The Clinical Frailty Scale predicts inpatient mortality in older hospitalised patients with idiopathic Parkinson's disease

Abstract

Parkinson's disease and frailty are both common conditions affecting older people. Little is known regarding the association of the Clinical Frailty Scale with hospital outcomes in idiopathic Parkinson's disease patients admitted to the acute hospital. We aimed to test whether frailty status was an independent predictor of short-term mortality and other hospital outcomes in older inpatients with idiopathic Parkinson's disease.

Method: We conducted an observational retrospective study in a large tertiary university hospital between October 2014 and October 2016. Routinely measured patient characteristics included demographics (age and sex), Clinical Frailty Scale, acute illness severity (Emergency Department Modified Early Warning Score), the Charlson Comorbidity Index, discharge specialty, history of dementia, history of depression and the presence of a new cognitive impairment. Outcomes studied were inpatient mortality, death within 30 days of discharge, new institutionalisation, length of stay ≥ 7 days and readmission within 30 days to the same hospital.

Results: There were 393 first admission episodes of idiopathic Parkinson's disease patients aged 75 years or more; 166 (42.2%) were female. The mean age (standard deviation) was 82.8 (5.0) years. The mean Clinical Frailty Scale was 5.9 (1.4) and the mean Charlson Comorbidity Index was 1.3 (1.5). After adjustment for covariates, frailty and acute illness severity were independent predictors of inpatient mortality; odds ratio for severely/very severely frail or terminally ill = 8.1, 95% confidence interval 1.0-63.5, p = 0.045 and odds ratio for acute illness severity: 1.3, 95% confidence interval 1.1-1.6, p = 0.005). The Clinical Frailty Scale did not significantly predict other hospital outcomes.

Conclusions: The Clinical Frailty Scale was a significant predictor of inpatient mortality in idiopathic Parkinson's disease patients admitted to the acute hospital and it may be useful as a marker of risk in this vulnerable population.

Keywords: Clinical Frailty Scale; Parkinson’s disease; hospital outcomes.