When developing your research question, it's useful to consider the type of question you are asking. This will focus your question and can help determine what framework to use (e.g. PICO) and what study designs will best answer your question. We’ve provided a brief description of some common question types below.


Therapy (Intervention / Treatment)

These questions aim to evaluate the effectiveness of different interventions (treatments, drugs, therapy, educational changes, social changes, etc) in improving some outcome(s).

Example: In patients with osteoarthritis of the knee, is hydrotherapy more effective than traditional physiotherapy in relieving pain?



These questions aim to evaluate the effectiveness of an intervention or exposure in preventing morbidity and mortality.

Example: For obese children, does the use of community recreational activities reduce the risk of diabetes, compared with educational programmes?


Etiology (Harm / Causation)

These questions aim to evaluate the harmful effect of an intervention or exposure.

Example: Do adults who binge drink compared with those who do not binge drink have higher mortality rates?



These questions aim to compare the accuracy and safety of diagnostic tests against the standard method.

Example: For deep vein thrombosis is D-dimer testing or ultrasound more accurate for diagnosis?


Prognosis (Forecast)

These questions aim to explore the likelihood of specific outcomes for patients with particular disorders.

Example: In healthy older women that suffer hip fractures within the year after injury, what is the relative risk of death?


Qualitative (Meaning)

These questions aim to synthesise qualitative evidence to address questions on aspects of interventions other than effectiveness.

Example: What are women's experiences of menopause?