It is important for researchers to classify their study early on in the design process as this will often determine the ethics and regulatory approvals that are required for the study.

If you are uncertain as to how to classify your study in terms of its design (e.g. research, service evaluation, clinical audit etc.), please use the table below.

Students are encouraged to discuss this with their Supervisors as early as possible when designing their project.

RESEARCH	SERVICE EVALUATION*	CLINICAL AUDIT	SURVEILLANCE	USUAL PRACTICE (in public health)
The attempt to derive generalizable new knowledge including studies that aim to generate hypotheses as well as studies that aim to test them.	Designed and conducted solely to define or judge current care.	Designed and conducted to produce information to inform delivery of best care.	Designed to manage outbreak and help the public by identifying and understanding risks associated.	Designed to investigate outbreak or incident to help in disease control and prevention.
Quantitative research – designed to test a hypothesis. Qualitative research – identifies/explores themes following established methodology.	Designed to answer: “What standard does this service achieve?”	Designed to answer: “Does this service reach a predetermined standard?”	Designed to answer: “What is the cause of this outbreak?”	Designed to answer: “What is the cause of this outbreak?” and treat.
Addresses clearly defined questions, aims and objectives.	Measures current service without reference to a standard.	Measures against a standard.	Systematic, statistical methods to allow timely public health action.	Systematic, statistical methods may be used.
Quantitative research – may involve evaluating or comparing interventions, particularly new ones. Qualitative research – usually involves studying how interventions and relationships are experienced.	Involves an intervention in use only. The choice of treatment is that of the clinician and patient according to guidance, professional standards and/or patient preference.	Involves an intervention in use only. The choice of treatment is that of the clinician and patient according to guidance, professional standards and/or patient preference.	May involve collecting personal data and samples with the intent to manage the incident.	Any choice of treatment is based on clinical best evidence or professional consensus.
Usually involves collecting data that are additional to those for routine care but may include data collected routinely. May involve treatments, samples or investigations additional to routine care.	Usually involves analysis of existing data but may include administration of interview or questionnaire.	Usually involves analysis of existing data but may include administration of simple interview or questionnaire.	May involve analysis of existing data or administration of interview or questionnaire to those exposed.	May involve administration of interview or questionnaire to those exposed.
Quantitative research – study design may involve allocating patients to intervention groups. Qualitative research – uses a clearly defined sampling framework underpinned by conceptual or theoretical justifications.	No allocation to intervention: the health professional and patient have chosen intervention before service evaluation.	No allocation to intervention: the health professional and patient have chosen intervention before audit.	Does not involve an intervention.	May involve allocation to control group to assess risk and identify source of incident but treatment unaffected.
May involve randomisation.	No randomisation.	No randomisation.	No randomisation.	May involve randomisation but not for treatment.
Requires NHS REC review, if involving NHS patients or identifiable data, or BSREC review otherwise.	BSREC review is required.	BSREC review is required.	Does not require research ethical review.	Does not require research ethical review.

* Service development and quality improvement may fall into this category.

Further resources 

The Healthcare Quality Improvement Panel (HQIP) has also developed a useful guide which provides useful information to help differentiate between the different study types: A guide to Clinical Audit, Research and Service ReviewLink opens in a new window.

The Health Research Authority (HRA) provide an online toolLink opens in a new window that will ask a series of questions about your study, and will provide you with an answer about whether it is considered research.