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