Interrater reliability of the interRAI Acute Care (interRAI AC)

We examined the interrater reliability of the interRAI AC. An observational study was conducted on 3 geriatric wards. Two trained raters completed independently the interRAI AC between 24 and 48 h after admission. A sample of 100 patients (age 84.5 +/- 5.6 years; 45% female) was analyzed. Interrater reliability was tested using observed agreement, kappa coefficients, and intraclass correlation coefficients. The overall kappa median value for nominal items was 0.82 (almost perfect). For items on ordinal level, both the overall weighted kappa median and the intraclass correlation coefficient median were 0.86 (almost perfect). According to conventional cut-offs for interpreting kappa statistics, reliability was almost perfect (K >/= 0.81) for 60% of all items, substantial (0.60 < K