Overdiagnosis of bone fragility in the quest to prevent hip fracture

As Järvinen and colleagues (1) point out hip fractures should be the main target of the fracture prevention in older adults since the consequences of hip fractures, both individually and financially, clearly exceed those of all other age-related fractures combined (2). In other words, any prevention method, whether pharmacological or nonpharmacological, should show its ability to prevent hip fractures to deserve large scale implementation. If this condition is not fulfilled, the method in question is likely to have limited value in ordinary health care settings. Thus, ability to prevent other fractures is of secondary importance, but naturally a welcome additional benefit if there.

As pointed out in several previous responses to Järvinen et al., Cochrane and other reviews have summarized that bisphosphonates (BIS) have very limited value in primary prevention of (hip) fractures. For this reason, the focus and hope have turned towards secondary prevention, in many of the above noted responses, via Fracture Liaison Services (FLS). FLS have been developed and implemented to identify, evaluate and treat older patients with a recent fracture, the treatment clearly having the main focus in the treatment of osteoporosis by BIS, calcium and vitamin D (3-6).

So far so good, but a more detailed evaluation of the study reports (3-6) on FLS effectiveness in fracture prevention reveals a major gap in evidence. Surprisingly, none of the studies was a randomized controlled trial (RCT) thus leaving lots of space for all the well-known biases in the observational non-randomized studies. Most likely, this was the main reason for the huge differences in the results of preventing refractures, from a nonsignificant effect ( 5) to significant, unbelievably high 80% effect (4). This type of results emphasize the urgent need for high-quality RCTs for FLS, especially when IOF and other related organizations are already now, without real evidence base, strongly advocating for worldwide implementation of the FLS.

Pekka Kannus, MD,PhD
UKK Institute
Tampere, Finland

References

1. Järvinen TL, Michaelsson K, Jokihaara J et al. Overdiagnosis of bone fragility in the quest to prevent hip fracture. BMJ 2015;350:h2088.
2. Kanis J, Oden A, Johnell O et al. The burden of osteoporotic fractures: a method for setting intervention thresholds. Osteoporos Int 2001;12:417-427.
3. McLellan AR, Wolowacz SE, Zimovetz EA et al. Fracture liaison services for the evaluation and management of patients with osteoporotic fracture: a cost-effectiveness evaluation based on data collected over 8 years of service provision. Osteoporos Int 2011;22:2083-2098.
4. Lih A, Nandapalan H, Kim M et al. Targeted intervention reduces refracture rates in patients with incident non-vertebral osteoporotic fractures: a 4-year prospective controlled study. Osteoporos Int 2011;22:849-858.
5. Huntjens KBM, van Geel TACM, van den Bergh JPW et al. Fracture liaison service: impact on subsequent nonvertebral fracture incidence and mortality. J Bone Joint Surg (Am) 2014;96:e29(1-8).
6. Nakayama A, Major G, Bogduk N. Comparative refracture rates in hospitals with and without a fracture liaison service: a 6 month historical cohort study. Intern Med J 2015;45(Suppl.2):3.