Comparing two theories of health behavior: a prospective study of noncompletion of treatment following cervical cancer screening.

Some women receiving abnormal cervical screening tests do not complete recommended treatment. A prospective study (N = 660) investigated the value of conceptualizing attendance at colposcopy for treatment as either (a) an active problem-solving response to a health threat, motivated by attitudes toward an abnormal result, as implied by self-regulation theory (H. Leventhal, D. Meyer, & D. Nerenz, 1980); or (b) as a behavior motivated by attitudes toward clinic attendance, as implied by the theory of planned behavior (TPB; I. Ajzen, 1985). Responses to questionnaires containing variables specified by these models were used to predict women's subsequent attendance or nonattendance for treatment over the following 15 months. Although the TPB offered superior prediction of intentions and completion of treatment, discriminant function analyses showed that consideration of both models was important in distinguishing between those who attended all their appointments as scheduled, attended after being prompted, or ceased attending. Implications for measurement and theory in health protection are discussed.