|Osteoporosis is a disease characterized by dysregulation of bone formation and breakdown leading to more porous bone and greater risk of fracture. Bone quality, not bone quantity is the greatest predictor of osteoporosis-related fracture and is defined as bone mineral density (BMD), the diagnostic measure of bone quality. BMD is calculated as the mass of the bone by the area (g/cm2).BMD accounts for 50-80% of the breaking strength of bones and remains the best predictor of fracture risk. Osteoporosis is the leading cause of fracture in older adults. A reduction of one standard deviation of BMD results in a 1.5-fold increase in relative risk of fracture at most sites and reaches nearly 3-fold in the femoral neck. The most common sites of breaks include the distal radius, vertebrae, pelvis, and femoral neck. Of all osteoporotic fractures, a break of the hip is the most devastating. Within the first six months after a hip fracture, there is a 10-20% risk of mortality and 25-33% within the year in women over 65 years.
The impact factor of journal provides quantitative assessment tool for grading, evaluating, sorting and comparing journals of similar kind. It reflects the average number of citations to recent articles published in science and social science journals in a particular year or period, and is frequently used as a proxy for the relative importance of a journal within its field. It is first devised by Eugene Garfield, the founder of the Institute for Scientific Information. The impact factor of a journal is evaluated by dividing the number of current year citations to the source items published in that journal during the previous two years.