Association between non-motor symptoms and health-related quality of life for patients with Parkinson’s disease: Evidence from a smartphone-based survey

Abstract Background This study aims to explore the association between the total number of non-motor symptoms and the Parkinson’s disease (PD) patients’ health-related quality of life quantitatively, using data from one of the largest smartphone-powered studies and a simplified version of 8-item Parkinson’s disease Quality of life Questionnaire (PDQ-8). Methods The data used for analysis constitutes one part of a dataset derived from the project named ‘100 for Parkinson’s’, an initiative of uMotif in conjunction with the Cure Parkinson’s Trust, Parkinson’s UK and the European Parkinson’s Disease Association. 1246 patients were included in the baseline survey. The 30-item Non-Motor Symptom (NMS-30) Questionnaire and PDQ-8 Summary Index (PDQ-8 SI) were used to measure health-related quality of life and a generalized linear model was used to analyze the association of the non-motor symptoms and quality of life. Results The mean number of NMS per patient was 11.81 ± 5.53. For patients with limited ability to work: the key symptoms were urgency (77.4%), sad or blue (71.05%) and difficulty getting to sleep or staying asleep (70.90%). After controlling for the life-style determinants and psychological symptoms prior PD diagnosis determinants, GLM presented the total sum of NMS-30 questions had the strongest positive influence on health-related quality of life as measured by the PDQ-8 SI. Where the sum of NMS scores increases by 1 point, the PDQ-8 SI will increase by 1.33 points (95%CI: 1.13, 1.52; P < 0.001). For patients without limited ability to work: urgency (62.45%), difficulty getting to sleep or staying asleep (59.81%) and getting up regularly at night to pass urine (55.09%) were the most frequent symptoms. GLM showed that where the total sum of NMS scores increases by 1 point, the PDQ-8 SI will increase by 1.56 points (95%CI: 1.37, 1.76; P < 0.001) after controlling for other confounders. Conclusions This smartphone-based study finds a higher total number of non-motor symptoms is related to a lower health-related quality of life for PD patients. It provides useful evidence for the PDQ-8 instrument and is helpful for a multidisciplinary approach to patient care and facilitate the provision of more comprehensive education for patients and caregivers.