The Feasibility and Validity of Objective and Patient-Reported Measurements of Cognition During Early Critical Illness Recovery.

BACKGROUND

Cognitive outcomes are an important determinant of quality of life after critical illness, but methods to assess early cognitive impairment and cognition recovery are not established. The objective of this study was to assess the feasibility and validity of objective and patient-reported cognition assessments for generalized use during early recovery from critical illness.

METHODS

Patients presented from the community with acute onset of either intracerebral hemorrhage (ICH) or sepsis as representative neurologic and systemic critical illnesses. Early cognitive assessments comprised the Glasgow Coma Scale (GCS), three NIH Toolbox cognition measures (Flanker Inhibitory Control and Attention Test, List Sorting Working Memory Test and Pattern Comparison Processing Speed Test) and two Patient Reported Outcomes Measurement Information System (PROMIS) cognition measures (Cognition-General Concerns and Cognition-Abilities) performed seven days after intensive care unit discharge or at hospital discharge, whichever occurred first.

RESULTS

We enrolled 91 patients (53 with sepsis, 38 with ICH), and after attrition principally due to deaths, cognitive assessments were attempted in 73 cases. Median [interquartile range] Sequential Organ Failure Assessment scores for patients with sepsis was 7 [3, 11]. ICH cases included 13 lobar, 21 deep and 4 infratentorial hemorrhages with a median [IQR] ICH Score 2 [1, 2]. Patient-reported outcomes were successfully obtained in 42 (58% overall, 79% of sepsis and 34% of ICH) patients but scores were anomalously favorable (median 97th percentile compared to the general adult population). Analysis of the PROMIS item bank by four blinded, board-certified academic neurointensivists revealed a strong correlation between higher severity of reported symptoms and greater situational relevance of the items (ρ = 0.72, p = 0.002 correlation with expert item assessment), indicating poor construct validity in this population. NIH Toolbox tests were obtainable in only 9 (12%) patients, all of whom were unimpaired by GCS (score 15) and completed PROMIS assessments. Median scores were 5th percentile (interquartile range [2nd, 9th] percentile) and uncorrelated with self-reported symptoms. Shorter intensive care unit length of stay was associated with successful testing in both patients with ICH and sepsis, along with lower ICH Score in patients with ICH and absence of premorbid dementia in patients with sepsis (all p < 0.05).

CONCLUSIONS

Methods of objective and patient-reported cognitive testing that have been validated for use in patients with chronic medical and neurologic illness were infeasible or yielded invalid results among a general sample of patients in this study who were in early recovery from neurologic and systemic critical illness. Longer critical illness duration and worse neurocognitive impairments, whether chronic or acute, reduced testing feasibility.