What is Research?

Interventional Vs Observational

Research studies can be both interventional and observational. Interventional studies typically compare one treatment with another, and participants receive specific interventions according to the study protocol. These interventions could be medical products, such as drugs or devices; procedures; or changes to participants' behaviour, such as diet. In an observational study, participants may still receive interventions (which can include medical products such as drugs or devices) or procedures, but this will have happened as part of their standard medical care. In observational studies, participants are not assigned to specific interventions. Research studies can take many forms, from clinical trials of drugs through to qualitative research studies. 

Below are some of the types of health research that you might commonly come across. 

Clinical trials

Clinical trials are the best way to compare different approaches to preventing and treating illness and health problems. Without trials, there is a risk that people could be given treatments which have no advantage, waste resources and could be harmful. Many treatments that are now commonly used were tested in clinical trials.

Clinical trials cover a wide range of different types of research, and can be used to find out if:

  • Treatments are safe
  • Treatments have any side effects
  • New treatments are better than available standard treatments
  • New combinations of existing medicines are more effective
  • People can be prevented from developing a particular disease, or from a disease returning

Participants are normally randomised (allocated randomly) to receive one treatment or intervention rather than another. This type of study is known as a Randomised Controlled Trial or RCT.

A new treatment can be compared to:

  • a standard approach that is already available
  • a placebo that contains no active ingredients
  • no intervention

Some studies compare multiple interventions that are already available with each other.

Clinical trials which involve administering medicinal products to participants are referred to as Clinical Trials of Investigational Medicinal Products (CTIMPs). These trials will need to meet more regulatory requirements than other kinds of clinical research studies.

All trials have guidelines about who can take part. These are called eligibility criteria. The eligibility criteria make sure that trials include the sort of people who may benefit from the treatment, and to make sure that people who take part are not put at risk.

Qualitative research

Qualitative research can take many forms, including:

  • Focus groups
  • In-depth interviews
  • Semi-structured interviews
  • Observation

Qualitative research seeks to understand other people’s perspectives and generally involves only a small group of participations. Qualitative researchers often use topic guides which outline the issues to be discussed and allow some freedom around those topics, rather than a tightly defined questionnaire. 

Qualitative research is often combined with other methods to give a wider understanding of a particular research topic.


Surveys in health research can be used to collect information on health status, quality of life and to measure the patient experience.

Surveys involve a structured questionnaire and can take a number of forms including:

  • Face to face interview surveys
  • Telephone surveys
  • Paper-based questionnaires
  • Online surveys

Researchers often use off-the-shelf questionnaires which have been validated to measure health status and quality of life. Some of these are generic, such as SF20 or the Euroquol questionnaire, and others are disease-specific. Using this type of questionnaire allows researchers to compare their findings with scores for different population groups elsewhere.

Surveys can be identifiable (but kept confidential) or they can be anonymised

Cohort Studies

A cohort study involves following a group of people over time. Study participants are not deliberately exposed to any experimental interventions.  Usually, an initial baseline assessment of participants is undertaken, and then participants are contacted again in the future for further information to be collected. At the baseline stage, participants may be divided up into groups based on their condition, their lifestyle, or their exposure to a particular environmental trigger. Follow-ups can take place after just a few years or after several decades.