Objective A potential psychological harm of screening is unexpected diagnosis—labelling. We need to know the frequency and severity of this harm to make informed decisions about screening. We asked whether current evidence allows an estimate of any psychological harm of labelling. As case studies, we used two conditions for which screening is common: prostate cancer (PCa) and abdominal aortic aneurysm (AAA).

Design Systematic review with narrative synthesis.

Data sources and eligibility criteria We searched the English language literature in PubMed, PsychINFO and Cumulative Index of Nursing and Allied Health Literature (CINAHL) for research of any design published between 1 January 2002 and 23 January 2017 that provided valid data about the psychological state of people recently diagnosed with early stage PCa or AAA. Two authors independently used explicit criteria to review and critically appraise all studies for bias, applicability and the extent to which it provided evidence about the frequency and severity of harm from labelling.

Results 35 quantitative studies (30 of PCa and 5 of AAA) met our criteria, 17 (48.6%) of which showed possible or definite psychological harm from labelling. None of these studies, however, had either appropriate measures or relevant comparisons to estimate the frequency and severity of psychological harm. Four PCa and three AAA qualitative studies all showed clear evidence of at least moderate psychological harm from labelling. Seven population-based studies found increased suicide in patients recently diagnosed with PCa.

Conclusions Although qualitative and population-based studies show that at least moderate psychological harm due to screening for PCa and AAA does occur, the current quantitative evidence is insufficient to allow a more precise estimation of frequency and severity. More sensitive measures and improved research designs are needed to fully characterise this harm. In the meantime, clinicians and recommendation panels should be aware of the occurrence of this harm.