Heterogeneous Determinants of Quality of Life in Different Phenotypes of Parkinson's Disease.
OBJECTIVE
Health-related quality of life (HRQoL) is considered a very important outcome indicator in patients with Parkinson's disease (PD). A broad list of motor and non-motor features have been shown to affect HRQoL in PD, however, there is a dearth of information about the complexity of interrelationships between determinants of HRQoL in different PD phenotypes. We aimed to find independent determinates and the best structural model for HRQoL, also to investigate the heterogeneity in HRQoL between PD patients with different phenotypes regarding onset-age, progression rate and dominant symptom.


METHODS
A broad spectrum of demographic, motor and non-motor characteristics were collected in 157 idiopathic PD patients, namely comorbidity profile, nutritional status, UPDRS (total items), psychiatric symptoms (depression, anxiety), fatigue and psychosocial functioning through physical examination, validated questionnaires and scales. Structural equation model (SEM) and multivariate regressions were applied to find determinants of Parkinson's disease summary index (PDSI) and different domains of HRQoL (PDQ-39).


RESULTS
Female sex, anxiety, depression and UPDRS-part II scores were the significant independent determinants of PDSI. A structural model consisting of global motor, global non-motor and co-morbidity indicator as three main components was able to predict 89% of the variance in HRQoL. In older-onset and slow-progression phenotypes, the motor domain showed smaller contribution on HRQoL and the majority of its effects were mediated through non-motor features. Comorbidity component was a significant determinant of HRQoL only among older-onset and non-tremor-dominant PD patients. Fatigue was not a significant indicator of non-motor component to affect HRQoL in rapid-progression PD.


CONCLUSIONS
Our findings showed outstanding heterogeneities in the pattern and determinants of HRQoL among PD phenotypes. These factors should be considered during the assessments and developing personalized interventions to improve HRQOL in PD patients with different phenotypes or prominent feature.
Division of Clinical geriatrics, Department of Neurobiology, Care Sciences, and Society (NVS), Karolinska Institutet, Stockholm, Sweden; Firoozgar Clinical Research Development Center (FCRDC), Firoozgar Hospital, Iran University of Medical Sciences, Tehran, Iran.
Seyed-Mohammad
SM
Fereshtehnejad
Medical Student Research Committee (MSRC), Faculty of Medicine, Iran University of Medical Sciences, Tehran, Iran.
Mahdiyeh
M
Shafieesabet
Medical Student Research Committee (MSRC), Faculty of Medicine, Iran University of Medical Sciences, Tehran, Iran.
Farzaneh
F
Farhadi
Medical Student Research Committee (MSRC), Faculty of Medicine, Iran University of Medical Sciences, Tehran, Iran.
Hasti
H
Hadizadeh
Medical Student Research Committee (MSRC), Faculty of Medicine, Iran University of Medical Sciences, Tehran, Iran; Mental Health Research Center, Tehran Institute of Psychiatry, School of Behavioral Sciences and Mental Health, Iran University of Medical Sciences, Tehran, Iran.
Arash
A
Rahmani
Medical Student Research Committee (MSRC), Faculty of Medicine, Iran University of Medical Sciences, Tehran, Iran.
Nader
N
Naderi
Firoozgar Clinical Research Development Center (FCRDC), Firoozgar Hospital, Iran University of Medical Sciences, Tehran, Iran.
Dena
D
Khaefpanah
Movement disorders clinic, Department of neurology, Faculty of Medicine, Iran University of Medical Sciences, Tehran, Iran.
Gholam Ali
GA
Shahidi
Division of Clinical geriatrics, Department of Neurobiology, Care Sciences, and Society (NVS), Karolinska Institutet, Stockholm, Sweden; Iranian Research Center on Aging, University of Social Welfare and Rehabilitation, Tehran, Iran.
Ahmad
A
Delbari
Division of Clinical geriatrics, Department of Neurobiology, Care Sciences, and Society (NVS), Karolinska Institutet, Stockholm, Sweden; Department of Geriatric Medicine, Karolinska University Hospital, Stockholm, Sweden.
Johan
J
Lökk
D000368:Aged; D001007:Anxiety / Q000523:psychology*; D003863:Depression / Q000523:psychology*; D005221:Fatigue / Q000523:psychology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008960:Models, Psychological; D010300:Parkinson Disease / Q000175:diagnosis / Q000523:psychology*; D010641:Phenotype; D011788:Quality of Life / Q000523:psychology*; D012720:Severity of Illness Index; D012737:Sex Factors; D011795:Surveys and Questionnaires