Validity, Reliability, and Insights from Applying the McGill Quality of Life Questionnaire to People Living with Parkinson's Disease (MQoL-PD)

Fatigability and Cardiorespiratory Impairments in Parkinson's Disease: Potential Non-Motor Barriers to Activity Performance

Parkinson's disease (PD) is the second most common neurodegenerative condition after Alzheimer's disease, affecting an estimated 160 per 100,000 people 65 years of age or older. Fatigue is a debilitating non-motor symptom frequently reported in PD, often manifesting prior to disease diagnosis, persisting over time, and negatively affecting quality of life. Fatigability, on the other hand, is distinct from fatigue and describes the magnitude or rate of change over time in the performance of activity (i.e., performance fatigability) and sensations regulating the integrity of the performer (i.e., perceived fatigability). While fatigability has been relatively understudied in PD as compared to fatigue, it has been hypothesized that the presence of elevated levels of fatigability in PD results from the interactions of homeostatic, psychological, and central factors. Evidence from exercise studies supports the premise that greater disturbances in metabolic homeostasis may underly elevated levels of fatigability in people with PD when engaging in physical activity. Cardiorespiratory impairments constraining oxygen delivery and utilization may contribute to the metabolic alterations and excessive fatigability experienced in individuals with PD. Cardiorespiratory fitness is often reduced in people with PD, likely due to the combined effects of biological aging and impairments specific to the disease. Decreases in oxygen delivery (e.g., reduced cardiac output and impaired blood pressure responses) and oxygen utilization (e.g., reduced skeletal muscle oxidative capacity) compromise skeletal muscle respiration, forcing increased reliance on anaerobic metabolism. Thus, the assessment of fatigability in people with PD may provide valuable information regarding the functional status of people with PD not obtained with measures of fatigue. Moreover, interventions that target cardiorespiratory fitness may improve fatigability, movement performance, and health outcomes in this patient population.

Symptom burden among individuals with Parkinson disease: A national survey

Objective

To explore disease burden in Parkinson disease (PD) by evaluating the prevalence of symptoms and key disease milestones (critical events, e.g., hospitalization or frequent falls) and their association with quality of life (QOL) in those with PD.

Methods

We created and pretested an online needs assessment survey to evaluate the clinical characteristics, QOL, symptom prevalence, and critical event frequency among those with PD. We recruited individuals with self-reported Hoehn and Yahr stage II-V PD through online postings and email through the Davis Phinney Foundation. We used logistic regression to evaluate the association between a large number of uncontrolled symptoms and events on QOL.

Results

A total of 612 individuals (mean age 70.1 years, 49.8% women) completed the survey. Among respondents, 13.6% reported poor QOL. Nearly 20% of respondents reported >3 falls, and 15% of respondents had been hospitalized over the previous 6 months. Participants had an average of 5.1 uncontrolled symptoms, with 86.1% of respondents reporting at least 1 uncontrolled symptom; more than 10% of respondents reported >10 uncontrolled symptoms. Depression, confusion, pain, and bothersome hallucinations were associated with poor QOL among the cohort.

Conclusions

In this national survey of individuals with PD, we identified poor QOL, frequent critical events, and numerous uncontrolled symptoms among a substantial proportion of respondents. Although motor symptoms were common, only nonmotor symptoms were associated with poor QOL. Many of these symptoms and events are treatable or preventable, highlighting the need for better identification and management to improve QOL among those with PD.

Measuring quality of life in palliative care for Parkinson's disease: A clinimetric comparison

INTRODUCTION

Quality of life (QOL) assessments allow for more complete evaluation of patients' lived experiences in relation to chronic conditions, such as Parkinson's disease (PD). In palliative care, such instruments are vital to ensure QOL issues are catalogued and addressed for patients. However, little is known regarding the psychometric properties of quality of life scales for use in palliative care for PD, specifically.

METHODS

210 participants with parkinsonian disorders, who participated in a larger palliative intervention clinical trial, completed four quality of life scales (PDQ-39, PROMIS-29, QOL-AD, and McGill QOL) at baseline and post-intervention. Psychometric properties, including internal consistency and concurrent validity, were examined. Factor analyses were performed to evaluate relationships between scale items. Minimal clinically important differences (MCID) and responsiveness were calculated for each scale.

RESULTS

All scales demonstrated good internal consistency and concurrent validity. Factor analyses revealed few deviations from the defined subdomains of the scales. Mean absolute MCID values were estimated at 12.7, 10.9, 3.9, and 18.9 for PDQ-39, PROMIS-29, QOL-AD, and McGill QOL, respectively. The PDQ-39 and PROMIS-29 demonstrated higher responsiveness to palliative intervention, while the QOL-AD was more responsive in the control group.

CONCLUSIONS

The PDQ-39, PROMIS-29, QOL-AD, and McGill QOL are all valid for use in PD palliative care, though subdomains of the scales in this population may differ slightly from those initially defined. We recommend the use of PDQ-39 and PROMIS-29 as outcome measures in clinical trials for palliative care in PD, though the QOL-AD may be superior for tracking disease progression.

Analysis of the prevalence and onset of dysphonia and dysphagia symptoms in movement disorders at an academic medical center

Voice and swallowing impairments are common in movement disorders, but their effect on patients' quality of life is not well known. This study was conducted to determine the onset and prevalence of patient-reported dysphonia and dysphagia symptoms in Parkinson's disease (PD), dystonia, Atypical Parkinsonian Syndromes (APS), and Essential Tremor (ET). Patients referred to a movement disorders clinic in a tertiary care academic medical center completed validated voice and swallowing specific Quality of Life (QOL) questionnaires: Voice Handicap Index-10 (VHI-10) and Eating Assessment Tool-10 (EAT-10). Patient demographics and clinical data were also collected. Two hundred and sixty-eight patients (males = 150, females = 118) completed the questionnaires (n was PD = 103, APS = 30, ET = 56, dystonia = 32, other = 47). Prevalence of patient-reported dysphagia symptoms was significantly higher in APS (63%) than PD (26%), ET (25%), and dystonia (31%). Prevalence of patient-reported dysphonia symptoms was significantly lower in ET (14%) compared to PD (34%) and APS (43%). Disease duration was shorter in PD and APS compared to ET and dystonia (p < 0.05) before reporting clinically significant dysphonia and dysphagia symptoms indicating an earlier onset of these symptoms. There were significant positive correlations between VHI-10 and EAT-10 scores and disease severity, as indicated by Unified Parkinson's Disease motor scores (p < 0.0001) and modified Fahn-Tolosa-Marin Tremor Rating sub-scores (p = 0.0013). Patient-reported dysphonia and dysphagia symptoms were present in one fourth of patients with PD, ET, dystonia, and almost two thirds in APS. Patient-reported QOL measures, such as VHI-10 and EAT-10, can help screen movement disorder patients for dysphonia and dysphagia symptoms.