Life span differences after hip fracture – a pilot case control study from primary care in rural Sweden.

Hans Thulesius, Ferdinando Petrazzuoli, Ulrica Mölstad, Anna Segernäs, Pär Wanby, Lisa Alvunger, Robert Eggertsen, Brita Zilg, Håkan Johansson, Anna Lindgren, Nils Larsson, Katarina Walseth Krøgenes, Daniel Albertsson

Keywords: Hip fractures. Excess mortality. Case control study.

Background:

Women in Sweden have a life time hip fracture risk of around 20%, and excess mortality after hip fracture is significant. Yet studies of the excess mortality in terms of lost years of life are rare.

Research questions:

What was the difference in average life span in women who suffered a hip fracture versus age matched women who did not suffer any fragility fractures during their remaining life?

Method:

Pilot case control study. Nested within a population-based fracture prevention study in primary care in rural Sweden, with an 85% participation rate, we recruited as cases 218 women, 70-100 years old at baseline 2001, who had suffered a hip fracture between 2002 and 2024 and were deceased in April 2024. We recruited 2 control participants for every case (n=436) who were alive at the time of the fracture (index timepoint) and did not suffer any fragility fractures during their remaining life until April 2024 when they also were deceased. Control I. was consecutively younger and control II. was consecutively older than the case. Comparisons of mean age was using t-test.

Results:

Mean age at baseline in 2001 was 79.5 years for case participants and 79.7 years for control participants (p=0.8). Median age at hip fracture was 87.8 years (n=218). Mean age at death was 90.9 years (sd 5.0) for the 218 cases and 92.1 years (sd 4.9) for the 436 controls who had no fragility fractures after the index timepoint (p=0.003). Remaining life span was 1 year shorter in cases than in controls (11.4 vs. 12.4 years). Cases lived on average 3 years after the hip fracture.

Conclusions:

In this case control study from rural Sweden we found a 1-year shorter life span after hip fractures in women who were followed from age 80 until their death at 91 (cases) and 92 years (controls).

Points for discussion:

Does it surprise you that average life span after hip fracture was 3 years?

Is excess mortality measured as difference in lifespan a useful measure?

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