Read the article in Appendix A “Example of a Randomized Clinical Trial” (Nyamathi et al.,2015), Discuss the following questions related to the article found on ~p. 162 under Critical Appraisal Criteria: 1. Is the type of design used appropriate? Your rationale? 2. What are the threats to internal and external validity? 3. Is the design appropriately linked to the evidence hierarchy? Cite any sources in APA format.
1. Is the type of design used appropriate? Your rationale?
The type of design used in the study is a randomized clinical trial (RCT), which is an appropriate design for the research question being investigated. RCTs are considered the gold standard for evaluating the effectiveness of interventions and are particularly useful when studying the impact of interventions on health outcomes. In this study, the researchers aimed to assess the effects of an intervention program on reducing substance abuse and HIV risk behaviors among homeless youth.
An RCT design is suitable for this study because it allows for the control of confounding factors and provides a rigorous comparison between groups receiving the intervention and control groups. Randomization helps ensure that the groups being compared are similar at baseline, minimizing biases and increasing the internal validity of the study. The researchers randomized 200 participants into either the intervention group or the control group, strengthening the internal validity of their findings.
Furthermore, RCTs also allow for the evaluation of cause-effect relationships between interventions and outcomes. By randomly assigning participants to groups and implementing the intervention program in a standardized and controlled manner, the researchers can confidently attribute any observed effects to the intervention itself. This study successfully utilized an RCT design to investigate the impact of the intervention program on substance abuse and HIV risk behaviors among homeless youth, making it an appropriate choice for the research question at hand.
2. What are the threats to internal and external validity?
Internal validity refers to the extent to which the observed effects in a study can be attributed to the intervention or treatment being investigated. In this RCT, potential threats to internal validity include confounding variables, selection bias, and attrition bias. To minimize the impact of confounding variables, the researchers randomly assigned participants to either the intervention or control group. Randomization helps ensure that the groups are similar at baseline, reducing the likelihood that other factors are responsible for any observed differences in outcomes.
However, selection bias may still be a concern if the randomization process was not properly executed or if there were differences in the characteristics of those who agreed to participate in the study. This could potentially introduce biases that affect the internal validity of the findings. Additionally, attrition bias could arise if participants drop out of the study selectively, potentially affecting the representativeness of the sample and introducing bias.
External validity refers to the generalizability of the study findings beyond the study sample. One potential threat to external validity in this study is the limited sample size and its specific population of homeless youth. It is important to consider whether the findings can be generalized to other populations or contexts. Furthermore, the study was conducted in a specific geographical location, which may limit the generalizability of the findings to other settings.
3. Is the design appropriately linked to the evidence hierarchy?
The study design used in this research, a randomized clinical trial (RCT), is appropriately linked to the evidence hierarchy. RCTs are considered high-level evidence within the hierarchy of evidence-based medicine. They provide the strongest evidence for assessing the effectiveness of interventions.
According to the hierarchy of evidence, RCTs are at the top because they employ random assignment, include control groups, and have a low risk of bias. RCTs allow for a causal relationship between the intervention and outcomes to be established, making them highly valuable in guiding clinical decision-making and policy development.
By conducting an RCT, the researchers followed the highest level of evidence in evaluating the effectiveness of the intervention program for reducing substance abuse and HIV risk behaviors among homeless youth. This strengthens the credibility and applicability of the study findings, making it a robust piece of evidence for informing future interventions and policies in this area.
In conclusion, the type of design used in the study, a randomized clinical trial, is appropriate for the research question being investigated. This design allows for rigorous comparisons between intervention and control groups and enables an assessment of cause-effect relationships. Internal and external validity threats, such as confounding variables and limited generalizability, should be carefully considered. Lastly, the design is appropriately linked to the evidence hierarchy, thereby providing high-level evidence for informing clinical practice and policy-making.