TY - JOUR
T1 - Association of a modified physiologic index with mortality and incident disability: the Health, Aging, and Body Composition study
AU - Sanders, J.L.
AU - Boudreau, R.M.
AU - Penninx, B.W.J.H.
AU - Simonsick, E.M.
AU - Kritchevsky, S.B.
AU - Satterfield, S.
AU - Harris, T.B.
AU - Bauer, D.C.
AU - Newman, A.B.
PY - 2012
Y1 - 2012
N2 - Background.Indexes constructed from components may identify individuals who age well across systems. We studied the associations of a Modified Physiologic Index (systolic blood pressure, forced vital capacity, Digit Symbol Substitution Test score, serum cystatin-C, serum fasting glucose) with mortality and incident disability.Methods.Data are from the Health, Aging, and Body Composition study on 2,737 persons (51.2% women, 40.3% black) aged 70-79 years at baseline and followed on average 9.3 (2.9) years. Components were graded 0 (healthiest), 1 (middle), or 2 (unhealthiest) by tertile or clinical cutpoints and summed to calculate a continuous index score (range 0-10). We used multivariate Cox proportional hazards regression to calculate risk of death or disability and determined accuracy predicting death using the area under the curve.Results.Mortality was 19% greater per index unit (p <. 05). Those with highest index scores (scores 7-10) had 3.53-fold greater mortality than those with lowest scores (scores 0-2). The unadjusted index (c-statistic = 0.656, 95% CI 0.636-0.677, p <. 0001) predicted death better than age (c-statistic = 0.591, 95% CI 0.568-0.613, p <. 0001; for comparison, p <. 0001). The index attenuated the age association with mortality by 33%. A model including age and the index did not predict death better than the index alone (c-statistic = 0.671). Prediction was improved with the addition of other markers of health (c-statistic = 0.710, 95% CI 0.689-0.730). The index was associated with incident disability (adjusted hazard ratio per index unit = 1.04, 95% CI 1.01-1.07).Conclusions.A simple index of available physiologic measurements was associated with mortality and incident disability and may prove useful for identifying persons who age well across systems. © The Author 2012. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved.
AB - Background.Indexes constructed from components may identify individuals who age well across systems. We studied the associations of a Modified Physiologic Index (systolic blood pressure, forced vital capacity, Digit Symbol Substitution Test score, serum cystatin-C, serum fasting glucose) with mortality and incident disability.Methods.Data are from the Health, Aging, and Body Composition study on 2,737 persons (51.2% women, 40.3% black) aged 70-79 years at baseline and followed on average 9.3 (2.9) years. Components were graded 0 (healthiest), 1 (middle), or 2 (unhealthiest) by tertile or clinical cutpoints and summed to calculate a continuous index score (range 0-10). We used multivariate Cox proportional hazards regression to calculate risk of death or disability and determined accuracy predicting death using the area under the curve.Results.Mortality was 19% greater per index unit (p <. 05). Those with highest index scores (scores 7-10) had 3.53-fold greater mortality than those with lowest scores (scores 0-2). The unadjusted index (c-statistic = 0.656, 95% CI 0.636-0.677, p <. 0001) predicted death better than age (c-statistic = 0.591, 95% CI 0.568-0.613, p <. 0001; for comparison, p <. 0001). The index attenuated the age association with mortality by 33%. A model including age and the index did not predict death better than the index alone (c-statistic = 0.671). Prediction was improved with the addition of other markers of health (c-statistic = 0.710, 95% CI 0.689-0.730). The index was associated with incident disability (adjusted hazard ratio per index unit = 1.04, 95% CI 1.01-1.07).Conclusions.A simple index of available physiologic measurements was associated with mortality and incident disability and may prove useful for identifying persons who age well across systems. © The Author 2012. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved.
U2 - https://doi.org/10.1093/gerona/gls123
DO - https://doi.org/10.1093/gerona/gls123
M3 - Article
C2 - 22546961
SN - 1079-5006
VL - 67
SP - 1439
EP - 1446
JO - Journals of Gerontology. Series A: Biological Sciences & Medical Sciences
JF - Journals of Gerontology. Series A: Biological Sciences & Medical Sciences
IS - 12
ER -
