The resource utilization in dementia (RUD) instrument is valid for assessing informal care time in community-living patients with dementia

Informal care is a significant component of the societal resource use and costs in dementia care. Thus it is fundamental that assessments of informal care are valid. Thus the aim was to analyse the validity of time estimates with the Resource Utilization in Dementia (RUD) instrument. Prospective observational study. Community sample. Fourteen married and cohabiting patient-caregiver pairs. Comparisons of estimates of caregiver time by recall with the RUD instrument, by diaries and by direct observation, with calculation of agreement statistics for recall vs. diary and recall vs. direct observation to assess accuracy of the time estimates derived from recall. The patients and their caregivers participated in 47 diaries and 30 observation sessions. The agreement between diaries and recall estimates was high for personal ADL (intra-class correlation (ICC) 0.93), supervision (ICC 0.87) and total time (ICC 0.91) and lower but acceptable for instrumental ADL (ICC 0.75). Regarding observation vs recall estimates, the corresponding figures were for personal ADL (ICC 0.81), for instrumental ADL (ICC 0.74), for supervision (ICC 0.78) and for total time (ICC 0.80). The RUD instrument appears to accurately estimate the amount of informal care provided by caregivers to dementia patients.