Table 2

PECO or PICO statement for systematic maps

ElementDescription
PopulationsAny human (epidemiological studies or human exposure studies), or animal, or ex vivo/in vitro studies using organs, tissues, cells, or cellular components, for example, cell-free receptor binding assays (experimental or toxicological studies)
Exposures or InterventionAmbient ozone exposure in epidemiological studies or ozone exposure in experimental or toxicological settings
ComparatorStudy populations or periods (person-time) exposed to a lower level of ozone (epidemiological studies) or the control groups (experimental or toxicological studies) than the more highly exposed subjects, periods (person-time) or groups
OutcomesCOPD and any health effects with high evidence levels identified in the umbrella review
  • COPD, chronic obstructive pulmonary disease; PECO, population–exposure–comparator–outcome; PICO, population–intervention–comparator–outcome.