***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: The National Institutes of Health 's consensus conference ( 1 ) defined osteoporosis as a skeletal disorder characterized by compromised bone strength predisposing to an increased risk for fracture . Bone strength reflects the integration of two main features : bone density and bone quality .Bone quality refers to architecture , turnover , damage accumulation ( e.g. , microfractures ) , and mineralization . Although osteoporosis can affect any bone , the hip , spine , and wrist are most likely to be affected . Osteoporosis affects an estimated 44 million Americans or 55 % of people 50 years of age or older . Another 34 million Americans are estimated to have low bone mass , meaning that they are at an increased risk for osteoporosis . Osteoporosis can be diagnosed by the occurrence of fragility fracture . In patients without fragility fracture , osteoporosis is often diagnosed by low bone density .  Dual x-ray absorptiometry ( DXA ) is the current gold st and ard test for diagnosing osteoporosis in people without an osteoporotic fracture .  Dual x-ray absorptiometry results are scored as st and ard deviations ( SDs ) from a young healthy norm ( usually female ) and reported as T-scores . For example , a T-score of 2 indicates a bone mineral density that is 2 SDs below the comparative norm . The international reference st and ard for the description of osteoporosis in postmenopausal women and in men age 50 years or older is a femoral neck bone mineral density of 2.5 SD or more below the young female adult mean ( 2 ) . Low bone density , as measured by DXA , is an imperfect predictor of fracture risk , identifying fewer than half the people who go on to have an osteoporotic fracture . Screening guidelines for women are well established ( 3 ) , and the American College of Physicians ( ACP ) recently published guidelines on screening for men ( 4 ) . This guideline presents the available evidence on various pharmacologic treatments to prevent fractures in men and women with low bone density or osteoporosis . Medications used to treat osteoporosis may affect different parts of the skeletal system differently , and efficacy for vertebral fractures does not necessarily imply efficacy for nonvertebral fractures . The target audience for this guideline is all clinicians and the target patient population is all adult men and women with low bone density or osteoporosis . These recommendations are based on the systematic evidence review by MacLean and colleagues ( 5 ) and the Agency for Healthcare Research and Quality sponsored Southern California Evidence -Based Practice Center evidence report ( 6 ) . The drugs currently approved for prevention of osteoporosis include alendronate , ib and ronate , risedronate , zoledronic acid , estrogen , and raloxifene . The drugs currently approved for treatment of osteoporosis include alendronate , ib and ronate , risedronate , calcitonin , teriparatide , zoledronic acid ( in postmenopausal women ) , and raloxifene . Testosterone , pamidronate , and etidronate are not approved by the U.S. Food and Drug Administration for the treatment or prevention of osteoporosis . Methods The literature search done by MacLean and colleagues for the systematic review ( 5 ) included studies from MEDLINE ( 1966 to December 2006 ) , the ACP Journal Club data base , the Cochrane Central Register of Controlled Trials ( no date limits ) , the Cochrane Data base of Systematic Review s ( no date limits ) , Web sites of the United Kingdom National Institute of Health and Clinical Excellence ( no date limits ) , and the United Kingdom Health Technology Assessment Program ( January 1998 to December 2006 ) . The review ers limited their search to English- language publications and human studies . They derived evidence for comparative benefits of various treatments exclusively from r and omized , controlled trials , whereas they included evidence from other types of studies for short- and long-term harms . Two physicians independently abstract ed data about study population s , interventions , follow-up , and outcome ascertainment by using a structured form . For each group within a r and omized trial , a statistician extracted the sample size and number of persons reporting fractures . Two review ers , under the supervision of the statistician , independently abstract ed information about adverse events . The statistician or the principal investigator resolved disagreements . This guideline is based on an evaluation of 76 