Osteoporosis knowledge: Osteoporosis Knowledge Assessment Test (Winzenberg et al. BMC Musculoskelet Disord 2003) Calcium intake: Food frequency questionnaire (Angus et al. J Am Diet Assoc 1989) Calcium and exercise self-efficacy: Osteoporosis Self-Efficacy Scale (Horan et al Res Nurs Health 1998) Physical activity: CHAMPS II (Stewart et al. J Gerontol A Biol Sci Med Sci 2001)