CROSS-SECTIONAL VERSUS PROSPECTIVE PREDICTORS OF SCREENING MAMMOGRAPHY

Data from a population-based longitudinal study were used to compare c ross-sectional versus prospective predictors of screening mammography. Although the results of the two analyses were not dramatically differ ent, some important differences emerged. More attitudinal variables we re related to future behavior compared with past behavior. Using purel y cross-sectional data from this study to design an intervention would result in potentially important variables being deemphasized or omitt ed, which could have a significant impact on the strength of the inter vention, Our findings strongly suggest that it may be unwise to genera lize cross-sectionally obtained data to a longitudinal situation.