r and omized , controlled trials , 4 of which were identified in the up date d search , and 24 meta-analyses that were included in the efficacy analyses . The analyses of adverse events included 491 articles , representing 417 r and omized trials , 25 other controlled clinical trials , 11 open-label trials , 31 large observational studies , and 9 case reports of osteonecrosis among bisphosphonate users . MacLean and colleagues ' background article ( 5 ) includes details about the methods used for the systematic evidence review . The ACP rates the evidence and recommendations by using the Grading of Recommendations , Assessment , Development , and Evaluation ( GRADE ) system with minor modifications ( Table 1 ) . In addition , the evidence review ers used predefined criteria to assess the quality of systematic review s and r and omized trials , based on internal and external validity assessment s detailed in the Quality of Reporting of Meta-Analyses ( QUOROM ) statement ( 7 ) . Table 1 . The American College of Physicians ' Guideline Grading System The objective of this guideline is to synthesize the evidence for the following questions : What are the comparative benefits in fracture reduction among and also within the following treatments for low bone density :  bisphosphonates , specifically alendronate , risedronate , etidronate , ib and ronate , pamidronate , and zoledronic acid ; calcitonin ; estrogen for women ; teriparatide ; selective estrogen receptor modulators ( SERMs ) , specifically raloxifene and tamoxifen ; testosterone for men ; vitamins and minerals , specifically vitamin D and calcium ; and the combination of calcium plus vitamin D ? How does fracture reduction result ing from treatments vary among individuals with different risks for fracture as determined by bone mineral density ( borderline , low , or severe ) , previous fractures ( prevention vs. treatment ) , age , sex , glucocorticoid use , and other factors ( such as community-dwelling vs. institutionalized or vitamin Ddeficient vs. not ) ? What are the short- and long-term harms ( adverse effects ) of these therapies , and do these vary by specific sub population s ? Comparative Benefits of Drugs versus Placebo in Fracture Reduction Evidence from 24 meta-analyses ( 830 ) and 35 additional r and omized trials published after the meta-analyses ( 3165 ) described the effect of 9 of the 14 agents ( alendronate , etidronate , risedronate , calcitonin , estrogen , teriparatide , raloxifene , calcium , and vitamin D ) on fracture incidence . For 4 agents ( ib and ronate , pamidronate , zoledronic acid , and tamoxifen ) , the review ers found no meta-analyses and instead gathered the evidence from 14 r and omized trials ( 6679 ) . No studies were found that reported fracture rates for testosterone . Three r and omized trials ( 35 , 80 , 81 ) and 1 meta- analysis ( 82 ) evaluated the combination of calcium plus vitamin D  on fractures .  Bisphosphonates Good- quality evidence showed that alendronate , etidronate , ib and ronate , and risedronate prevent vertebral fractures . In addition , evidence from good- quality studies demonstrated that both alendronate and risedronate prevent nonvertebral and hip fractures . Two large r and omized trials showed that zoledronic acid prevents vertebral and nonvertebral fractures in high-risk population s and reduces the risk for hip fracture ( 67 , 74 ) . Ib and ronate has not been shown to reduce nonvertebral fractures ( 68 ) . Of the 6 fairly small trials that looked at vertebral fractures , 1 demonstrated a statistically significant reduction in fractures with pamidronate relative to placebo ( 0.14 [ 95 % CI , 0.03 to 0.72 ] ) ( 73 ) . However , after these data were pooled , the pooled risk estimate for fractures for pamidronate relative to placebo was not significant ( 0.52 [ CI , 0.21 to 1.24 ] ) ( 6 ) . Calcitonin Fair- quality evidence shows that calcitonin reduces vertebral fractures ( 83 , 84 ) . Good- quality evidence indicates that calcitonin does not reduce nonvertebral fractures ( 13 , 16 ) . Estrogen Good- quality evidence shows that estrogen reduces the incidence of vertebral ( 29 , 85 ) , nonvertebral ( 86 ) , and hip fractures ( 85 ) . Teriparatide Good- quality evidence shows that teriparatide prevents vertebral fractures . The evidence related to teriparatide preventing nonvertebral fractures is mixed ; 1 large r and omized trial showed a reduction in nonvertebral fractures ( 34 ) but 2 small trials did not ( 87 , 88 ) . SERMs Good- quality evidence shows