« Back

Study data confirm extreme old age major factor in increasing mortality after hip fracture

Thursday, October 09 2008 | Comments

---

What's This? Extreme old age as an isolated variable is associated with a higher mortality rate after hip fracture regardless of other confounding variables, a recent study found.

Previous studies have associated advanced age with increased mortality rates after hip fracture, but this finding has not been consistent and the studies have been conducted using small cohorts of patients.

To further investigate, researchers used the Scottish Hip Fracture Audit, a prospective, multicenter study, to collect data from 22 acute care orthopedic units between January 1998 and December 2005. They compared outcomes after hip fracture in extremely elderly patients (n=919) and a control group of younger patients (75 to 89 yrs; n=15,461) who represented the typical hip fracture patient.

Variables were studied in 2 groups: case-mix variables (patient characteristics) and outcome measures. Case-mix variables included age, sex, prefracture mobility, prefracture residence, comorbidity as measured by the American Society of Anesthesiologists (ASA) 28 score, and fracture type. The outcome measures were 30-day and 120-day mortality rates, length of hospital stay, place of residence, and mobility at 120 days. A multivariable logistic regression model was used to compare outcomes between the groups while controlling for the case-mix variables.

Significant case-mix differences were found between the 2 age groups. Extremely elderly patients had higher ASA scores, which indicated a greater degree of comorbidity. Also, they were more likely to live in institutional care and were less likely to be independently mobile. (P<.001).

Thirty-day mortality in the extremely elderly cohort was higher than what was found in the control group (16.8% vs 8.3%); similar findings were observed at 120 days (38.1% vs 21%). In the multivariate analysis that controlled for case-mix variables, the extremely elderly cohort continued to be less likely to survive at both 30 days (OR, 0.52) and 120 days (OR, 0.53).

Among patients who had lived in their own homes before the fracture, only 51% of the surviving extremely elderly patients had returned home at 120 days after admission as compared with 77% of the patients in the control group (odds ratio, 0.36, after adjusting for other case-mix variables).

There was no difference in the total length of hospital stay between the extremely elderly group and the control group (median, 26 days vs 25 days; P=.36).

Study authors concluded that this study data "…confirmed extremely old age is associated with a higher mortality rate [after hip fracture]," outside of other variables.  "This finding has important implications for future resource allocation and service provision in the face of a [rapidly growing] aging population," they added. (Holt G, et al. J Bone Joint Surg Am 2008;90:1899-1905.)

Print  |  E-mail