The review protocol should provide an explicit and clear statement of the review questions addressed in the review. The review questions should specify the focus of the review (effectiveness), the types of participants, types of interventions and comparators, and the types of outcomes considered. Usually, reviewers use the PICO mnemonic (population, intervention, comparator and outcome) to construct a clear and meaningful review objective/question regarding the quantitative evidence on effectiveness of interventions.
Examples of review questions: ‘In community dwelling patients with stable, moderate-to-severe chronic obstructive pulmonary disease’:
- What is the effect of inspiratory muscle training versus no specific training on dyspnea and functional ability?
- What is the effect of inspiratory muscle training versus no specific training on inspiratory muscle strength and endurance?
- What is the effect of inspiratory muscle training on hypoxemia and discomfort?
There should be consistency between the review title and the review questions in terms of the focus of the review. Review authors are encouraged to read the article by Stern et al (2014) regarding the review questions and the inclusion criteria.