RT Journal Article SR Electronic T1 Transition to osteoporosis for 10% of women takes 17 years for those with normal bone density, 5 years for those with moderate osteopenia: implications for the frequency of bone density testing JF Evidence Based Medicine JO Evid Based Med FD BMJ Publishing Group Ltd SP e7 OP e7 DO 10.1136/ebmed-2012-100636 VO 18 IS 1 A1 John Adam Robbins YR 2013 UL http://ebm.bmj.com/content/18/1/e7.abstract AB