Purpose: To assess the association between dehydration and ethnicity in older adults; and to determine if diuretic use can help explain the disparity between blacks and whites in diagnosis of dehydration.
Methods: We conducted a case-control study in black and white older adults in a pharmaceutical assistance program who were hospitalized during 1997. Cases were all those diagnosed with dehydration (N=9186). Randomly selected controls were 4:1 frequency matched to cases by sex and age group (N(Total)=45585).
Results: Patients taking loop, potassium-sparing, thiazide or combination diuretics were more likely to have a diagnosis of dehydration. Dehydration diagnosis was associated with being black (odds ratio (OR)=1.49, 95% confidence interval (CI), 1.36-1.63, p<.001), independent of diuretic use or dosage. That association remained when examining loop (OR=1.36, 95% CI, 1.10-1.63, p<.004) and thiazide diuretic users (OR=1.59, 95% CI, 1.09-2.34, p=.017), but not potassium-sparing or combination diuretic users.
Conclusion: Diuretic use is significantly associated with dehydration diagnosis, but the greater likelihood of older blacks being diagnosed with dehydration is independent of diuretic use. The increased risk of morbidity and mortality associated with dehydration suggests that further examination of the root cause of this disparity in risk is warranted.