Laboratory results in the elderly: the Sydney Older Persons Study.
BACKGROUND
The use of laboratory intervals based on younger and healthier populations is of questionable validity in older populations. The aim of this study was to examine haematological and biochemical profiles in a sample of community-dwelling older people and to study the impact of age, disease, disability and medications.


METHODS
Basic haematological and biochemical values were obtained for 338 survivors of a random sample of community-living people aged 75 years or over at time of recruitment. These values were compared to the laboratory reference intervals and the effects of age, disease, medication and disability examined.


RESULTS
The distribution of the 35 parameters measured differed from those described by the laboratory reference intervals in all but four of the variables. The values showed few significant age associations but did show associations with disease, disability and drug use.


CONCLUSIONS
Abnormalities identified in haematological and biochemical testing are not due to age but to age-related illnesses. This is contrary to previous studies reporting a change in haematological and biochemical parameters purely on the basis of age. In the presence of abnormalities, identification and clarification of disease states should be made.
Janu
Margaret R
MR
Central Sydney Laboratory Service, Concord Hospital, Concord, NSW 2139, Australia.
Creasey
Helen
H
Grayson
David A
DA
Cullen
John S
JS
Whyte
Scott
S
Brooks
William S
WS
Waite
Louise M
LM
Broe
G Anthony
GA
D000368:Aged; D000369:Aged, 80 and over; D001315:Australia; D001774:Blood Chemical Analysis / Q000706:statistics & numerical data; D002908:Chronic Disease; D004185:Disability Evaluation; D004358:Drug Therapy / Q000706:statistics & numerical data; D015577:Geriatric Assessment / Q000706:statistics & numerical data*; D006801:Humans; D009735:Nursing Homes / Q000706:statistics & numerical data; D012111:Residence Characteristics / Q000706:statistics & numerical data