False-positive findings in mammography screening induces short-term distress — breast cancer-specific concern prevails longer

Abstract

The aim of this study was to examine psychological distress in a mammography screening process as a consequence of screening after adjusting for background, personality and prescreening distress. Subjects, aged 50 years, were invitees at their first screening. There were three groups; normal findings (n=1407), false-positive findings (n=492) and referents from outside the screening programme (n=1718, age 48–49 years). Distress was measured as illness worry, anxiety, depression, cancer beliefs and early detection behaviour. Measurements were one month before screening invitation with follow-ups at 2 and 12 months postscreening. At 2 months, there was a moderate multivariate effect of group on distress; and intrusive thinking and worry about breast cancer, in particular, were most frequent amongst the false positives. Intrusive thinking still prevailed at 12 months, in addition to a higher perceived breast cancer risk and susceptibility. Distress related to screening and false-positive findings seems to be moderate, but prevailing cancer-specific concerns call for improvements in screening programmes.

Introduction

Breast cancer screening by mammography, arranged biennially in the age group of 50 years and older can reduce breast cancer mortality by 30% [1]. Many European countries have launched screening programmes for these women and the feasibility of extending screening to both younger and older age groups has also been widely discussed 2, 3. However, the psychological impact of screening, especially amongst those with false-positive screening results, has created a debate about the harm to benefit ratio of screening 4, 5, 6, 7, 8, 9, 10, and questioned the basis of launching and continuing these programmes 7, 10. Rates of abnormal mammograms in European programmes vary from 3 to 13% 11, 12, but the estimated cumulative risk of at least one false-positive mammogram in 10 screening rounds in the USA was approximately 50% [8]. Studies on the psychological impact report a short-term increase in distress, anxiety and intrusive thoughts mainly amongst those with an abnormal mammogram. Behavioural impact varies from the excess practice of breast self-examination to both increased adherence and to non-adherence of recommended screening 4, 9, 13, 14, 15, 16. However, most studies have measured only short-term psychological impact and also suffer from methodological shortcomings: for example only a few studies have had a prescreening — not to mention a pre-invitation — baseline measurement 15, 17, 18, 19. Invitation to screening and publicity campaigns inevitably make women aware of forthcoming screening and induce worry about cancer. Studies have been based on selected, often small study populations, and a variety of mostly non-standardised measures and timeframes have been used. Some prospective studies on routine screening have reported a decrease in anxiety from pre- to postscreening 15, 17. In a retrospective study [6] false-positives did not differ in anxiety or distress from population referents, but both ‘false-positives’ and ‘referents’ differed from the ‘normal finding’ group in being more distressed. These differences were interpreted more as relief in the ‘normal finding’ group than as raised anxiety and distress in the ‘false-positive’ group.

The aim of the present study was to evaluate the psychological distress induced by a mammography screening process and by the type of finding amongst women invited to their first screening round. In addition to having both short- and long-term measurements, we have taken into account background factors, personality factors and prescreening levels of distress, and we present the results using standardised indices of effect size.