Long-term oral bisphosphonate therapy doesn’t seem to give women any extra protection against osteoporotic hip fracture, a new study suggests.

But there’s a hint that staying on the therapy for seven years could be the sweet spot that might spare some women from the morbidity associated with longer term use.

Analysis of hip fracture outcomes for nearly 30,000 US women taking oral bisphosphonates — alendronate, risedronate or ibandronate — backs Australian guidelines that emphasise considering a halt to therapy after five years.

In a bid to fill the evidence gap for continued efficacy of the drugs, US researchers evaluated what happened when women who had been on the drugs for five years either discontinued, continued for another two years or continued for another five years.