Question

Data was reported from a study of the effect of administration of hydroxychloroquine and remdisivir on survival for patients with COVID-19.

Test of Equality over strata

Test	Chi - Sqaure	DF	Pr> Chi-sqaure
Log Rank	2.788	1	0.095
Wilcoxon	3.306	1	0.069
-2Log(LR)	3.948	1	0.047

a) Use the above computer output. Test the hypothesis that the survival rates of patients with COVID-
19 are the same for patients administered with hydroxychloroquine and patients administered with
remdisivir using the log-rank test.
b) Since the primary interest is in detecting differences in survival rates between the two types of drugs
soon after the diagnosis of COVID-19, which is the more appropriate of the two tests listed? Give a
reason.

Answer 1

Result:

Data was reported from a study of the effect of administration of hydroxychloroquine and remdisivir on survival for patients with COVID-19.

Test of Equality over strata

Test	Chi - Sqaure	DF	Pr> Chi-sqaure
Log Rank	2.788	1	0.095
Wilcoxon	3.306	1	0.069
-2Log(LR)	3.948	1	0.047

a) Use the above computer output. Test the hypothesis that the survival rates of patients with COVID-19 are the same for patients administered with hydroxychloroquine and patients administered with remdisivir using the log-rank test.

In log rank test p value 0.095 which is > 0.05 level of significance. Ho is not rejected.Test is not significant. Therefore survival rates of patients with COVID-19 are the same for patients administered with hydroxychloroquine and patients administered with remdisivir

b) Since the primary interest is in detecting differences in survival rates between the two types of drugs soon after the diagnosis of COVID-19, which is the more appropriate of the two tests listed? Give a reason.

Wilcoxon test is more appropriate here.Wilcoxon method gives more weight to deaths at early time points, which makes more sense in this case.The log-rank test gives equal weight to all time points.