Comparison of patient rated treatment response with measured improvement in Parkinson's disease
- Correspondence to Dr D J M McGhee, Division of Applied Health Sciences, University of Aberdeen, Polwarth Building, Foresterhill, Aberdeen AB25 2ZD, UK;
Contributors MBD undertook the statistical analysis and interpretation of the data, and drafted and revised the manuscript. DJMM undertook the statistical analysis and interpretation of the data, and drafted and revised the manuscript. He was also involved in acquisition of the data through the ongoing Parkinsonism Incidence in North-East Scotland (PINE) study. CEC devised the PINE study, and produced the idea for this manuscript. He revised the manuscript and provided overall supervision for this work. He obtained funding for the PINE study and was involved in acquisition of the data.
- Received 13 March 2012
- Revised 19 April 2012
- Accepted 24 April 2012
- Published Online First 24 May 2012
Background A marked response to dopamine replacement therapy is important in supporting a diagnosis of idiopathic Parkinson's disease (PD). The aim of the study was to compare PD patients' subjective rating of improvement with measured improvement on a number of scales.
Methods People with clinically defined PD were identified from a prospective long term follow-up study of incident parkinsonian patients. Changes in the Unified Parkinson's Disease Rating Scale (UPDRS) (activities of daily living and motor subsections), timed tests and Parkinson's Disease Questionnaire, full version, between assessments immediately before starting adequate dopamine replacement and the two subsequent follow-up assessments (mean 6 and 12 months after baseline) were calculated. These were compared with the patients' own subjective ratings of improvement (nil, slight, moderate, good, excellent).
Results 133 patients were included (mean age 71 years, 56% men). Thirty-eight patients were treated with a dopamine agonist and 95 with l-dopa (median l-dopa equivalent dose 300 mg). Most patients showed improvements in their measured scores but there was no statistically significant association between these scores and the patient subjective response, except for the motor UPDRS at the first follow-up. A third of those who showed no improvement in their motor UPDRS at the first follow-up rated their improvement as moderate or better, while 29% of those whose motor UPDRS improved by over 50% said they had no or slight improvement.
Conclusion PD patients' subjective ratings of their degree of improvement often do not accurately reflect the degree of objective change in parkinsonian impairment or disability. Clinicians should record a simple measure of motor impairment before and after treatment to assess treatment response more accurately.
MBD and DJMM are joint first authors and contributed equally to the manuscript.
Funding The PINE study was funded by Parkinson's UK (grant Nos G-0502, G-0914), the BMA Doris Hillier Award, NHS Grampian Endowments, SPRING (Special Parkinson's Research Interest Group) and the RS MacDonald Trust. DJMM is supported by a grant from the National Institute for Health Research (NIHR) (grant No RP-PG-0707-10124).
Competing interests None.
Ethics approval Ethics approval was provided by North of Scotland Research Ethics Committee.
Provenance and peer review Not commissioned; externally peer reviewed.
Data sharing statement The authors are open to discussion with interested parties regarding using data from the ongoing PINE study.