Liu et al correlated the risk of mortality in the elderly within 1 year of hospital discharge with measures of malnutrition. This can help identify elderly patients who may benefit from nutritional and other interventions. The authors are from the Central Arkansas Veterans Healthcare System and the University of Arkansas.
Patient selection: age >= 65 years and admitted to a VA hospital
Factors associated with mortality in multivariate analysis:
(1) BMI <= 20 kg per meter square
(2) weight as percent of usual weight <= 85%
Other factors correlated with mortality in univariate (but not multivariate) analysis:
(3) > 10% weight loss in the past year
|
Risk Factor |
Adjusted Relative Risk |
95% CI |
|
BMI <= 20 |
1.83 |
1.17 to 2.85 |
|
weight <= 85% of usual body weight |
1.78 |
1.14 to 2.77 |
|
> 10% weight loss |
2.31 |
1.35 to 3.94 |
from Table 3, page M744
where:
• The relative risk adjusted for Katz index of ADL and APACHE II scores.
The authors performed a Cox regression model for survival but did not give details. I have tried to capture the concepts described in the paper using the following model:
|
Parameter |
Finding |
Points |
|
BMI |
> 20 kg per square meter |
0 |
|
|
<= 20 |
1 |
|
weight as percent usual body weight |
> 85% |
0 |
|
|
<= 85% |
1 |
number of risk factors =
= SUM(points for parameters)
Interpretation:
• minimum score: 0
• maximum score: 2
|
Total Score |
Risk for Mortality within 1 Year |
|
0 |
low |
|
1 |
intermediate |
|
2 |
high |
Limitations:
• Since the patients were admitted to a VA hospital, most patients must have been male.
• The mortality rate for a low BMI was 17% at 1 year, while the mortality for a BMI > 20 kg per square meter was 8%, suggesting an appreciable mortality rate in the "low" risk group.
Specialty: Nutrition
