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Conducting Rigorous Research Seminar Workbook

4 Seminar Three

This session is protected time to work on the planning of your experimental trial and for the write up of your trial protocol. Based on this weeks lecture content you should now be able to add information about the specific control group you plan to use.

4.1 Control Groups

4.1.1 Purpose

  • Baseline for Comparison: The control arm provides a standard against which the experimental intervention can be compared. This ensures that any observed effects can be attributed to the intervention itself rather than other factors.
  • Minimizing Bias: It helps in minimizing bias by ensuring that both groups (intervention and control) are subject to similar conditions except for the treatment being tested. This increases the reliability of the study results.
  • Ethical Approval: Ethical/institutional review boards often require a control arm to evaluate the safety and efficacy of new interventions. Without it, it can be challenging to establish the comparative effectiveness of the experimental treatment.
  • Quantifying Treatment Effects: By comparing outcomes between the intervention and control groups, researchers can quantify the magnitude of the treatment effect and determine whether the intervention offers significant benefits over existing approaches.

4.1.2 Types

  • Placebo Control Group: Participants in this group receive an inactive intervention (placebo) that resembles the experimental treatment but has no therapeutic effect. Placebo controls help to assess the true effect of the intervention by isolating it from the placebo effect and other biases.
  • Active Control Group: Participants in this group receive a standard treatment or an existing intervention instead of the experimental treatment. This allows researchers to compare the new treatment against an established standard of care, helping to determine if the new treatment is superior, inferior, or equivalent.
  • No-Treatment Control Group: Also known as a “waitlist” or “observation-only” control group, participants in this group receive no treatment or intervention during the trial period. This type of control is used when there is no established standard treatment available or when it is ethically acceptable to withhold treatment.
  • Historical Control Group: In this type of control group, data from previous studies or patient records are used as a comparison group. Historical controls are often employed when it is not feasible or ethical to conduct a randomized controlled trial with a contemporary control group.
  • Dose-Response Control Group: In trials evaluating different doses or levels of an intervention, multiple control groups may be used to compare the various doses against each other and against a placebo or standard treatment. This helps determine the optimal dose with the most favorable risk-benefit profile.

4.2 Useful information

SPIRIT guidelines (Table 1):

Staffordshire University Experimental Trial Protocol Template