A randomized controlled trial (RCT) was conducted to investigate the efficacy of a novel antipsychotic medication for the treatment of treatment-resistant schizophrenia. The study enrolled 200 participants who were randomly assigned to receive either the novel antipsychotic or a placebo for a duration of 12 weeks. The primary outcome was the change in the Positive and Negative Syndrome Scale (PANSS) total score from baseline to week 12. The results showed a statistically significant greater reduction in PANSS scores in the novel antipsychotic group compared to the placebo group. The following table summarizes the results:
| Group |
Mean PANSS Score Reduction |
Standard Deviation |
| Novel Antipsychotic |
15.2 |
6.3 |
| Placebo |
7.4 |
5.8 |
Which of the following statistical tests would be most appropriate to compare the mean PANSS score reductions between the two groups?
Explanation:
The independent samples t-test is the most appropriate statistical test for comparing the means of two independent groups when the dependent variable is continuous and normally distributed, and when comparing the mean reduction in PANSS scores between the novel antipsychotic and placebo groups. The other options are either for paired data (paired samples t-test), categorical data (chi-square test), multiple groups (ANOVA), or non-parametric data (Mann-Whitney U test), which are not suitable for this specific comparison.
Explanation:
The independent samples t-test is the most appropriate statistical test for comparing the means of two independent groups when the dependent variable is continuous and normally distributed, and when comparing the mean reduction in PANSS scores between the novel antipsychotic and placebo groups. The other options are either for paired data (paired samples t-test), categorical data (chi-square test), multiple groups (ANOVA), or non-parametric data (Mann-Whitney U test), which are not suitable for this specific comparison.
