quantitative ultrasound and bone mineral density are equally strongly associated with risk factors for osteoporosis because resources do not allow all women to be screened for osteoporosis clinical risk factors are often used to identify those individuals at increased risk of fracture who are then assessed by bone densitometry the aim of this study was to compare calcaneal quantitative ultrasound qus and axial bone mineral density bmd t and z scores in a large group of women some with no clinical risk factors and others with one or more risk factors for osteoporosis the study population consisted of 1115 pre and postmenopausal women a subgroup of 530 women was used to construct reference data for calculating t and z scores a total of 786 women was found to have one or more of the following risk factors i atraumatic fracture since the age of 25 years ii report of xray osteopenia iii predisposing medical condition or use of therapy known to affect bone metabolism iv premature menopause before the age of 45 years or a history of amenorrhea of longer than 6 months duration v family history of osteoporosis vi body mass index bmi 20 kgm2 and vii current smoking habit calcaneal broadband ultrasound attenuation bua and speed of sound sos measurements were performed on a hologic sahara and a dtuone and bmd was measured at the spine and hip using dualenergy xray absorptiometry dxa the z score decrements associated with the seven risk factors calculated using multivariate regression analysis were similar for qus and bmd measurements z score decrements mean of bmd and qus measurements combined associated with a history of atraumatic fracture 067 xray osteopenia 036 a family history of osteoporosis 023 and a low bmi 053 were all statistically significant compared with women with no risk factors z score decrements associated with a medical condition or use of therapy known to affect bone metabolism a premature menopause or prolonged amenorrhea or those who were current smokers were not significantly different from zero as the number of risk factors present in each individual increased the mean z score decrements became more negative increasing from 028 for women with one risk factor to 119 for those with four or more risk factors qus and bmd measurements yielded similar mean z scores for women with one two three or more than four risk factors using the world health organization who criteria to diagnose osteoporosis for bmd measurements and revised diagnostic criteria for qus approximately onethird of postmenopausal women aged 50 years with clinical risk factors were classified as osteoporotic compared with only 12 of women without clinical risk factors over twothirds of postmenopausal women with risk factors were classified as osteopenic or osteoporotic and approximately 28 were classified as normal the proportion of women classified into each diagnostic category was similar for bmd and qus in conclusion clinical risk factors for osteoporosis affected calcaneal bua and sos z score measurements to the same extent as axial bmd z score measurements