We are planning to do a fully remote clinical trial to test an online intervention for depression. We will be using a self-rated PHQ-9 at base-line, post intervention, and 90 days follow-up to test the efficacy of the intervention.
The participants wouldn't know if they are assigned to the experimental or the control group (so it is definitely single-blind). Since there is no investigator who will be assessing the depression severity, there is no source of any human bias there (since double-blind trials are designed to eliminate investigator bias).
I was wondering if this can be called a double-blind study. I have seen other fully remote trials with a similar design but they haven't mentioned the term double-blind anywhere. Considering the fact that it is the gold standard, I am surprised that investigators did not mention it in their paper. That is the source of my confusion.
Any thoughts are welcome. Thanks in advance.