Clinically diagnosed infections predict disability in activities of daily living among the oldest-old in the general population: The Leiden 85-plus Study

Background: ageing is frequently accompanied by a higher incidence of infections andan increase in disability in activities of daily living (ADL). Objective: this study examines whether clinical infections [urinary tract infections (UTI) and lower respiratory tract infections (LRTI)] predict an increase in ADL disability, stratified for the presenceof ADL disability at baseline (age 86 years). Design: the Leiden 85-plus Study. A population-based prospective follow-up study. Setting: general population. Participants: a totalof 154 men and 319 women aged 86 years. Methods: information on clinical infections was obtained from the medical records. ADL disability was determined at baseline and annually thereafter during 4 years of follow-up, using the 9 ADL items of the Groningen Activity Restriction Scale. Results: in 86-year-old participants with ADL disability, there were nodifferences in ADL increase between participants with and without an infection (-0.32 points extra per year; P = 0.230). However, participants without ADL disability at age 86 years (n = 194; 41%) had an accelerated increase in ADL disability of 1.07 point extra peryear (P < 0.001). For UTIs, this was 1.25 points per year (P < 0.001) and for LRTIs 0.70 points per year (P = 0.041). In this group, an infection between age 85 and 86 yearswas associated with a higher risk to develop ADL disability from age 86 onwards [HR: 1.63(95% CI: 1.04-2.55)]. Conclusions: among the oldest-old in the general population, clinically diagnosed infections are predictive for the development of ADL disability in personswithout ADL disability. No such association was found for persons with ADL disability.