CLINICAL GUIDELINETreatment of Low Bone Density or Osteoporosis to Prevent Fracturesin Men and Women: A Clinical Practice Guideline Update from theAmerican College of PhysiciansAmir Qaseem, MD, PhD, MHA; MaryAnn Forciea, MD; Robert M. McLean, MD; and Thomas D. Denberg, MD, PhD; for the Clinical Guidelines Committee of the American College of Physicians*Description: This guideline updates the 2008 American Col- lege of Physicians (ACP) recommendations on treatment of low bone density and osteoporosis to prevent fractures in men and women. This guideline is endorsed by the American Academy of Family Physicians.Methods: The ACP Clinical Guidelines Committee based these recommendations on a systematic review of randomized con- trolled trials; systematic reviews; large observational studies (for adverse events); and case reports (for rare events) that were pub- lished between 2 January 2005 and 3 June 2011. The review was updated to July 2016 by using a machine-learning method, and a limited update to October 2016 was done. Clinical outcomes evaluated were fractures and adverse events. This guideline fo- cuses on the comparative benefits and risks of short- and long- term pharmacologic treatments for low bone density, including pharmaceutical prescriptions, calcium, vitamin D, and estrogen. Evidence was graded according to the GRADE (Grading of Recommendations Assessment, Development and Evaluation) system.Target Audience and Patient Population: The target audi- ence for this guideline includes all clinicians. The target patient population includes men and women with low bone density and osteoporosis.Recommendations: Recommendation 1: ACP recommends that clinicians offer pharmacologic treatment with alendronate, risedronate, zoledronic acid, or denosumab to reduce the risk for hip and vertebral fractures in women who have known osteopo- rosis. (Grade: strong recommendation; high-quality evidence)Recommendation 2: ACP recommends that clinicians treat os- teoporotic women with pharmacologic therapy for 5 years. (Grade: weak recommendation; low-quality evidence)Recommendation 3: ACP recommends that clinicians offer pharmacologic treatment with bisphosphonates to reduce the risk for vertebral fracture in men who have clinically recog- nized osteoporosis. (Grade: weak recommendation; low-quality evidence)Recommendation 4: ACP recommends against bone density monitoring during the 5-year pharmacologic treatment period for osteoporosis in women. (Grade: weak recommendation; low- quality evidence)Recommendation 5: ACP recommends against using meno- pausal estrogen therapy or menopausal estrogen plus progesto- gen therapy or raloxifene for the treatment of osteoporosis in women. (Grade: strong recommendation; moderate-quality evidence)Recommendation 6: ACP recommends that clinicians should make the decision whether to treat osteopenic women 65 years of age or older who are at a high risk for...