Language impairment in adults with end-stage liver disease: application of natural language processing towards patient-generated health records

Lindsay K Dickerson,Anthony L Guerrerio,Po-Hung Chen,Mara A Mcadams-Demarco,Masoud Rouhizadeh,Douglas B Mogul,Mary Grace Bowring,Allan B Massie,Dorry L Segev,Yelena Korotkaya,Benjamin N Philosophe,Alicia Cannon

doi:10.1038/s41746-019-0179-9

Lindsay K Dickerson, Anthony L Guerrerio + Show 10 more

Open Access

https://doi.org/10.1038/s41746-019-0179-9

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Abstract

End-stage liver disease (ESLD) is associated with cognitive impairment ranging from subtle alterations in attention to overt hepatic encephalopathy that resolves after transplant. Natural language processing (NLP) may provide a useful method to assess cognitive status in this population. We identified 81 liver transplant recipients with ESLD (4/2013–2/2018) who sent at least one patient-to-provider electronic message pre-transplant and post-transplant, and matched them 1:1 to “healthy” controls—who had similar disease, but had not been evaluated for liver transplant—by age, gender, race/ethnicity, and liver disease. Messages written by patients pre-transplant and post-transplant and controls was compared across 19 NLP measures using paired Wilcoxon signed-rank tests. While there was no difference overall in word length, patients with Model for End-Stage Liver Disease Score (MELD) ≥ 30 (n = 31) had decreased word length in pre-transplant messages (3.95 [interquartile range (IQR) 3.79, 4.14]) compared to post-transplant (4.13 [3.96, 4.28], p = 0.01) and controls (4.2 [4.0, 4.4], p = 0.01); there was no difference between post-transplant and controls (p = 0.4). Patients with MELD ≥ 30 had fewer 6+ letter words in pre-transplant messages (19.5% [16.4, 25.9] compared to post-transplant (23.4% [20.0, 26.7] p = 0.02) and controls (25.0% [19.2, 29.4]; p = 0.01). Overall, patients had increased sentence length pre-transplant (12.0 [9.8, 13.7]) compared to post-transplant (11.0 [9.2, 13.3]; p = 0.046); the same was seen for MELD ≥ 30 (12.3 [9.8, 13.7] pre-transplant vs. 10.8 [9.6, 13.0] post-transplant; p = 0.050). Application of NLP to patient-generated messages identified language differences—longer sentences with shorter words—that resolved after transplant. NLP may provide opportunities to detect cognitive impairment in ESLD.

Highlights

End-stage liver disease (ESLD) is associated with a wide spectrum of neurocognitive impairment ranging from minimal alterations in attention, working memory, and psychomotor speed to coma and death.[1,2,3] Approximately 80% of patients with ESLD have neurocognitive changes associated with poorer quality of life, including deteriorating sleep and work performance
Given the absence of precise diagnosis and substantial mortality risk associated with late-stage encephalopathy, there exists a need for a real-time and determinate means to identify ESLD-related cognitive impairment
One study demonstrated that patients with minimal HE (MHE) had deficits in verbal fluency and phrase construction that resolved after transplantation, while other research has concluded that language remains largely intact.[16,17]

Summary

Introduction

End-stage liver disease (ESLD) is associated with a wide spectrum of neurocognitive impairment ranging from minimal alterations in attention, working memory, and psychomotor speed to coma and death.[1,2,3] Approximately 80% of patients with ESLD have neurocognitive changes associated with poorer quality of life, including deteriorating sleep and work performance. Among patients with MELD ≥ 30, words were on average shorter in pre-transplant messages (3.95 [3.79, 4.14]) compared to post-transplant (4.13 [3.96, 4.28]; p = 0.01) and controls (4.2 [4.0, 4.4]; p = 0.01) (Table 3).

Results

Conclusion