Testing whether barriers to a hypothetical screening test affect unrelated perceived benefits and vice versa: A randomised, experimental study

Alex Ghanouni,Ella Nuttall,Jane Wardle,Christian Von Wagner

doi:10.1016/j.pec.2016.09.007

Abstract

ObjectiveDetermine whether (fictitious) health screening test benefits affect perceptions of (unrelated) barriers, and barriers affect perceptions of benefits. MethodsUK adults were recruited via an online survey panel and randomised to receive a vignette describing a hypothetical screening test with either high or low benefits (higher vs. lower mortality reduction) and high or low barriers (severe vs. mild side-effects; a 2×2 factorial design). ANOVAs compared mean perceived benefits and barriers scores. Screening ‘intentions’ were compared using Pearson’s χ2 test. ResultsBenefits were rated less favourably when barriers were high (mean: 27.4, standard deviation: 5.3) than when they were low (M: 28.5, SD: 4.8; p=0.010, partial η2=0.031). Barriers were rated more negatively when benefits were low (M: 17.1, SD: 7.6) than when they were high (M: 15.7, SD: 7.3; p=0.023, partial η2=0.024). Most intended to have the test in all conditions (73–81%); except for the low benefit-high barrier condition (37%; p<0.0005; N=218). ConclusionsPerceptions of test attributes may be influenced by unrelated characteristics. Practice implicationsReducing screening test barriers alone may have suboptimal effects on perceptions of barriers if benefits remain low; increasing screening benefits may not improve perceptions of benefits if barriers remain high.

Highlights

Screening is an important public health strategy for reducing cancer mortality and incidence
Most intended to have the test in all conditions (73–81%); except for the low benefithigh barrier condition (37%; p < 0.0005; N = 218)
This test can include an intravenous dye that carries a small risk of an adverse reaction, consisting of nausea and vomiting [13], the severity of which was manipulated as a screening test barrier (“severe nausea and regular vomiting for 3 days”; “mild nausea and occasional vomiting for 5 minutes”)

Summary

Introduction

Screening is an important public health strategy for reducing cancer mortality and incidence. Much informative research has been carried out on how invitees perceive benefits and barriers of screening in order to address the policy goal of improving uptake (and satisfaction with screening services in general). Studies in this area have often been guided by psychological theories which assume implicitly that perceptions of barriers and benefits are independent. The Health Belief Model [1] includes benefits and barriers as discrete ‘constructs’ that are often analysed separately Similar conceptual and analytical approaches are apparent in less theoretically-oriented research (e.g. where perceived barriers are examined without assessment of perceived benefts [4])

Methods

Results

Conclusion