Critical Appraisal of Research Literature: Methods

CRITICAL APPRAISAL OF RESEARCH LITERATUREByInstitution
Critical Appraisal of Research Literature
Randomized controlled trials involve a research study using several subjects randomly selected, to provide results for a specific behaviour against a controlled group. The method of reporting randomized controlled trial is useful for assessing a study dealing with healthcare interventions and requires methodological rigor to avoid bias. According to Schulz, Altman and Moher (2010), readers of these studies require clear and transparent information on the findings and methodologies of these studies, which have to address all the critical areas. Randomization provides significant usefulness in prevention of bias in qualitative studies (Viera & Bangdiwala, 2007). However, there exists several biases that randomization fails to prevent, especially in the execution and analysis of the trials (Toggerson & Toggerson, 2003). The CONSORT (Consolidated Standards of Reporting Trials) statement of 2010 provides authors with a checklist of 25 items to ensure the report addresses all pertinent areas (CONSORT, 2010).
Time and Abstract
The authors of Randomized controlled trial of four commercial weight loss programs in the UK: initial findings from the BBC “diet trials” have clearly identified their study as a randomized controlled trial in the given title. The study also contains a brief summary of the study’s objective, design, setting, interventions, outcome measures, results, and conclusions. However, the study lacks a brief description of the methodology as required in the CONSORT 2010 tool. It is important for authors to follow all design procedures to meet quality requirements that the study aims to achieve (Juni, Altman & Eger, 2001). However, the information given by the authors clearly describes their intentions and the results of the trials.
Introduction
The authors gave the intention of their studies reverting to a reported and studied trend in the medical industry where the cost of treating obese people by the National Health Service in the United Kingdom is rising, costing £0.5 billion per year and £2 billion to the economy. Despite the existence of diet trends in the US and UK, conformity to the diet requirements is poor in these countries, with people regaining 50% of their lost weights within a year (Truby et al. 2006). The authors show how the commercial sector has resorted to benefit from this scenario. The Weight Watchers has a million members while the Dr. Atkins New Revolution diet book is a best seller.
The background information given by the authors is shallow and lacking in scientific depth. The study does not cover the real prevalence of the problem (obesity) and the effect it causes to the community in terms of health concern. Additionally, the authors fail to provide the hypotheses for the study though the objective is sufficiently covered. The researchers compared the health outcomes of their participants over six months using four commercial diet programs in the UK namely Slim Fast Plan, Weight Watchers, Dr. Atkin’s New Diet Revolution and Rosemary Conley’s eat yourself diet (Truby et al. 2006).
Methods
The researchers reportedly designed the trial as “unblinded randomized controlled parallel dietary intervention study with a delayed treatment control group” (Truby et al. 2006). Blinding trials assist in averting preferentiality to a specific group and preserves against differences in responses among groups (Juni, Altman & Eger, 2001). By blinding participants and assessors, the researchers can easily prevent them from dictating the outcome of the study, perpetuated by their strong predisposition towards the results of the study (Hróbjartsson et al., 2012; Miller & Stewart, 2010). Therefore, using unbiased trial in this study could have allowed differential treatment of the participants in the groups, leading to biased outcomes (Karanicolas et al. 2010). The researchers conducted the study in five regional centres named as Bristol University, Surrey University, Ulster University, Queen Margaret University, and Nottingham University (Truby et al. 2006). This provided an opportunity to compare similarity of the results, as regional diversity provided little room for bias.
The recruitment of participants involved contacting volunteers identified via BBC advertising. The participants lived around 30 miles from test centres, were of 18-65 years old and had a BMI of 27-40 (Truby et al. 2006). The researchers excluded participants suffering from chronic diseases and other conditions that could prevent adherence to diet or deviate the outcomes. However, the use of assessors to assist participants in matters concerning their eligibility provided an opportunity for selection bias. However, allocation of the participants into random groups is important in safeguarding concealment and masking (Giraudeau & Ravaud, 2009). According to a study done by Walsh and Sheridan in 2016, personal factors such as benefits of the study and health may affect the outcome of the study among participants. It was therefore important for the researchers to consider such factors.
The research allocated 60 participants per group randomly, while allowing for a 25% dropout rate. The participants took baseline tests and began study after six weeks of beginning date. The interventions accorded for each group included allowing participants attend suitable classes in the Weight Watchers and Rosemary Conley’s group and reimbursing them with transport. The researchers also bound the companies providing these services by contracts to ensure they provide quality services (Truby et al., 2006). Members of Slim Fast received a copy of the Slim Fast support pack in addition to the cost of two meals replacement daily, while participant in the Dr. Atkins group received a copy of the Dr. Atkins New Diet Revolution (Truby et al. 2006). Morton (2008) suggests that, providing assistance to participants in research studies is important, as the idea of getting benefits from the study motivates participants and may provide better responses and commitment.
To measure primary outcomes, the researchers took the participants’ weight, waist circumference, height, blood pressure, body fat, and fasting blood at baseline, at two months and six months (Truby et al., 2006). Secondary measurements included monitoring renal function of participants in the Dr. Atkins group. Changes realised after trial commencement was participants in Dr. Atkins group not using mineral supplements as advised in the study maybe due to affordability, forcing the researchers to provide them with the supplements free. The study employed a sample size of 300 participants, which is convenient for a randomized trial. The researchers stratified the participants according to gender but did not provide the method of randomization.
The researchers used Analysis of Variance (ANOVA) to determine the effects of test centres on participants, and weight, differences between groups. Other methods included Tukey’s HSD for “post hoc pair wise testing”, Levine’s statistics for assessing homogeneity of variance, and Wel...