Agreement between relatives of Parkinson's patients and clinical observer in home diary assessments

BackgroundThe Parkinson's Disease (PD) Home Diary (HD) is a common clinical outcome measure, but studies show only fair agreement between clinical observer and patient assessments, with no significant improvement after patient training.ObjectivesTo investigate the agreement between a clinical observer and relatives of PD patients when assessing the patient's motor status in the HD. Agreement was also assessed for relative-patient and patient-observer pairs.MethodsThis observational study included 28 PD patients with motor fluctuations and their relatives. It involved a screening visit with structured training on motor fluctuations and one day of motor ratings, where the observer, relative, and patient independently assessed the patient's motor state in the HD half-hourly.ResultsObserver, patient, and relative triads completed 445 HD assessment sets. Temporal agreement was fair for observer-relatives (Cohen's κ = 0.250) and relatives-patients (κ = 0.230), but slight for patients-observer (κ = 0.120). For observer-relatives, agreement was highest for "On without dyskinesia" (71%), and lowest for "Off" (26%). Daily time distributions differed significantly between relatives and the clinical observer for "Off" (p = 0.006) and "On without dyskinesia" (p = 0.012), but not for "On with dyskinesia" (p = 1.000).ConclusionsThis study reports fair temporal agreement of motor state assessments between relatives-observer and relatives-patients, with slight agreement between patients-observer. Relatives' assessments of daily time in different motor states showed significant differences from the clinical observer assessments. This further highlights the challenges in obtaining reliable motor status data and the need for further research into objective assessment methods.