Development and preliminary validation of the cancer family impact scale for colorectal cancer.

ABSTRACT

AIM: The aim of our study was to develop a measure of how a family history of colorectal cancer (CRC) affects families from the viewpoint of unaffected family members. METHOD: Using data from 1,285 participants (637 families) in the Johns Hopkins Colon Cancer Genetic Testing study, we developed and validated The Cancer Family Impact Scale (CFIS), an instrument for use in studies investigating relationships among family factors and CRC prevention behaviors when family history is a risk factor. RESULTS: Through exploratory factor analysis (EFA) using a 50% random sample of participants, we identified 5 latent constructs among 18 items (1) NEGATIVE negative effects of cancer on the family; (2) POSITIVE positive effects of cancer on the family; (3) COMMUNICATE how families communicate about cancer; (4) FLOW how information about cancer is conveyed in families; and (5) NORM how individuals react to family norms about cancer. Confirmatory factor analysis (CFA) on the same sample showed the CFIS to have a reasonably good fit (chi(2) = 389.97, degree of freedom (df ) = 122, root mean square error of approximation = 0.06 [0.05-0.07], comparative fit index = 0.90, Tucker-Lewis index = 0.88, goodness of fit index = 0.94), and findings were cross-validated on the remaining 50% of the participants. The reliability of the scale was alpha = 0.65. CONCLUSIONS: The CFIS could be used to clarify the role that family factors play in the association between CRC family history and CRC prevention behaviors, and also aid in the development and evaluation of family-based cancer prevention interventions.