1. Objectifs

Intentions :
«[T]he current study investigates the family cluster effect on an extended series of common behavioral and psychological outcome variables among individuals at high risk for hereditary breast and ovarian cancer undergoing BRCA1/2 genetic testing.» (p. 516)

2. Méthode

Échantillon/Matériau :
«[T]he final sample comprised 656 participants (552 women; 104 men) from 140 families» (p. 517) from the province of Quebec.

Instruments :
Questionnaire

Type de traitement des données :
Analyse statistique

3. Résumé

«In genetic studies, including those concerning psychosocial issues, the participation of family members is desired. [...] The family cluster effect is commonly assessed by the intraclass correlation coefficient (ICC), which represents the proportion of the total variance accounted for by between-cluster variation ([Merlo J, Chaix B, Yang M et al., A brief conceptual tutorial of multilevel analysis in social epidemiology: linking the statistical concept of clustering to the idea of contextual phenomenon. J Epidemiol Community Health 2005;59:443–449.). The ICC represents the degree of similarity of responses among members of an individual family. When a family cluster effect exists, the design effect (DEF) measure is required for study sample size calculation (Bland JM. Sample size in guideline trials. Fam Pract 2000;17:S17–S20).» (p. 515) «[O]ur results argue for routine evaluation and control of the family cluster effect whenever individuals from the same family are enrolled in studies on psychosocial and behavioral effects of genetic testing for cancer susceptibility and, possibly, for other conditions.» (p. 522)