Table 2: Correlations expressed as Spearman’s rank correlation coefficient between quality of life measure and selected variables of interest.

PDQ-8
AllESAS
Rho valueRho valueRho value

Age0.0780.4420.1010.497−0.0560.688
Disease duration 0.011−0.0650.6630.2460.076
LEDD0.1610.109−0.1770.2340.0760.589
Hoehn and Yahr score <0.001
NMSQuest <0.001 <0.001 <0.001
NMSS total <0.001 0.002 <0.001

NMSS domain
 Cardiovascular 0.0090.1440.334 0.036
 Sleep/fatigue <0.001 0.023 0.001
 Mood/apathy <0.001 <0.001 0.011
 Perceptual problems 0.0220.1470.3240.1910.172
 Attention/memory <0.001 <0.001 0.006
 Gastrointestinal 0.0080.2480.0920.2560.064
 Urinary0.1360.176−0.1240.4070.2020.146
 Sexual function0.1460.1470.0890.5540.2680.053
 Miscellaneous 0.0110.2640.0730.1480.291

Abbreviations: AS: advanced-stage Parkinson’s disease; ES: early-stage Parkinson’s disease; LEDD: levodopa equivalent daily dose.
For explanation, see Section 2.2.
The strength of the association for correlation coefficients is interpreted as follows: *0.20 to 0.39, weak; **0.40 to 0.59, moderate; ***0.60 to 0.79, strong; significant values are bold.