Hi,

Since there is no intervention or control and only observation, it is a cohort observational study.

Is this a phase IV, surveillance study?

Hi Mariia Gultiaeva could you please elaborate this line in your description "I am going to only control they are taken". How would you control. Does it mean you follow up medication adherence of patients. Does it mean you would use a cutoff such as who take recommended medicine regularly is 1 and 0 otherwise. This is only for my clarification.

If you want to study patient’s compliance to dialysis treatment and the study do not contain any experiment or intervention methods, then I suggest a cohort observational study which is an analytic study design. As I understand it, you want to identify and evaluate if the meds are taken and maybe causes for not being compliant. If you simply want to “observe” this study design is appropriate. If you want to involve the safety surveillance of the dialysis drug or test interactions with other drugs, or if you want to detect rare or long-term adverse effects over a larger patient population and longer time period than possible during the Phase I-III, then a Phase IV trial is applicable.

Thanks everyone! Your answers were very helpful.

Bhogaraju Anand no, I am focusing on some chronic drugs dialysability in actual clinical settings.

Proloy Barua what I meant is that I am not going to provide meds myself, patients have been already taking them for a long time. I just want to emphasize with them that it will be necessary to take their meds regularly as prescribed before their bloods will be sent off to lab.

Tove Godskesen Currently, I am not looking into effects of noncompliance or reasons behind it. I am just looking into dialysability of some meds that patients have been prescribed with by their consultants and that have been taken for a period of time (mostly, years).

Clinical trial

I agree with Tove Godskesen, Proloy and Bhogaraju Anand. You could set a cohort analític study. You have one exposition ( take medications) and several possible outcomes. However, and according to your main outcome ( clearance of some medicines on dialysis ), you could also set a case-control Study. You would have one outcome and several possible expositions ( taking or no taking medications). Likewise, you have to consider limitations of CyC design in order to interpreta the results.

Dear Mariia Gultiaeva,

Here you are not in a position to introduce any exposure (intervention). However you are planning to observe what will happen on your participants who were exposed previously. Thus it seems prospective cohort.

Prospective observational study