The Main Components of a Randomized Control Trial, Article Critique Example

Outline

• Evaluate the extent to which the main components of a randomized control trial are evident in this study.
• Discuss the potential threats to internal and external validity that may have occurred in this study and identify how they were addressed.

Williams, A. Manias, E. Walker. R., & Gorelik, A. (2012). A multifactorial intervention to improve blood pressure control in co-existing diabetes and kidney disease: a feasibility randomized controlled trial. Journal of Advanced Nursing. Blackwell Publishing

• Evaluate the extent to which the main components of a randomized control trial are evident in this study

Randomized controlled trials is defined as ‘quantitative, comparative, controlled experiments’ (Altman & Doré, 1990). Researchers are termed people who investigate two or more samples and strategies in a series of participants who have been randomly selected. Randomized controlled trials (RCT) have been considered the simplest ones to perform employing one of the most effective and revolutionary research tools (Silverman & Chalmers, 1992).

Essentially, in randomized controlled studies samples are selected randomly. Once selected the term participant is used in describing the sample. A misconception often is that participants have to be afflicted with a disease. However, randomized trails are conducted on disease free participants. They include those which test effects of non-medial programs (Silverman & Chalmers, 1992).

The people who design these studies adopt a methodology consistent with controlled randomized research. They are responsible for collecting and analyzing data by employing procedures that are within research protocol. These can vary depending on the particular methodology chosen. Strategies could range from organizing preventive evaluations, preparing subjects for diagnostic testing, adapting screening measures and implementing treatments (Altman & Doré, 1990).

Distinguishing elements embrace measurement and comparing outcomes of two or more clinical techniques. One is called the standard and the other control. An exclusive feature is that it is a comparative intervention. There must be different groups of participants being analyzed randomly in the study. Consequently, the randomized nature limits precise results whereby all research questions cannot be answered (Altman & Doré, 1990).

With reference to the article ‘A multifactorial intervention to improve blood pressure control in co-existing diabetes and kidney disease: feasibility randomized controlled trial’ contain typical feature of the methodology projected. First the researchers explained the sample as being participants who were ‘randomly allocated on a 1:1 basis to one of two groups in a randomized controlled trial: the intervention delivered over 3 months (n = 39) and usual care (n = 41), with followup at 3, 6 and 9 months postintervention. People collecting data and assessing outcomes were blinded to group assignment’ (Williams et.al, 2012).

These specifics indicate that there were two groups called participants. People collecting data was consistent with the research jargon ‘people’ being investigators. Intervention is another jargon relevant to controlled randomized trials. Participants were allocated a code

through, which they were evaluated. The qualitative nature was exemplified in display of data utilizing statistical interpretation such as t-tests (Williams et.al, 2012).

Evidently, all questions cannot be answered when controlled randomized studies due to the random element. A notable departure from the norm in this study lies to shown whereby 12 participants did not meet the inclusion criteria. Also, they tired answering all questions in the conclusion (Williams et.al, 2012).

3. Discuss the potential threats to internal and external validity that may have occurred in this study and identify how they were addressed

Internal validity pertains to the extent, which research findings measure concepts contained in a study, especially, when making inferences are drawn. This study explored a multifactorial intervention to improve blood pressure control in co-existing diabetes and kidney disease. The inference here is that this multifactorial intervention is expected to improve blood pressure control.  In inferences tested by internal validity “cause” always precedes  “effect” as it relates to time, which creates a temporal precedence (Shadish et.al, 2002).

Next premise is that “cause” and “effect” are covariant or co-related. Consequently, no plausible alternative explanations exist theoretically for the observed covariation. It is sometimes called a nonspurious relationship between two variables (Shadish et.al, 2002). Variables here have been identified as multifactorial intervention; blood pressure control; co-existing diabetes and co-existing kidney disease with the dependant variable being multifactorial intervention (Williams et.al, 2012).

Investigators concluded that the ‘study was feasible and statistically significant differences may be determinable in a larger sample to overcome the variability between groups, paying attention to recommendations for further research’ (Williams et.al, 2012). From this assumption the internal validity issue is that these investigators made inferences from, which there were no cause and effect relationships (Williams et.al, 2012).

Randomized control studies do contain elements of internal validity because of the nature of selection. It is randomized and not purposive sampling techniques. Therefore, the internal validity issues pertain to elements of error in sampling, which were vaguely addressed in this study. Explanations were that ‘statistically significant may be determinable in a larger sample to overcome’ (Williams et.al, 2012). Hence, there were no efforts to clearly minimize the selection and allocation biases.

External validity issues are clearly related to generality of the outcomes. Results pertaining to whether the multifactorial intervention had a strong relationships towards improving blood pressure levels in people with co-existing diabetes and kidney disease rests mainly within the sample and controlled groups used in the study. Also, participants in this study lost their group and the investigators did not know to what groups they belonged. As such external validity regarding the accuracy data retrieval process is questionable.

There was some evidence of incomplete reporting in this study which can affect external validity also. Quite a few of the participants could not remember their correct medication and some did not know with at all. Some patients died from subset of groups and their data in the study was incomplete as well.

Precisely, external validity focuses on the ‘extent to which the results of a study can be generalized to other situations and to other people.’ Clearly, randomized studies do not contain elements to allow this generalization feature. Samples are small and specific. In this case it contained participants who were out-patients who were diabetics and were diagnosed with kidney disease.

References

Altman, G., & Doré, J.(1990) Randomization and baseline comparisons in clinical trials. Lancet 335,149-53.

Shadish, W., Cook, T., & Campbell, D. (2002). Experimental and Quasi-Experimental Designs for Generilized Causal Inference. Boston: Houghton Mifflin.

Silverman, W., & Chalmers, I. (1992). Sir Austin Bradford Hill: an appreciation. Controlled Clin Trials, 13, 100-5

Williams, A. Manias, E. Walker, R., & Gorelik, A. (2012). A multifactorial intervention to improve blood pressure control in co-existing diabetes and kidney disease: a feasibility randomized controlled trial. Journal of Advanced Nursing. Blackwell Publishing