Objective: Our aim was to investigate the reliability of the information on family history of cancer in first-degree relatives in a hospital-based case-control study.
Study design and setting: We re-interviewed at home 294 controls of an Italian hospital-based case-control study on digestive tract neoplasms using the same questionnaire and compared the responses reported by these patients in the two settings.
Results: A satisfactory agreement between the two interviews was reported for family history of any cancer (kappa=0.7) and of cancers of the digestive tract (kappa=0.8). The agreement was apparently higher for esophageal and stomach cancers (kappa>0.8) than for intestinal cancers (kappa=0.6) and lower for lung cancer (kappa=0.5). We found a systematic tendency to report a history of cancer more frequently in the hospital setting than in the home setting.
Conclusion: The present study showed a good reliability of data on family history of all cancers, including cancers of the digestive tract, provided by hospital controls through a structured interview-administered questionnaire. It suggests, moreover, that controls in the hospital setting tend to recall more often, and presumably more completely, a family history of cancer.