Trends in renal function testing in patients with dementia: a repeated cross-sectional analysis in Australian general practice.

backgroundThere is little published evidence regarding the extent to which renal function testing is performed in older Australians, particularly those with dementia.

objectivesTo examine the prevalence and temporal trends in renal function testing and the factors associated with renal function testing in patients with dementia using Australian general practice data.

methodsTen consecutive cross-sectional analyses were performed to evaluate the proportion of patients aged ≥ 65 years with a recorded diagnosis of dementia, along with matched controls, who had renal function tests using estimated glomerular filtration rate (eGFR) within the twelve months of each year from 2011 to 2020.

resultsBefore matching, 24,701 patients (59.2% females) with, and 72,105 patients (59.2% females) without, a recorded diagnosis of dementia were included. Over the study period, renal function testing increased in both groups, although less for the patients with dementia; from 38.6% (95% CI 37.1-40.0%) in 2011 to 41.9% (95% CI 41-42.9%; p for trend < 0.001) in 2020 in the dementia group, and 49% (95% CI 47.6-50.5%) to 60.4% (95% CI 59.5-61.4%; p for trend < 0.001) in the matched controls. Younger patients with dementia (< 85 years of age), males, and those with more general practitioner visits in the preceding 12 months, hypertension, diabetes, chronic kidney disease, osteoporosis, or pain were most likely to have renal function testing.

conclusionRates of renal function testing in primary care patients with dementia in Australia were significantly lower than for matched controls, and improved only marginally between 2011 and 2020.