[Evidence and practice: How do primary care physicians evaluate screening interventions? A questionnaire study]

Abstract

Background: Patients receiving a screening intervention have to be informed about risks and benefits. On the part of the physician, it requires the understanding of statistical evidence and statistical literacy.

Objectives: Do general practitioners (GPs) make different recommendations on screening interventions if they only rely on statistics compared to their decisions in everyday practice? Are the decisions relying on statistics and the decisions made in everyday practice consistent with official recommendations? Does the way of presenting the numbers (table versus pictogram) affect the decision?

Methods: Online survey among German GPs. The GPs were asked to make recommendations for three different screening scenarios which were based on statistical evidence of existing screening interventions. To avoid bias, statistics were not presented in relation to the actual diseases. The numbers were presented in either a table or a pictogram. Afterwards, the GPs were asked for their recommendations on the same screening interventions in everyday practice.

Results: Forty-three GPs were surveyed. Compared to everyday medical practice, participants were less likely to recommend a screening intervention when being confronted with the underlying statistical evidence (F (1, 3)=104.83, p=.002, η_partial²=.97). Most of the decisions in everyday practice were consistent with official recommendations, while their decisions relying on statistics were more likely to deviate from them (everyday practice, M=1.79, SD=0.77; scenario, M=1.44, SD=0.80; t (42)=-2.29, p=.03). The way the numbers were presented did not affect the decision (t (127)=-1.83, p=.07).

Conclusions: In everyday practice, GPs' screening recommendations do not seem to be based on statistical evidence. Presumably they would be more reluctant to recommend screening interventions if they knew the statistical evidence.

Keywords: Empfehlung; Entscheidungsfindung; Evidenzbasierte Medizin; Früherkennung; Hausärzte; cancer screening; decision making; evidence-based medicine; general practitioners; recommendation.