Social support and long-term mortality in the elderly: role of comorbidity.
Several studies have demonstrated a global increase in morbidity and mortality in elderly subjects with low social support or high comorbidity. However, the relationship between social support and comorbidity on long-term mortality in elderly people is not yet known. Thus, the present study was performed to evaluate the relationship between social support and comorbidity on 12-year mortality of elderly people. A random sample of 1288 subjects aged 65-95 years interviewed in 1992 was studied. Comorbidity by Charlson Comorbidity Index (CCI) score and Social Support by a scale in which total score ranges from 0 to 17, assigning to lowest social support the highest score, were evaluated. At 12-year follow-up, mortality progressively increase with low social support and comorbidity increasing (from 41.5% to 66.7% and from 41.2% to 68.3%, respectively; p<0.001). Moreover, low social support progressively increases with comorbidity increasing (and 12.4±2.5 to 14.3±2.6; p<0.001). Accordingly, multivariate analysis shows an increased mortality risk of 23% for each increase of tertile of social support scale (Hazard ratio=HR=1.23; 95% CI=1.01-1.51; p=0.045). Moreover, when the analysis was performed considering different degrees of comorbidity we found that social support level was predictive of mortality only in subjects with the highest comorbidity (HR=1.39; 95% CI=1.082-1.78; p=0.01). Thus, low social support is predictive of long-term mortality in the elderly. Moreover, the effect of social support on mortality increases in subjects with the highest comorbidity.
Dipartimento di Medicina Clinica, Scienze Cardiovascolari ed Immunologiche, Cattedra di Geriatria, Università degli Studi di Napoli Federico II, Via S. Pansini, 5, 80131 Napoli, Italy.
Francesca
F
Mazzella
Francesco
F
Cacciatore
Gianluigi
G
Galizia
David
D
Della-Morte
Marianna
M
Rossetti
Rosa
R
Abbruzzese
Assunta
A
Langellotto
Daniela
D
Avolio
Gaetano
G
Gargiulo
Nicola
N
Ferrara
Franco
F
Rengo
Pasquale
P
Abete
D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D016009:Chi-Square Distribution; D002908:Chronic Disease / Q000401:mortality*; D015897:Comorbidity; D004185:Disability Evaluation; D005260:Female; D015577:Geriatric Assessment; D006801:Humans; D007558:Italy / Q000453:epidemiology; D008297:Male; D009026:Mortality / Q000639:trends*; D016016:Proportional Hazards Models; D012307:Risk Factors; D012944:Social Support; D011795:Surveys and Questionnaires; D016019:Survival Analysis