The Low Fall as a Surrogate Marker of Frailty Predicts Long-Term Mortality in Older Trauma Patients.
BACKGROUND
Frailty is associated with adverse outcomes including disability, mortality and risk of falls. Trauma registries capture a broad range of injuries. However, frail patients who fall comprise a large proportion of the injuries occurring in ageing populations and are likely to have different outcomes compared to non-frail injured patients. The effect of frail fallers on mortality is under-explored but potentially significant. Currently, many trauma registries define low falls as less than three metres, a height that is likely to include non-frailty falls. We hypothesized that the low fall from less than 0.5 metres, including same-level falls, is a surrogate marker of frailty and predicts long-term mortality in older trauma patients.


METHODS
Using data from the Singapore National Trauma Registry, 2011-2013, matched till September 2014 to the death registry, we analysed adults aged over 45 admitted via the emergency department in public hospitals sustaining blunt injuries with an injury severity score (ISS) of 9 or more, excluding isolated hip fractures from same-level falls in the over 65. Patients injured by a low fall were compared to patients injured by high fall and other blunt mechanisms. Logistic regression was used to analyze 12-month mortality, controlling for mechanism of injury, ISS, revised trauma score (RTS), co-morbidities, gender, age and age-gender interaction. Different low fall height definitions, adjusting for injury regions, and analyzing the entire adult cohort were used in sensitivity analyses and did not change our findings.


RESULTS
Of the 8111 adults in our cohort, patients who suffered low falls were more likely to die of causes unrelated to their injuries (p<0.001), compared to other blunt trauma and higher fall heights. They were at higher risk of 12-month mortality (OR 1.75, 95% CI 1.18-2.58, p = 0.005), independent of ISS, RTS, age, gender, age-gender interaction and co-morbidities. Falls that were higher than 0.5m did not show this pattern. Males were at higher risk of mortality after low falls. The effect of age on mortality started at age 55 for males, and age 70 for females, and the difference was attributable to the additional mortality in male low-fallers.


CONCLUSIONS
The low fall mechanism can optimize prediction of long-term mortality after moderate and severe injury, and may be a surrogate marker of frailty, complementing broader-based studies on aging.
Singapore General Hospital, Singapore, Singapore; Duke-National University of Singapore, Singapore, Singapore.
Ting Hway
TH
Wong
Duke-National University of Singapore, Singapore, Singapore.
Hai V
HV
Nguyen
Tan Tock Seng Hospital, Singapore, Singapore.
Ming Terk
MT
Chiu
Health Promotion Board, Singapore, Singapore.
Khuan Yew
KY
Chow
Singapore General Hospital, Singapore, Singapore; Duke-National University of Singapore, Singapore, Singapore.
Marcus Eng Hock
ME
Ong
Health Promotion Board, Singapore, Singapore.
Gek Hsiang
GH
Lim
Duke-National University of Singapore, Singapore, Singapore.
Nivedita Vikas
NV
Nadkarni
Duke-National University of Singapore, Singapore, Singapore.
Dianne Carrol Tan
DC
Bautista
Tan Tock Seng Hospital, Singapore, Singapore.
Jolene Yu Xuan
JY
Cheng
National University Hospital System, Singapore, Singapore.
Lynette Mee Ann
LM
Loo
Singapore General Hospital, Singapore, Singapore.
Dennis Chuen Chai
DC
Seow
D000058:Accidental Falls / Q000401:mortality*; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers; D015897:Comorbidity; D004636:Emergency Service, Hospital; D005260:Female; D050723:Fractures, Bone / Q000401:mortality; D006801:Humans; D015601:Injury Severity Score; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D012042:Registries; D012846:Singapore; D014193:Trauma Centers; D014949:Wounds, Nonpenetrating / Q000401:mortality
D015415:Biomarkers