Age and drug therapy are key prognostic factors for first clinical fracture in patients with primary osteoporosis.
We evaluated the characteristics of 1,142 women and men who attended Canadian osteoporosis clinics and had T-score < or = -2.0 and no prior fractures to determine the predictors of first clinical fracture. Greater age and failure to start osteoporosis drug treatment increased the risk of first clinical fracture.


BACKGROUND
Although risk factors for osteoporotic fractures are well-known, it is unclear which factors predict poor prognosis in patients with primary osteoporosis. The purpose of this study was to determine prognostic factors for first clinical fracture in patients with T-score < or = -2.0 and no previous clinical fracture.


METHODS
We examined prospectively collected data from 1,142 patients aged 40 and over in the Canadian Database of Osteoporosis and Osteopenia. We used prognosis methodology and performed survival analysis to determine factors that increase the risk of first clinical fracture.


RESULTS
Our inception cohort (mean age = 60.6 years, 91% females) had a cumulative fracture incidence of 5.1% (incidence rate: 2.53/100 person-years). Age and osteoporosis drug use predicted incident clinical fractures in multivariable regression analyses. The risk of first fracture increased by 3% per year. Failing to initiate osteoporosis treatment increased fracture risk by 2.4 times. In addition, low physical activity, high body mass index and low T-scores were found to predict fracture risk in certain patient subgroups using tree-structured survival analysis. These findings were robust and did not change with most sensitivity analyses.


CONCLUSIONS
Age and osteoporosis drug treatment are the main prognostic predictors of first clinical fracture in patients with T-score < or = -2.0.
Gajic-Veljanoski
O
O
Osteoporosis Program, University Health Network, Toronto, Canada.
Sebaldt
R J
RJ
Davis
A M
AM
Tritchler
D
D
Tomlinson
G
G
Petrie
A
A
Adachi
J D
JD
Cheung
A M
AM
D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D015519:Bone Density / Q000502:physiology; D050071:Bone Density Conservation Agents / Q000627:therapeutic use; D015444:Exercise / Q000502:physiology; D005260:Female; D005598:Fractures, Spontaneous / Q000209:etiology* / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010024:Osteoporosis / Q000150:complications* / Q000188:drug therapy / Q000503:physiopathology; D015663:Osteoporosis, Postmenopausal / Q000150:complications / Q000188:drug therapy / Q000503:physiopathology; D011379:Prognosis; D011446:Prospective Studies; D012307:Risk Factors; D012737:Sex Factors
D050071:Bone Density Conservation Agents