Do Subjective Norms Predict the Screening of Cancer Patients’ First-Degree Relatives? A Systematic Review and Meta-Analysis

BACKGROUND: Early detection and preventive measures can reduce the risk of cancer among first degree relatives (FDRs) of cancer patients.Several studies investigated the effect of subjective norm in relation to FDRs’ tendency to conduct preventive behaviors. Therefore, the purpose of this study was to systematically evaluate the effect of subjective norms on cancer patients’ FDRs as well as their willingness for screening. METHODS: PubMed and Scopus were studied to investigate the effect of subjective norms on preventive measures such as breast cancer self-examination, colonoscopy, PSA testing, skin examination, and genetic testing. Odds Ratio (OR), correlation was and confidence intervals were extracted for meta-analysis. After reviewing the studies, only 16 studies met the criteria to be included in this systematic review. RESULTS: The meta- analysis and OR showed that Physician Recommendation (OR=6.98, 95% CI; 2.55–19.09, P<0.001), Health Care Provider (HCP) (OR=2.79, 95% CI; 1.26-6.16; P=0.011), family and friends (OR=1.82, 95% CI; 1.33–2.50, P <0.001) significantly enhanced the likelihood of referring for screening and preventive measures. CONCLUSIONS: The results of the current study indicated that subjective norms can significantly increase willingness to screening.