A research question can stem from noticing a phenomena during your clinical practice, exploring emerging topics in your area of expertise more deeply, identifying standards of practice which have not been recently reviewed, or really anything that piques your interest. Attempt to ask open ended questions to identify gaps or unresolved disagreements in your field. Consulting with colleagues and experts in your field is another valuable way to explore potential research topics.
Once you've identified an area you'd like to study, attempt to formulate a scientific/research hypothesis.
At this stage, you'll want to identify your research hypothesis (remember, this is not a statistical hypothesis). A research hypothesis is a testable idea that your research question seeks to answer. For example, your research question may be "How does Drug A affect people with Condition 1 versus Condition 2?" and your hypothesis may be "People with Condition 1 respond better to treatment with Drug A than people with Condition 2."
Systematic reviews require a specific, answerable clinical question. Typically these are framed using PICO - Patient/Problem/Population; Intervention; Complication/Counter-intervention; Outcome. Sometimes you can include Methodology, Time Factors, or Type of study.
Breaking your question into domains, or "chunking" your question, gives you the added benefit of allowing you to start building search strategies for literature databases. Use these chunks to identify keyword synonyms and find controlled vocabulary, as well as to identify concepts to eliminate (e.g. if you're interested in a surgical intervention, you will know to avoid searching for pharmaceutical interventions on the topic). An example of using PICO could be:
P: People with Condition 1
I: Drug A
C: People with Condition 2
O: Decreased symptoms
Other Frameworks
Evidence Synthesis projects (projects on topics outside of health sciences) may use other frameworks that are not focused on clinical topics. Some examples of these are SPICE (Setting; Perspective; Intervention/Exposure; Comparison; Evaluation) or SPIDER (Sample; Phenomenon; Design; Evaluation; Study Type).