Risk of hip fracture in protected and unprotected falls in nursing homes in Norway.(Original Article)

Objectives: To compare the probability of hip fracture in protected and unprotected falls in a real world setting in nursing homes.

Design: Observational study.

Setting: Seventeen nursing homes (965 beds) in Norway.

Subjects: All residents in the nursing homes with at least one fall during the intervention period.

Intervention: Hip protectors were introduced as a regular part of the health care service for all the residents for an intervention period of 18 months. Residents who were considered high risk were especially encouraged to be regular users of hip protectors.

Main outcome measures: Hip fracture in protected and unprotected falls.

Results: At the time of the first fall within each faller, 430 were non-users of hip protectors, while 84 were registered as users, but did not wear it, and 191 were users and did wear it. The odds ratio of suffering a hip fracture was 0.31, 95% confidence interval 0.13 to 0.75 for wearers compared with non-wearers in the first fall, adjusted for age, gender, and whether they were registered as users or not.

Conclusion: The odds of suffering a hip fracture for nursing home high risk residents was reduced to less than a third in protected falls compared with unprotected falls. Or, in other words, the odds of hip fracture showed a 69% reduction in protected falls compared with unprotected falls.

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Injury Prevention 2004;10:16-20. doi: 10.1136/ip.2003.003889

Almost 100% of hip fractures are the result of a fall. (1) (2) Since 1993 several studies have shown that an external hip protector can prevent many hip fractures in high risk groups, (3-5) but its protection is not necessarily 100%. (2) (6) (7) When a person is so osteoporotic that the hip can break just by walking, or the person falls backward, the hip protector cannot protect effectively against hip fracture. The majority of patients with hip fracture (76%), however, seem to fall directly to the side, (2) and a fracture might then be prevented by use of a hip protector.

The present paper is the second from a hip protector intervention project in Norway. The first paper dealt with the reduction of incidence of hip fracture (an intention to treat analysis (6) ), while this second paper deals with protected and unprotected falls. The intervention project took place in two municipalities outside Oslo (Asker and Baerum). Hip protectors were introduced as a regular part of the health care service for all residents in 17 nursing homes for an intervention period of 18 months. In the first paper an external and independent evaluation showed a 39% reduction in the incidence of hip fracture in these nursing homes during the intervention period compared with an 18 month pre-intervention period. (6)

The results from this project, as well as other hip protector intervention studies, are dependent on both patient compliance in the intervention group and on the real effect of the hip protector in a given fall. In addition the results will be dependent on the degree to which the user group of the hip protector contains most of the high risk people in the intervention group. In the Asker/Baerum project the intervention group contained both high risk and low risk individuals--that is, all the residents were offered hip protectors. (6) Knowledge about the ability of the hip protector to reduce the incidence of hip fracture in a high risk group is important and interesting for health care authorities. This is the case irrespective of whether the hip fracture decrease is due mainly to good compliance and/or good protective effect in a given fall. However, for a high risk person and his or her doctor it is also interesting to know how effectively the hip protector protects against hip fracture in a given fall.

The aim of this second paper from the Asker/Baerum project was therefore to compare the probability of hip fracture in protected and unprotected falls among the fallers in nursing homes where all the residents were offered hip protectors.

METHODS

Study design and intervention

The data from the Asker/Baerum project, the implementation of the hip protector in the 17 nursing homes (965 beds), and the registration of hip fractures (that is, fractura colli femoris and fractura pertrochanterica) in the nursing homes during the 18 month intervention period have been described elsewhere. (6) During the…