Elements of External Validity of Tools for Health: An Intervention for Construction Laborers

Abstract Purpose To examine the external validity of an efficacious tailored smoking cessation and nutrition improvement telephone intervention. Design Comparison of characteristics of participants and nonparticipants (representativeness); examination of the extent of intervention implementation. Setting Cancer center collaboration with a labor union. Subjects Unionized construction laborers. Intervention Tailored feedback report, telephone counseling, and supplementary educational materials focused on smoking cessation and improved nutrition. Measures Background survey identifying socio-demographic and behavioral characteristics; process evaluation data; and final efficacy survey to determine participant satisfaction. Analysis Cross-classification and the χ2 test of homogeneity were used with categorically measured variables comparing participants and nonparticipants. We compared the means in the two groups for continuously scaled measures using the Student t-test and investigated the multivariable assoc...