In my previous post I tackled the reasoning behind why we refer to a doctor working in clinical trials as an “investigator”. Today I want to try and explain how working as a clinical investigator in trials is different to working as a doctor / physician / general practitioner.

How is being an investigator different to being a doctor?

I posed this very question in 2019 to some of the doctors at TASK that are appointed in the role of investigator, while busy compiling a course for TASK Academy. Here are some of their replies:

“The heightened emphasis on attention to the smallest of details! Working as a clinical trial investigator involves coordinated interaction with various members of staff, rather than working more in isolation as a doctor in General Practice.” Dr. B. Esterhuizen 

“Currently I work mainly on vaccine trials, therefore essentially healthy participants, whereas in my previous doctor job I dealt with ill individuals. The way of thinking is also different as I am not always searching for a diagnosis (as in GP or hospital work) but rather documenting symptoms or signs that may or may not be related to the investigational product.” Dr. M. Blomeyer  

“I found that the main difference is the amount of time that you spend on good documentation. Trial work involves a lot more administration, but you also have the privilege of spending more time on each patient and often get to look at them more holistically.”  Dr. C. Holmgren         

“Definitely more admin! Very focused approach regarding adverse events (AE’s) and physical examination as well. Stringent adherence to the protocol.” Dr T Govender

To summarise:

  1. You will be part of a clinical trial team
  2. Trial work involves extreme attention to detail
  3. Your work will be highly administrative in nature
  4. You need to put time aside to document accurately and contemporaneously (in “real” time)
  5. You must adhere to good clinical practice (GCP) guidelines and the protocol
  6. You will report on and interpret adverse events

What is the role of the investigator?

I recently read an article published in 2009 by David B Resnik, on the topic “The clinical investigator-subject relationship: a contextual approach” where he suggested the very nature of the relationship between a clinical investigator and the participant has generated considerable debate because the investigator fulfils two distinct roles:

Clinician and scientist 

  • As a clinician, the investigator has duties to provide the participant with optimal care and undivided loyalty.
  • As a scientist, the investigator has duties to follow the rules, good clinical practice (GCP), procedures and methods described in the protocol.

These distinct obligations may sometimes be conflicting when investigators are conducting clinical research.  However, from my experience working alongside clinicians in the role of investigators for many years – if you stick to the main principle of good clinical practice, namely putting participant safety first, the two roles should align.


Protocol: This document describes the objective(s), design, methodology, statistical considerations, as well as how the trial should be conducted and what type of population should be included. The protocol must be approved by the authorities before the trial can start and you need to study the protocol before you can work on the trial and not deviate from it (unless it is for participant safety reasons)

Adverse events (AE’s): From computer modelling to pre-clinical trials, researchers can anticipate potential unwanted effects. To establish clinical safety, a drug needs to be tested in humans to see how well it is tolerated. For this reason, we have clinical trials. During each phase of a clinical trial, safety information is collected and recorded. In a clinical trial all safety information is collected by means of medical history, physical examinations, laboratory results and other suitable means from the first visit (this will be called “baseline”) to the last visit, all the way through the period when an investigational medicine is taken. Any change from baseline is documented, regardless of whether the event occurred because of the investigational product or not. This way a safety profile of the new medicine is built. 

The responsibilities of the investigator (in a nutshell):  ICH-GCP-R2, section 4

  1. Be registered, qualified, trained, and knowledgeable about the protocol, good clinical practice and local / international regulations
  2. Be the team lead – to ensure your facility has the correct equipment, resources, sufficient qualified staff to conduct the study and recruit in time and provide supervision 
  3. Provide medical care to participants
  4. Communicate with regulatory authorities and independent ethics committees by submitting progress reports during the entire lifecycle of your study 
  5. Compliance – with GCP, the protocol and site-and-sponsor policies
  6. Accountability – for the investigational product stored at your site   
  7. Obtain /conduct informed consent 
  8. Maintain records, investigator site files with essential trial documents until archiving 
  9. Report on safety matters to sponsor and regulatory authorities 
  10. Permit monitoring visits and audits / inspections

This might seem like an unreasonable number of responsibilities but remember, you are part of a team and the investigator can delegate tasks to staff, as per their qualification and training, but more about this later!


Karen Cloete

Head Quality Assurance and Regulatory, Founder TASK Academy

With years of hands-on experience and under the leadership of Karen Cloete, TASK Quality and Regulatory team ensures high-quality standard and GCP compliance of all trials conducted at TASK. They also offer consulting services to sponsors and sites – feasibility assessments, site start up support, regulatory submission support and clinical trial auditing (GCP / GCLP and vendor audits). Through the academy training and capacity development services are also be provided