Question 20

Blind study eliminates bias related to patient awareness of placebo.

A blind study ensures that patients are unaware of whether they are receiving the treatment or a placebo, thereby minimizing any bias that might arise from their expectations or perceptions about the treatment's effectiveness.

A) Blind study

This option is correct because a blind study minimizes bias by keeping patients in the dark about their treatment allocation. By not knowing if they are receiving the actual drug or a placebo, patients' responses are less likely to be influenced by their expectations or beliefs about the treatment.

B) Time series study

A time series study observes changes over time but does not control for bias related to patient awareness of treatment allocation. Since patients may still know whether they are receiving a placebo or treatment, this design does not eliminate the potential for bias.

C) Observational study

An observational study involves observing subjects without intervention, which leaves patients aware of their treatment status. This awareness can lead to biases in reporting and behavior, making this option ineffective in eliminating the specific bias related to placebo knowledge.

D) Prospective cohort study

A prospective cohort study tracks subjects over time but does not inherently include blinding. Patients may be aware of their treatment assignment, which can introduce bias in their responses and overall study outcomes, thus making it a less effective choice for eliminating bias related to placebo awareness.

Conclusion

The blind study is definitively the correct answer as it directly addresses the issue of bias from patient awareness, a critical factor in the validity of clinical trial results. Other study designs, such as time series, observational, and prospective cohort studies, do not adequately mitigate this specific type of bias, thereby compromising the integrity of the research findings.