Clinical research is about people – patients, former patients, and people who are well. The goal is to find out what causes human disease, and how it can be prevented and treated. Each clinical research study is designed to answer a specific question, for example about the causes, origins, diagnosis, prevention, outcomes or treatments for a particular disease. Clinical trials are one important kind of clinical research, but there are others.

Categories of clinical research

Clinical research involves at least one of the following:

  • Human participation: studies that require face-to-face contact with patients and/or healthy human participants, for example clinical trials.  
  • Records based studies: studies that require access to personal data on health or lifestyle without involving face-to-face contact with any people, examples include information obtained about individuals by telephone, questionnaires, surveys or data retrieval.  
  • Clinical samples: studies that involve laboratory studies on human material, examples include examinations of blood, biopsy material or post-mortem tissue.  
  • Technology development for clinical use: development or adaptation of technologies for diagnosis or therapy, for example photodynamic therapy.

Why should we do clinical research?

Clinical research is important because it is the best way to improve the treatment and care of people who are sick. Clinical research gives us essential information about the effects of different treatments – information that doctors and patients cannot find in any other way. Clinical trials are how we discover if new treatments are more effective or have fewer side effects, and how to weigh up the possible benefits and harms of a new treatment.

What are the common types of research questions answered by clinical research?

  • How can we identify which polyps in the bowel are nasty and which are harmless? With this knowledge we may be able to avoid many people developing bowel cancer and having to undergo extensive and expensive treatment.  
  • Can we help people with advanced cancer who feel sad, anxious, tired or weak but aren’t clinically depressed by giving them an antidepressant? The researchers running the ZEST trial wondered if an antidepressant might help these people to feel better, and to cope better with their illness and treatment.  
  • Can magnetic resonance techniques be used to find thyroid cancer? If magnetic resonance spectroscopy is successfully developed for the fast and accurate assessment of thyroid nodules, patients with benign thyroid disease won’t have to undergo surgery to exclude cancer.  
  • When is it best to start hormone therapy for men with relapsed or advanced prostate cancer? Starting hormone therapy earlier may be more effective than staring it later, but it also means having side effects for longer. This research will determine the effects of starting earlier or later on length and quality of life.    
  • Can motion compensation in Positron Emission Tomography (PET) imaging improve lung cancer diagnosis and treatment? When PET is used for chest examinations, the motion caused from breathing can blur and distort the images. A new technique that compensates for respiratory motion might detect chest lesions more accurately. Consequently patients could avoid the trauma and expense of surgery.


Clinical research takes lots of effort, time and money. Clinical trials are expensive and usually funded by research grants from organisations like The Cancer Council and the National Health and Medical Research Council, or by companies that produce the treatments being tested, like pharmaceutical companies and device manufacturers.

Taking part in clinical research should not cost the research participant any more money than not taking part. Some of the tests and treatments involved in clinical trials are part of standard care. The researchers should cover the cost of any extra tests or treatments that are not part of standard care.
Participation in clinical research generally means extra work for doctors, nurses and other research staff. In many cases, the research group or company responsible for the research provides funds to help pay for some or all of these extra costs.

What research methods are used in clinical research?

Clinical research can be done prospectively (going forward in time) by observing people and seeing what happens to them in the future, or retrospectively (looking back in time) by reviewing medical or administrative records to discover what has already happened. Prospective studies are more reliable because they are less prone to bias and loss of data than retrospective studies. However, retrospective studies are easier, quicker, and more feasible, especially for rare diseases that require long follow-up.

Successful clinical studies acknowledge the complexity of conducting scientific research with human subjects, and require both good experimental design and respect for the rights of study participants. The outcomes of treatments in individual people are often highly variable, so reliable designs that give unbiased results are critical. All clinical research requires approval from the local Human Research Ethics Committee before it can go ahead. Every prospective clinical study should contain a participant information sheet that explains the possible risks and benefits for participants in clear, non-technical terms.

Who conducts clinical research?

Clinical research is done by a vast range of organisations including cooperative trials groups, research institutes, universities, hospitals, and pharmaceutical companies. Clinical studies often involve a wide array of individuals, from a variety of medical, nursing, scientific, and other backgrounds.
Reproduced with the kind permission of Cancer Council New South Wales.