Association Between Restricting Symptoms and Disability After Critical Illness Among Older Adults

Abstract

Objectives: Older adults who survive critical illness are at risk for increased disability, limiting their independence and quality of life. We sought to evaluate whether the occurrence of symptoms that restrict activity, that is, restricting symptoms, is associated with increased disability following an ICU hospitalization.

Design: Prospective longitudinal study of community-living adults 70 years old or older who were interviewed monthly between 1998 and 2018.

Setting: South Central Connecticut, United States.

Patients: Two hundred fifty-one ICU admissions from 202 participants who were discharged alive from the hospital.

Interventions: None.

Measurements and main results: Occurrence of 15 restricting symptoms (operationalized as number of symptoms and presence of ≥ 2 symptoms) and disability in activities of daily living, instrumental activities of daily living, and mobility was ascertained during monthly interviews throughout the study period. We constructed multivariable Poisson regression models to evaluate the association between post-ICU restricting symptoms and subsequent disability over the 6 months following ICU hospitalization, adjusting for known risk factors for post-ICU disability including pre-ICU disability, frailty, cognitive impairment, mechanical ventilation, and ICU length of stay. The mean age of participants was 83.5 years ( sd , 5.6 yr); 57% were female. Over the 6 months following ICU hospitalization, each unit increase in the number of restricting symptoms was associated with a 5% increase in the number of disabilities (adjusted rate ratio, 1.05; 95% CI, 1.04-1.06). The presence of greater than or equal to 2 restricting symptoms was associated with a 29% greater number of disabilities over the 6 months following ICU hospitalization as compared with less than 2 symptoms (adjusted rate ratio, 1.29; 95% CI, 1.22-1.36).

Conclusions: In this longitudinal cohort of community-living older adults, symptoms restricting activity were independently associated with increased disability after ICU hospitalization. These findings suggest that management of restricting symptoms may enhance functional recovery among older ICU survivors.

Figure 1.

Number of restricting symptoms and disabilities in the month before and six months after ICU hospitalization. On the x-axis, the month before hospitalization is denoted by −1. Bars represent standard errors for the mean number of restricting symptoms and disabilities. The number of observations from ICU survivors at each assessment during months 1 to 6 following ICU hospitalization was 251, 251, 238, 228, 218, and 212.

Figure 2.

Predicted mean number of disabilities for those with and without multiple restricting symptoms. Bars represent 95% confidence intervals. As described in the Methods, the estimates were obtained using generalized estimating equations (GEE) to model the number of disabilities every month over the six months following ICU hospitalization as a Poisson outcome. Covariates included age, sex, enrollment in fee-for-service Medicare, race and ethnicity, frailty, cognitive impairment, depression, number of disabilities in the month preceding ICU hospitalization, use of mechanical ventilation, length of ICU stay, time since the prior comprehensive assessment, and number of the specific 18-month interval. aRR = adjusted Rate Ratio.