Background: Controlled-release levodopa-carbidopa (CRLC) improves some aspects of Parkinson's disease (PD) in patients previously treated with standard levodopa formulations (SL). However, little is known about the effect of this strategy on the health-related quality of life (QoL).
Objective: To assess the QoL and clinical changes due to the conversion of treatment from SL to CRLC in patients with mild to moderate PD.
Patients and methods: Through the Nottingham Health Profile (NHP), QoL was measured in 276 non-selected PD patients included in a multicenter, open study. Guidelines for switching to CRLC and optimization of treatment were given. Assessment of patients was carried out by means of the Hoehn & Yahr, UPDRS, and Schwab & England scales, and questionnaires for dyskinesias and sleep. Examination of the NHP-Spanish Version-scaling properties by fitting data to the Rasch model, disclosed that 3 NHP scales (Emotional reactions, Pain, and Physical mobility) and the NHP distress index (NHPD) were suitable for efficacy analysis.
Results: Comparison of scores at baseline and at the end of the study showed significant improvement (paired Student t-test, p < 0.0001) in all these four scales associated with the change to CRLC. Responsiveness to change of the NHP was high. In the present study, changes in QoL were not contingent to baseline factors such as age, gender, stage of disease or ADL capabilities.
Conclusion: Conversion to CRLC significantly improves the QoL of patients with mild to moderate PD.