Projects per year
To assess which osmolarity equation best predicts directly measured serum/plasma osmolality and whether its use could add value to routine blood test results through screening for dehydration in older people.
Diagnostic accuracy study
Older people (≥65 years) in 5 cohorts: Dietary Strategies for Healthy Ageing in Europe (NU-AGE, living in the community), Dehydration Recognition In our Elders (DRIE, living in residential care), Fortes (admitted to acute medical care), Sjöstrand (emergency room) or Pfortmueller cohorts (hospitalised with liver cirrhosis).
Reference standard for hydration status:
Directly measured serum/plasma osmolality: current dehydration (serum osmolality >300mOsm/kg), impending/current dehydration (≥295mOsm/kg).
39 osmolarity equations calculated using serum indices from the same blood draw as directly measured osmolality.
Across five cohorts 595 older people were included, of whom 19% were dehydrated (directly measured osmolality >300mOsm/kg). Of 39 osmolarity equations, five showed reasonable agreement with directly measured osmolality and three had good predictive accuracy in subgroups with diabetes and poor renal function. Two equations were characterized by narrower limits of agreement, low levels of differential bias and good diagnostic accuracy in ROC plots (areas under the curve >0.8). The best equation was osmolarity =1.86 × (Na+ + K+) + 1.15 × glucose + urea + 14 (all measured in mmol/L). It appeared useful in people aged ≥65 years with and without diabetes, poor renal function, dehydration, in men and women, with a range of ages, health, cognitive and functional status.
Some commonly used osmolarity equations work poorly, and should not be used. Given costs and prevalence of dehydration in older people we suggest use of the best formula by pathology laboratories using a cutpoint of 295mOsm/L (sensitivity 85%, specificity 59%), to report dehydration risk opportunistically when serum glucose, urea and electrolytes are measured for other reasons in older adults.
- Older adults
- diagnostic accuracy
- 2 Finished
1/01/12 → 31/03/15
Nu-Age: New dietary strategies addressing the specific needs of elderly population for an healthy ageing in Europe
1/05/11 → 30/04/16
- 44 Citations (Scopus)
- 1 Article
Hooper, L., Bunn, D., Downing, A., Jimoh, F., Groves, J., Free, C., Cowap, V., Potter, J., Hunter, P. & Shepstone, L., Oct 2016, In: The Journal of Gerontology: Medical Sciences. 71, 10, p. 1341-1347 7 p.
Research output: Contribution to journal › Article › peer-reviewOpen AccessFile53 Citations (Scopus)50 Downloads (Pure)