Predictors of mortality in elderly subjects with obstructive airway disease: the PILE score.
OBJECTIVE
To identify significant covariates in addition to spirometry that predict mortality in elderly subjects with obstructive airway disease (OAD).


METHODS
Two hundred sixty-eight (268) participants with OAD from the Health, Aging and Body Composition study, a community-based observational cohort of well-functioning elderly aged 70-79 years, were followed on average for 6.1 years. Covariates related to pulmonary and physical function, comorbidity, demographics, and three inflammatory markers (interleukin-6, tumor necrosis factor-alpha, C-reactive protein) were evaluated for their association with all-cause mortality (31%) by means of Kaplan Meier analysis and Cox proportional hazards modeling.


RESULTS
Percent predicted forced expiratory volume in one second (PPFEV1; hazard ratio [HR] = 2.03, p < 0.0001), knee extensor strength (HR = 1.36, p = 0.0002), interleukin-6 (HR = 1.37, p = 0.0002) and 400 m corridor walk time (HR = 1.24, p = 0.008) significantly predicted mortality. A multidimensional index, the PILE score, was constructed from PPFEV(1), interleukin-6, and knee extensor strength. Each one-point increase in PILE score (range: 1-10) was associated with a 30% increase in mortality (95% confidence interval: 0.16-0.47) after adjusting for age, race, gender, smoking, and comorbidity, resulting in a 10.4-fold higher risk of death between the highest and lowest risk category.


CONCLUSIONS
Subjects with OAD have a wide gradient of risk for mortality that can potentially be incorporated in clinical decision making.
Department of Pharmaceutical Sciences, University of Tennessee Health Science Center, College of Pharmacy, 874 Union Ave., Memphis, TN 38163, USA.
Nitin
N
Mehrotra
Amado X
AX
Freire
Douglas C
DC
Bauer
Tamara B
TB
Harris
Anne B
AB
Newman
Stephen B
SB
Kritchevsky
Bernd
B
Meibohm
D000368:Aged; D000369:Aged, 80 and over; D015897:Comorbidity; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D010414:Pennsylvania / Q000453:epidemiology; D016016:Proportional Hazards Models; D029424:Pulmonary Disease, Chronic Obstructive / Q000401:mortality*; D018570:Risk Assessment / Q000379:methods; D012307:Risk Factors; D012720:Severity of Illness Index; D013714:Tennessee / Q000453:epidemiology