A SYSTEMATIC REVIEW AND META-REGRESSION ANALYSIS OF THE RELATIONSHIP BETWEEN PHYSICAL AND PSYCHOLOGICAL SYMPTOMS IN INDIVIDUALS WITH PARKINSON'S DISEASE

P. Hodgson^1,2, A. Jordan¹, C. Sinani¹, D. Charura¹

¹York St John University, York, United Kingdom, ²Tees, Esk and Wear Valleys NHS Foundation Trust, Durham, United Kingdom

Background: It is widely recognized that individuals with Parkinson’s Disease (PD) can experience both physical and psychological symptoms such as tremor, muscle stiffness, anxiety, depression, and apathy. However, the relationship between physical and psychological symptoms is poorly understood and appears to be rarely acknowledged in current literature. Considering any potential relationship between physical and psychological symptoms should improve our understanding of the condition and may translate to improved symptom management and outcomes for patients.

Purpose: The primary aim of this review was to examine available literature reporting outcomes for both physical and psychological symptoms in individuals with PD, with the secondary aim of completing meta-regression analysis to quantify possible relationships, where appropriate.

Methods: The review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Systematic searches of four databases (MEDLINE, CINAHL, AMED, and APA PsychInfo) were completed, identifying studies published before 22/10/2021 (PROSPERO CRD42021281392). Studies were screened against pre-defined inclusion and exclusion criteria, with included studies reporting objective findings from physical and psychological assessments commonly used in clinical and research settings. Abstract and full-text screening was completed in two stages by two reviewers independently. Quality and risk of bias was assessed using the EPHPP Quality Assessment Tool for Quantitative Studies. Disagreements were resolved through discussion and, if necessary, by a third reviewer. Quantitative baseline measures for the pre-defined physical and psychological outcome measures were extracted and meta-regression analysis of the relationship between variables completed using R, where appropriate.

Results: Of the 1175 studies retrieved, 27 (13 Randomized Controlled Trials, 4 Clinical Control Trials, 6 Cohorts, 2 Cohort Analytic Studies, 1 Case Control Study and 1 Other) were selected for analysis. A total of 1211 PD participants from 9 countries were assessed utilizing a range of physical and psychological measures. Study quality was high (n=9), moderate (n=10), and weak (n=8) with downgrading of quality most commonly due to possible selection bias, and potential confounding variables not being accounted for. None of the included studies considered or assessed the potential relationship between physical and psychological symptoms within their cohorts. Meta-regression analysis of 5 combinations of paired physical and psychological outcomes showed a significant moderating effect of symptoms of depression (Beck Depression Index) on mobility (Timed Up and Go Test) (Coefficient=0.3675, 95% CI 0.0901 to 0.6450, p=0.0123) and balance (Berg Balance Score) scores (Coefficient=-1.2518, 95% CI -1.7687 to -0.7349, p=0.0002).

Conclusions: Although both physical and psychological outcomes were used in the studies analyzed in this review, the relationship between physical and psychological symptoms was not examined. Meta-regression of available data suggests that as the performance on measures of physical function decreases the symptoms of depression increase. Analysis suggests that this relationship may be moderated by psychological presentation however requires further investigation.

Implications: Clinicians and researchers should be aware of both the physical and psychological symptoms of PD and consider the potential for these to be inter-related. Further work is required to formally assess the relationship between the physical and psychological symptoms of PD and monitor this over time.

Funding acknowledgements: Work completed part of PhD programme at YSJ University. No funding acknowledgements to declare.

Keywords:
Parkinson’s Disease
Psycho-physical Relationship
Mental Health

Topics:
Mental health
Neurology: Parkinson's disease

Did this work require ethics approval? Yes

Institution: York St John University

Committee: School of Science, Technology, and Health Research Ethics Committee

Ethics number: STHEC0045