Understanding why negative genetic test results sometimes fail to reassure.

A proportion of those receiving negative results following predictive genetic testing desire future bowel screening. This is despite a negative result meaning a general population risk of 1:7500 and despite bowel screening being experienced as aversive and clinically unnecessary. This study aimed to investigate perceptions of risk, illness, and tests amongst those receiving negative results following predictive genetic testing. Interviews with nine people receiving negative genetic test results for familial adenomatous polyposis (FAP) were analyzed using the qualitative method, interpretative phenomenological analysis (IPA). Those not reassured by negative genetic test results perceived a continuing risk to themselves and to their children. Two sets of perceptions emerged that might explain this: (1). perceptions of the genetic basis of the condition (FAP). Although the condition was perceived to be genetic, genetic status was seen as transient, so a result today could not predict the future. The condition was also seen as caused by factors other than genes, so information about only one risk factor could not be reassuring. (2). Perceptions of the genetic test. There was a lack of conviction in the ability of the genetic test, based on a blood sample, to predict a disease located in the bowel. These results suggest that some individuals receiving negative test results are not reassured because of their representations of the cause of their condition and the nature of the tests they undergo. It may be that eliciting and, when appropriate, changing people's representations prior to testing may enable those receiving negative results to be more reassured about their residual risk. Copyright 2003 Wiley-Liss, Inc.