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. Methods: We reviewed recommendation statements listed by the Canadian Task Force on Preventive Health Care (CTFPHC), the United Kingdom National Screening Committee (UKNSC), and the United States Preventive Services Task Force (USPSTF) as of 5 September 2016. Eligible recommendations focused on using self-report questionnaires to identify patients with presently experienced health problems or symptoms. Within each recommendation and accompanying evidence review we identified screening RCTs. Results: We identified 22 separate recommendations on questionnaire-based screening, including three CTFPHC recommendations against screening, eight UKNSC recommendations against screening, four USPSTF recommendations in favor of screening (alcohol misuse, adolescent depression, adult depression, intimate partner violence), and seven USPSTF recommendations that did not recommend for or against screening. In the four cases where the USPSTF recommended screening, either the CTFPHC, the UKNSC, or both recommended against. When recommendations diverged, the USPSTF expressed confidence in benefits based on indirect evidence, evaluated potential harms as minimal, and did not consider cost or resource use. CTFPHC and UKNSC recommendations against screening, on the other hand, focused on the lack of direct evidence of benefit and raised concerns about harms to patients and resource use. Of six RCTs that directly evaluated screening interventions, five did not report any statistically significant primary or secondary health outcomes in favor of screening, and one trial reported equivocal results. Conclusions: Only the USPSTF has made any recommendations for screening with questionnaires for presently experienced problems or symptoms. The CTFPHC and UKNSC recommended against screening in all of their recommendations. Differences in recommendations appear to reflect differences in willingness to assume benefit from indirect evidence and different approaches to assessing possible harms and resource consumption. There were no examples in any recommendations of RCTs with direct evidence of improved health outcomes.