Screening Frameworks

Organising a Screening Service (e.g Breast cancer)

  • Identifying women to be screened
  • Invitations
  • Non- invited - fail safe mechanism so positive results leads to action
  • Basic screening - taking mammograms, reading, notifying
  • Localised screening units
  • Assessment and biopsy
  • Screening records systems
  • Identification, invitation, recall
  • Attendance, test/recall
  • Monitoring process/ effectiveness
  • Quality of mammography between and within centres
  • Radiation protection/ monitoring

Criteria for appraising screening

Use mnemonic: 'PRAT WILSON'

P - Protocols
R - Resources for screening and treatment
A - Activity continuous
T - treatable condition
W - Worthwhile - evidence of effectiveness
I - Importance - incidence / death rate
L - Latent phase - early detectable phase
S - Suitable and acceptable test
O - Outcome improved by early detection - benefits >harm
N - National History known

Then add: 1990's criteria for appraising screening to PRAT WILSON.

  1. Is there evidence from RCT that proposed screening reduces death rate

  2. If yes - what is NNT

  3. If yes - how many people adversely affected by screening: / 1000 screened or / life saved.

  4. If yes - how broad are Confidence intervals

  5. If yes - what are financial cost of screening program.