Consistency and sources of divergence in recommendations on screening with questionnaires for presently experienced health problems or symptoms: a comparison of recommendations from the Canadian Task Force on Preventive Health Care, UK National Screening Committee, and US Preventive Services Task Force

Background Recently, health screening recommendations have gone beyond screening for early-stage, asymptomatic disease to include “screening” for presently experienced health problems and symptoms using self-report questionnaires. We examined recommendations from three major national guideline organizations to determine the consistency of recommendations, identify sources of divergent recommendations, and determine if guideline organizations have identified any direct randomized controlled trial (RCT) evidence for the effectiveness of questionnaire-based screening.