Low-dose oral contraceptives and bone mineral density: An evidence-based analysis

WE reviewed studies of the association of oral contraceptive (OC) use and b one mineral density (BMD). We limited the review to studies of women using low-dose oral contraceptives and that measured BMD by bone densitometry. A total of 13 studies met the inclusion criteria. Nine of these showed a posi tive effect of oc use on BMD, and four did not show an association. However , none of the studies showed a decrease in BMD with OC use. We classified t he level of evidence from each study according to the guidelines of the US Preventive Services Task Force. The level of evidence supporting a positive association between OC use and increased BMD is 11-1. There is fair eviden ce (Category B) to support the position that OC use has a favorable effect on BMD. We mane suggestions for a study design that could yield Level I evi dence. (C) 2000 Elsevier Science Inc. All rights reserved.