Predictors of Loss of Functional Independence in Parkinson's Disease: Results from the COPPADIS Cohort at 2-Year Follow-Up and Comparison with a Control Group

Abstract

Background and objective: The aim of this study was to compare the progression of independence in activities of daily living (ADL) in Parkinson's disease (PD) patients versus a control group, as well as to identify predictors of disability progression and functional dependency (FD).

Patients and methods: PD patients and control subjects, who were recruited from 35 centers of Spain from the COPPADIS cohort between January 2016 and November 2017 (V0), were included. Patients and subjects were then evaluated again at the 2-year follow-up (V2). Disability was assessed with the Schwab & England Activities of Daily Living Scale (S&E-ADLS) at V0 and V2. FD was defined as an S&E-ADLS score less than 80%.

Results: In the PD group, a significant decrease in the S&E-ADLS score from V0 to V2 (N = 507; from 88.58 ± 10.19 to 84.26 ± 13.38; p < 0.0001; Cohen's effect size = -0.519) was observed but not in controls (N = 124; from 98.87 ± 6.52 to 99.52 ± 2.15; p = 0.238). When only patients considered functional independent at baseline were included, 55 out of 463 (11.9%) converted to functional dependent at V2. To be a female (OR = 2.908; p = 0.009), have longer disease duration (OR = 1.152; p = 0.002), have a non-tremoric motor phenotype at baseline (OR = 3.574; p = 0.004), have a higher score at baseline in FOGQ (OR = 1.244; p < 0.0001) and BDI-II (OR = 1.080; p = 0.008), have a lower score at baseline in PD-CRS (OR = 0.963; p = 0.008), and have a greater increase in the score from V0 to V2 in UPDRS-IV (OR = 1.168; p = 0.0.29), FOGQ (OR = 1.348; p < 0.0001) and VAFS-Mental (OR = 1.177; p = 0.013) (adjusted R-squared 0.52; Hosmer and Lemeshow test = 0.94) were all found to be independent predictors of FD at V2.

Conclusions: In conclusion, autonomy for ADL worsens in PD patients compared to controls. Cognitive impairment, gait problems, fatigue, depressive symptoms, more advanced disease, and a non-tremor phenotype are independent predictors of FD in the short-term.

Keywords: Parkinson’s disease; activities of daily living; dependency; disability; gait.

Figure 1

Change in S&E-ADLS score from V0 to V2 in controls (left) and PD patients (right). S&E-ADLS score at V0 in PD vs. controls, * p < 0.0001 (Mann–Whitney–Wilcoxon test); S&E-ADLS score at V2 in PD vs. controls, p < 0.0001 (Mann–Whitney–Wilcoxon test); S&E-ADLS score at V2 vs. S&E-ADLS score at V0 in controls, p = 0.238 (GLM repeated measure adjusted to age and gender); S&E-ADLS score at V2 vs. S&E-ADLS score at V0 in PD patients, p < 0.0001 (GLM repeated measure adjusted to age, gender, LEDD at V0 and LEDD at V2). PD, Parkinson’s disease; S&E-ADLS, Schwab & England Activities of Daily Living Scale.

Figure 2

(A) Frequency of PD patients and controls presenting functional dependency (S&E-ADLS score < 80%) at V0 and at V2. p-values < 0.0001 for functional dependency in PD patients at V2 vs. at V0, in PD patients at V0 vs. in controls at V0, and in PD patients at V2 vs. in controls at V0; (B) frequency of PD patients (N = 507; in grey) and controls (N = 124; in blue) presenting different scores in the S&E-ADLS at V0 (baseline) and at V2 (2 years ± 30 days). PD, Parkinson’s disease; S&E-ADLS, Schwab & England Activities of Daily Living Scale.

Figure 3

Predictors of functional disability (S&E-ADLS score < 80%) at V2. Light grey arrows show the OR of variables from baseline visit (V0). Dark grey arrows show the OR of change of variables from V0 to V2. Red arrows with discontinue line represent the 95%CI. BDI-II, Beck Depression Inventory-II; DD, disease duration; FOGQ, Freezing Of Gait Questionnaire; PD-CRS, Parkinson’s Disease Cognitive Rating Scale; VAFS, Visual Analog Fatigue Scale.