiology of Cardiovascular Disease in the 21st Century: Updated Numbers and Updated Facts. Journal of Cardiovascular Disease, 1(1).

Download free paperFile format: .doc, available for editing
Contact Us