***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: Abstract : To examine the risk of mortality following all clinical fractures , we followed 6459 women age 55–81 years participating in the Fracture Intervention Trial for an average of 3.8 years . All fractures and deaths were confirmed by medical record or death certificate . Clinical fractures were fractures that came to medical attention . Fracture status was used as a time-dependent covariate in proportional hazards models . The 907 women who experienced a fracture were older , had lower bone mineral density and were more likely to report a positive fracture history . A total of 122 women died  over the course of the study with 23 of these deaths occurring after a clinical fracture . The age-adjusted relative risk ( 95 % confidence intervals ) of dying following a clinical fracture was 2.15 ( 1.36 , 3.42 ) . This primarily reflected the higher mortality following a hip fracture , 6.68 ( 3.08 , 14.52 ) ; and clinical vertebral fracture , 8.64 ( 4.45 , 16.74 ) . Results were similar after adjusting for treatment assignment , health status and specific common comorbidities . There was no increase in mortality following a forearm or other fracture ( non-hip , non-wrist , non-vertebral fracture ) . In conclusion , clinical vertebral fractures and hip fractures are associated with a substantial increase in mortality among a group of relatively healthy older women We examined the effect of alendronate treatment for 3 - 4 yr on risk of new fracture among 3658 women with osteoporosis enrolled in the Fracture Intervention Trial . This cohort included women with existing vertebral fracture and those with osteoporosis as defined by T score of less than -2.5 at the femoral neck but without vertebral fracture . All analyses were prespecified in the data analysis plan . The magnitudes of reduction of fracture incidence with alendronate were similar in both groups . The two groups were , therefore , pooled to obtain a more precise estimate of the effect of alendronate on relative risk of fracture ( relative risk , 95 % confidence interval ) : hip ( 0.47 , 0.26 - 0.79 ) , radiographic vertebral ( 0.52 , 0.42 - 0.66 ) , clinical vertebral ( 0.55 , 0.36 - 0.82 ) , and all clinical fractures ( 0.70 , 0.59 - 0.82 ) . Reductions in risk of clinical fracture were statistically significant by 12 months into the trial . We conclude that reductions in fracture risk during treatment with alendronate are consistent in women with existing vertebral fractures and those without such fractures but with bone mineral density in the osteoporotic range . Furthermore , reduction in risk is evident early in the course of treatment . This pooled analysis provides a more precise estimate of the antifracture efficacy of alendronate in women with osteoporosis than that in prior reports The present study describes the biological effects of risedronate , a pyridinyl bisphosphonate , on bone and assesses the safety and tolerability of risedronate when given at high doses , with or without calcium , to postmenopausal women with spinal osteoporosis . This single-center descriptive , double-blind , placebo-controlled , r and omized , parallel group study included 32 postmenopausal white women with at least one radiographically confirmed vertebral compression fracture . Patients were r and omized to one of four different dose regimen groups : ( i ) R-P , risedronate 20 mg/day for 14 days , followed by placebo for 42 days ; ( ii ) R-CP-P , risedronate 20 mg/day for 14 days , followed by elemental calcium 1000 mg/day and placebo for 14 days , then by placebo for 28 days ; ( iii ) R-CP-R-CP , risedronate 20 mg/day for 7 days , followed by elemental calcium 1000 mg/day and placebo for 21 days , then risedronate 20 mg/day for 7 days , and finally elemental calcium 1000 mg/day and placebo for 21 days ; and ( iv ) P , placebo for 56 days . The biological response was investigated by measuring serum calcium , parathyroid hormone ( PTH ) , and 2 h urinary pyridinoline/creatinine ( Pyr/Cr ) and deoxypyridinoline/creatinine ( DPyr/Cr ) ratios at baseline and at days 3 , 7 , 14 , 21 , 28 , 35 , 42 , 49 , 56 , and 84 . Overall , there were no consistent trends observed between the active group and placebo for serum calcium . In groups R-P , R-CP-P , and R-CP-R-CP , mean serum PTH levels were elevated above baseline values for the entire 56 day treatment period and remained elevated , although to a lesser extent , at the day 84 follow-up visit . The effect of calcium supplementation on PTH was variable . Urinary Pyr/Cr and DPyr/Cr ratios were decreased from baseline over the entire study period in all groups receiving risedronate . The maximum observed percent decreases from baseline for Pyr/Cr and DPyr/Cr were -46.9 % and -58.8 % , respectively , at day 49 in the R-CP-R-CP group . In conclusion , risedronate given orally at a dose of 20 mg/day , continuously for 7 or 14 days , result ed in the expected biological response in osteoporotic women . The time course of changes in PTH levels following cessation of dosing was unaffected by calcium supplementation . There was no evidence of a PTH-mediated rebound in bone resorption following cessation of therapy . Furthermore , based on collagen cross-link data , patients did not show an excessive reduction in bone turnover Vertebral fracture prevalence was assessed in an age-stratified r and om sample of Rochester , Minnesota women aged 50 years and over . Vertebral fractures , including wedge and concavity as well as compression fractures , were common and increased with age . The estimated incidence of new vertebral fractures also rose with age , reaching 29.6 per 1,000 person-years in women aged greater than or equal to 85 years . The prevalence of one or more vertebral fractures also increased with declining bone mass , reaching 42 % in women with spinal bone mineral density less than 0.6 g/cm2 by dual photon absorptiometry . Bone mass and age contributed independently to the risk of vertebral fracture , but " age " may reflect other manifestations of osteoporosis 
    Output:
    
However , observational data has led to concerns regarding the potential risk for upper gastrointestinal injury and , less commonly , osteonecrosis of the jaw .
AUTHORS ' CONCLUSIONS At 5 mg/day a statistically significant and clinical ly important benefit in the secondary prevention of vertebral , non-vertebral and hip fractures was observed , but not for wrist .
There were no statistically significant reductions in the primary prevention of vertebral and non-vertebral fractures .