A comparison of clinical risk factors and Bone Mineral Density (BMD) in the assessment of osteoporosis in patients admitted with hip fractures aged fifty years and above at Aga Khan Hospital Dar-es-Salaam, 2009

Date of Award


Document Type


Degree Name

Master of Medicine (MMed)


Family Medicine (East Africa)


Objective: To compare World Health Organisation (WHO) osteoporosis clinical risk factors with BMD in assessing osteoporosis amongst patients over 50 years of age admitted with hip fractures at Aga Khan Hospital, Dar es Salaam


Study Design: Cross-sectional hospital based study.

Study Site: Aga Khan Hospital Dar es Salaam.

Sample Size: 31 patients.

Results: Of the 31 patients with hip fractures studied, 18 (58%) had osteoporosis, 5 (16%) were osteopaenic and 8 (26%) had normal BMD. Odds Ratios for clinical risk factors were non-significant owing to the small sample size and were considered as hypothesis generating rather than confirming or refuting associations. FRAX™ 10 year Major Osteoporotic Fracture Probability > 20% (Model 1) had a sensitivity of 44.44%; specificity of 92.31%; positive LR of 5.78 and negative LR of 0.60. FRAX™ 10 Year Hip Fracture Probability > 3% (Model 2) had a sensitivity of 33.33%; specificity of 92.31%; positive LR of 4.33 and negative LR of 0.72. Test characteristics did not significantly alter when FRAX™ was used with osteoporosis alone in comparison with osteoporosis and osteopaenia combined. Majority of the patients in the study were Asian - Indian. In Black patients with hip fractures 8 out of 12 [66.67%] had osteoporosis. Low energy trauma was the most common cause of fracture proving that fragility fractures were common.

Conclusions and Recommendation: Our study has shown that the prevalence of osteoporosis amongst patients with hip fractures is noteworthy. The FRAX™ tool for osteoporotic fracture determination had appreciable high negative likelihood ratios and specificity. This might enable this tool to be used locally to ‘rule out’ osteoporosis without using BMD. The author recommends further studies that would either determine the incidence of osteoporotic hip fracture in Dar es Salaam hospitals or conduct a community based survey to assess the prevalence of osteoporosis. This study it is hoped would encourage proposals for the development of regional screening protocols for osteoporosis and the development of a region specific FRAX™ model.

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