Anti-osteoporosis drug use: too little, too much, or just right? The HUNT study, Norway

Use of anti-osteoporotic drugs (AODs) was examined in a Norwegian population 50–85 years. Among them with Fracture Risk Assessment Tool (FRAX) score for major osteoporotic fracture ≥ 20, 25% of the women and 17% of the men received AODs. The strongest predictors for AODs were high age in women and use of glucocorticoids among men.

To examine the use of anti-osteoporotic drugs (AODs) and to identify predictors for prescriptions.

Data were obtained from the Nord-Trøndelag Health Study (HUNT3) performed in 2006–2008 and the Norwegian Prescription Database, including 15,075 women and 13,386 men aged 50–85 years. Bone mineral density (BMD) in the femoral neck was measured in a subgroup of 4538 women and 2322 men. High fracture risk was defined as a FRAX score for major osteoporotic fracture (MOF) ≥ 20%; in the subgroup with BMD, high risk was in addition defined as FRAX_MOF ≥ 20% or T-score ≤ − 2.5. Hazard ratios (HRs) for predictors of incident use of AODs within 2 years after HUNT3 were estimated by Cox’ proportional hazards model.

Among individuals with FRAX MOF ≥ 20%, 25% of the women and 17% of the men were treated with AODs. Among those with FRAX MOF < 20%, 3% and 1% were treated, respectively. In the subgroup with BMD measurement, 24% of the women and 16% of the men at high risk of fractures were treated, compared to 3 and 1% in women and men not fulfilling the criteria. In women, high age was the strongest predictor for treatment (HR 3.84: 95% confidence interval 2.81–5.24), followed by use of glucocorticoids (GCs) (2.68:1.84–3.89). In men, predictors were use of GCs (5.28: 2.70–10.35) followed by multimorbidity (3.16:1.31–7.63). In the subgroup with BMD, T-score ≤ − 2.5 was the strongest predictor (women 3.98:2.67–5.89; men 13.31:6.17–28.74).

This study suggests an undertreatment of AODs in individuals at high risk of fracture.