that raloxifene prevents vertebral fractures , but that tamoxifen has no effect on vertebral fractures ( 8991 ) . In addition , both raloxifene and tamoxifen had no effect on hip fractures ( 91 ) . Tamoxifen is not approved by the U.S. Food and Drug Administration for the treatment or prevention of osteoporosis . Testosterone No studies reported fracture rates for testosterone . Calcium and Vitamin D In the studies evaluated by MacLean and colleagues ( 5 ) , the evidence for the effect of calcium alone on reduction of fractures is complex . Most studies of pharmacologic agents for osteoporosis include calcium and vitamin D as part of the treatment regimen . Evidence from 1 meta- analysis ( 27 ) and several r and omized trials ( 35 , 48 , 51 , 92 ) showed no significant difference between calcium and placebo in preventing vertebral , nonvertebral , and hip fractures in postmenopausal women . However , nonadherence to therapy may influence this result , and 1 trial with a prespecified analysis of adherent patients found a reduction in fracture risk ( 48 ) . A recent meta- analysis ( 82 ) concluded that the relative risk ( RR ) for fracture with calcium alone was 0.90 ( CI , 0.80 to 1.00 ) , but it did not include a modestly large trial with negative results ( 35 ) . MacLean and colleagues ( 5 ) Objective To evaluate the performance of the QFractureScores for predicting the 10 year risk of osteoporotic and hip fractures in an independent UK cohort of patients from general practice records . Design Prospect i ve cohort study . Setting 364 UK general practice s contributing to The Health Improvement Network ( THIN ) data base . Participants 2.2 million adults registered with a general practice between 27 June 1994 and 30 June 2008 , aged 30 - 85 ( 13 million person years ) , with 25 208 osteoporotic fractures and 12 188 hip fractures . Main outcome measures First ( incident ) diagnosis of osteoporotic fracture ( vertebra , distal radius , or hip ) and incident hip fracture recorded in general practice records . Results Results from this independent and external validation of QFractureScores indicated good performance data for both osteoporotic and hip fracture end points . Discrimination and calibration statistics were comparable to those reported in the internal validation of QFractureScores . The hip fracture score had better performance data for both women and men . It explained 63 % of the variation in women and 60 % of the variation in men , with areas under the receiver operating characteristic curve of 0.89 and 0.86 , respectively . The risk score for osteoporotic fracture explained 49 % of the variation in women and 38 % of the variation in men , with corresponding areas under the receiver operating characteristic curve of 0.82 and 0.74 . QFractureScores were well calibrated , with predicted risks closely matching those across all 10ths of risk and for all age groups . Conclusion QFractureScores are useful tools for predicting the 10 year risk of osteoporotic and hip fractures in patients in the United Kingdom Summary Using FRAX ® , this study aim ed at estimating 10-years probability of osteoporosis (OP)-related fractures and identifies those in need of OP treatment among primary care attendees in Saudi Arabia . Of those aged ≥ 60 years , 14.4 and 18.4 % scored probabilities for major and hip fractures respectively suggesting OP treatment . Predictors for receiving OP screening included the presence of multiple clinical risk factors , occurrence of fragility fractures and physicians recommendation . Purpose This study aim ed at estimating the 10-years probability of osteoporosis (OP)-related fractures and identifying those in need of OP treatment among Saudi adults attending primary care centers ( PHCs ) in Al Hassa , Saudi Arabia , using FRAX ® calculator and to determine factors possibly influence receiving of OP screening among them . Subjects and Methods A total of 1,251 Saudi aged ≥ 40 years , of both genders , were recruited from four urban and three rural r and omly selected PHCs . All were subjected 
    Output:
    
Under current NOGG guidelines , based on age-dependent probability thresholds , inequalities in access to therapy arise especially at older ages ( ≥70 years ) depending on the presence or absence of a prior fracture .
An alternative threshold using a hybrid model reduces this disparity .
Conclusion The use of FRAX ( fixed or age-dependent thresholds ) as the gateway to assessment identifies individuals at high risk more effectively than the use of BMD .