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. 2020 Jul 13;2020(56):97–113. doi: 10.1093/jncimonographs/lgaa009

Table A1.

PECO statementa

PECO element1 Evidence stream Articles or features included Articles or features excluded
Population Human

  • Any population

  • All life stages

  • Study designs
    • Cohort
    • Case-cohort
    • Case-control
    • Nested case-control

  • Residential radon exposed, uranium miners and millers, Mayak workers, radiation therapy patients

  • RCT, controlled exposure, case series, cross-sectional, ecologic, mechanistic studies
Exposure Human
  • Ionizing radiation exposure
    • Gamma
    • X-ray
    • Low-LET

  • Quantitative in units of equivalent or effective dose (eg, mSv, Sv) or absorbed dose (eg, mGy, Gy)

  • Primary route of exposure by inhalation, oral, or dermal type (eg, intraperitoneal, injection)

  • Semiquantitative or qualitative estimates of exposure
Comparator Human

  • A comparison population [not exposed, exposed to lower levels, exposed below detection]

  • Effect measurements reported as RR, ERR, excess absolute risk, or attributable risk

  • No comparison group
Outcome Human

  • Endpoints: Cancers (death or incidence)

  • Cancer endpoints not described
General considerations

  • Reports primary source

  • Full text available

  • Limit 2006 to current

  • Reports a secondary source (eg, review articles)

  • Editorials

  • Proceedings

  • Correspondence
a

ERR = excess relative risk; LET = linear energy transfer; PECO = Population, Exposure, Comparator, and Outcome; RCT = randomized control trial; RR = relative risk.