OHSE3620: In the METHODS Section the trial Design was Described as being “an Open-Label: Epidemiology & Environmental Health Assignment, UoN, Singapore

QUESTIONS

1. In the METHODS section the trial design was described as being “an open-label, parallel randomized clinical trial”. Briefly explain the meaning of:

(a) open-label
(b) parallel

(c) randomized

(d) clinical trial

in the context of this description.

2. In the METHODS section it was also reported that the study aim was to evaluate “the efficacy of oral hydroxychloroquine”.

(a) What is the meaning of efficacy?

(b) Besides efficacy what other important effect of the treatments were the investigators looking out for?

3. Study subjects (participants) were randomized “in the cluster”. Explain

(a) what that means

(b) what the more common alternative way of randomizing treatments is (1 mark); and

(c) what was the main reason why cluster randomization was chosen?

4. Why were participants with a “previous diagnosis of COVID-19” excluded from participating in this study? [Hint: Persons who have recovered from an earlier COVID-19 infection might be immune from re-infection.

5. (a) Was the outcome event that the researchers were looking to observe within the 42-days follow-up time a good (desirable) or a bad (undesirable) outcome?

(b) IF the hydroxychloroquine intervention was more effective than the Control (Vitamin C) would you expect the risk of the outcome occurring in the hydroxychloroquine group to be higher or lower than in the Control group?

6. From the information reported in Table 2,

(a) complete the following 2×2 table to estimate the risk difference efficacy of povidone-iodine throat spray compared to Vitamin C for preventing laboratory-confirmed SARS-CoV-2 infection.

(b) Explain the efficacy result in plain English.