Validity and inter-rater reliability of the Lindop Parkinson's Disease Mobility Assessment: a preliminary study

Abstract Objectives To assess the validity and inter-rater reliability of the Lindop Parkinson's Disease Mobility Assessment (LPA); a scale developed to gather objective information on gait and bed mobility in patients with Parkinson's disease. Design Two therapists scored a group of patients with Parkinson's disease using the motor examination section of the Unified Parkinson's Disease Rating Scale (UPDRS-ME) and the LPA scale. The association between scores obtained using the two scales was calculated, and the scores obtained by the therapists using each scale were compared. Setting A Parkinson's disease clinic in a day hospital in a district general hospital. Participants Forty-nine subjects with Parkinson's disease were recruited (33 males, 16 females, mean age 75.84 ± 7.16 years). Results There was a significant association between the LPA and UPDRS-ME data for both raters (Rater A, rho −0.67; Rater B, rho −0.63; P < 0.001). The limits of agreement showed that the two raters scored within two scale points of each other on 95% of occasions, and that there was no systematic bias between raters. Percentage agreement between raters ranged from 82% to 100% for the LPA. The LPA took significantly less time to complete [mean 7.7 (standard deviation 2.9) minutes] than the UPDRS-ME [mean 10.5 (standard deviation 2.2) minutes; P < 0.001]. Conclusions The results suggest that the LPA is a valid measure with good inter-rater reliability. It is quick and easy to administer, and provides objective information about the gait and bed mobility of elderly patients with Parkinson's disease.