Disability Trajectories and Serious Fall Injury

Among Medicare beneficiaries, falls account for approximately 10% of emergency department visits and 6% of hospitalizations. Each year, 30% of community-living individuals ≥65 years of age will fall, and among those ≥80 years of age, the incidence increases to 50%.

Researchers have noted that despite the growing amount of research on the natural history of injuries from serious falls, particularly hip fractures, there is little known about the course of disability (functional trajectories) before a fall. In addition, there are few data on the relationship between the functional trajectories and those that follow the fall.

The researchers recently conducted a study to identify distinct sets of functional trajectories in the year immediately prior to and following a serious fall injury. The study was also designed to assess the relationship between the prefall and postfall trajectories, and to determine whether the results differed based on the type of injury (hip fracture vs other serious fall injuries). Results of the study were reported online in JAMA Internal Medicine [doi:10.1001/jamainternmed.2013.9063].

The prospective, cohort study was conducted in greater New Haven, Connecticut, from March 16, 1998, to June 30, 2012. The participants were drawn from an ongoing longitudinal study of 754 community-living persons ≥70 years of age who were initially nondisabled in their basic activities of daily living.

Among the larger study cohort, there were 130 serious fall injuries. Of the 130 injuries, 47.7% (n=62) were hip fractures, 33.1% (n=43) were other fractures (rib, pelvis, other lower extremity, upper extremity, and other), and 19.2% (n=25) were nonfracture injuries (head trauma, lower extremity, upper extremity, and other).

The primary outcome measure of the current study was functional trajectories, based on 13 basic, instrumental, and mobility activities assessed during monthly interviews and identified in the year before and the year after the serious injury.

Among all participants, mean age at the time of hospitalization was 85.9 years, 73.1% were female, 93.1% were white, and 1 in 13 lived in a nursing home. There was no difference in these characteristics according to type of serious fall injury. Prior to the start of the prefall trajectory, 48.5% lived alone, 21.5% had cognitive impairment, 23.1% had depressive symptoms, and 62.3% were physically frail.

Five functional trajectories were identified in the year prior to the serious fall injury: (1) no disability (n=16); (2) mild disability (n=34); (3) moderate disability (n=34); (4) progressive disability (n=23); and (5) severe disability (n=23). Four distinct trajectories were identified after the serious fall injury: (1) rapid recovery (n=12); (2) gradual recovery (n=35); (3) little recovery (n=26); and (4) no recovery (n=57).

For hip fractures as well as other serious fall injuries, the prefall trajectories influenced the postfall trajectories. Rapid recovery was seen only among participants who had no disability or mild disability prior to the fall, and a substantial recovery (rapid or gradual) was highly unlikely among those who had progressive or severe disability prior to the fall.

Postfall trajectories were consistently worse for hip fractures than for the other serious fall injuries.

In summary, the researchers said, “The functional trajectories before and after a serious fall injury are quite varied but highly interconnected, suggesting that the likelihood of recovery is greatly constrained by the prefall trajectory.”