Cluster-randomised non-inferiority trial comparing DVD-assisted and traditional genetic counselling in systematic population testing for BRCA1/2 mutations
Manchanda R., Burnell M., Loggenberg K., Desai R., Wardle J., Sanderson SC., Gessler S., Side L., Balogun N., Kumar A., Dorkins H., Wallis Y., Chapman C., Tomlinson I., Taylor R., Jacobs C., Legood R., Raikou M., McGuire A., Beller U., Menon U., Jacobs I.
Background Newer approaches to genetic counselling are required for population-based testing. We compare traditional face-to-face genetic counselling with a DVD-assisted approach for population-based BRCA1/2 testing. Methods A cluster-randomised non-inferiority trial in the London Ashkenazi Jewish population. Inclusion criteria Ashkenazi Jewish men/women >18 years; exclusion criteria: (a) known BRCA1/2 mutation, (b) previous BRCA1/2 testing and (c) firstdegree relative of BRCA1/2 carrier. Ashkenazi Jewish men/women underwent pre-test genetic counselling prior to BRCA1/2 testing in the Genetic Cancer Prediction through Population Screening trial (ISRCTN73338115). Genetic counselling clinics (clusters) were randomised to traditional counselling (TC) and DVD-based counselling (DVD-C) approaches. DVD-C involved a DVD presentation followed by shorter face-toface genetic counselling. Outcome measures included genetic testing uptake, cancer risk perception, increase in knowledge, counselling time and satisfaction (Genetic Counselling Satisfaction Scale). Random-effects models adjusted for covariates compared outcomes between TC and DVD-C groups. One-sided 97.5% CI was used to determine non-inferiority. Secondary outcomes: relevance, satisfaction, adequacy, emotional impact and improved understanding with the DVD; costminimisation analysis for TC and DVD-C approaches. Results 936 individuals (clusters=256, mean-size=3.6) were randomised to TC (n=527, clusters=134) and DVD-C (n=409, clusters=122) approaches. Groups were similar at baseline, mean age=53.9 (SD=15) years, women=66.8%, men=33.2%. DVD-C was non-inferior to TC for increase in knowledge (d=-0.07; lower 97.5% CI=-0.41), counselling satisfaction (d=-0.38, 97.5% CI=1.2) and risk perception (d=0.08; upper 97.5% CI=3.1). Group differences and CIs did not cross non-inferiority margins. DVD-C was equivalent to TC for uptake of genetic testing (d=-3%; lower/upper 97.5% CI -7.9%/1.7%) and superior for counselling time (20.4 (CI 18.7 to 22.2) min reduction (p<0.005)). 98% people found the DVD length and information satisfactory. 85-89% felt it improved their understanding of risks/benefits/implications/purpose of genetic testing. 95% would recommend it to others. The cost of genetic counselling for DVD-C=£7787 and TC=£17 307. DVD-C resulted in cost savings=£9520 (£14/volunteer). Conclusions DVD-C is an effective, acceptable, noninferior, time-saving and cost-efficient alternative to TC. Trial registration number ISRCTN 73338115.