Table 2.1.

Types of traditional systematic reviews

Review type	Topic assessed	Elements of research question (mnemonic)
Intervention59,61	Benefits and harms of interventions used in healthcare.	Population, Intervention, Comparator, Outcome (PICO)
Diagnostic test accuracy62	How well a diagnostic test performs in diagnosing and detecting a particular disease.	Population, Index test(s), and Target condition (PIT)
Qualitative
Cochrane63	Questions are designed to improve understanding of intervention complexity, contextual variations, implementation, and stakeholder preferences and experiences.	Setting, Perspective, Intervention or Phenomenon of Interest, Comparison, Evaluation (SPICE) Sample, Phenomenon of Interest, Design, Evaluation, Research type (SPIDER) Perspective, Setting, Phenomena of interest/Problem, Environment, Comparison (optional), Time/timing, Findings (PerSPecTIF)
JBI64	Questions inform meaningfulness and appropriateness of care and the impact of illness through documentation of stakeholder experiences, preferences, and priorities.	Population, the Phenomena of Interest, and the Context (PICo)
Prognostic65	Probable course or future outcome(s) of people with a health problem.	Population, Intervention (model), Comparator, Outcomes, Timing, Setting (PICOTS)
Etiology and risk66	The relationship (association) between certain factors (e.g., genetic, environmental) and the development of a disease or condition or other health outcome.	Population or groups at risk, Exposure(s), associated Outcome(s) (disease, symptom, or health condition of interest), the context/location or the time period and the length of time when relevant (PEO)
Measurement properties 67,68	What is the most suitable instrument to measure a construct of interest in a specific study population?	Population, Instrument, Construct, Outcomes (PICO)
Prevalence and incidence69	The frequency, distribution and determinants of specific factors, health states or conditions in a defined population: eg, how common is a particular disease or condition in a specific group of individuals?	Factor, disease, symptom or health condition of interest, the epidemiological indicator used to measure its frequency (prevalence, incidence), the population or groups at risk as well as the context/location and time period where relevant (CoCoPop)