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Table 4 Characteristics of GAMLSS models fit with smoothing splines for the median and variance, following optimization of smoothing spline knots and the power transformation of time. The best GAMLSS distribution for each metric is bolded. Results reflect within sample performance (i.e., within the development set)

From: Reference chart for knee flexion following total knee arthroplasty: a novel tool for monitoring postoperative recovery

GAMLSS Distribution

Model Degrees of Freedom

SBC

MSE

Percentage of observed values captured below model centiles

5th

25th

50th

75th

95th

NO

7.45

9298.6

166.0

6.05

23.53

47.49

73.49

97.1

GA

7.45

9364.7

165.6

6.05

22.59

45.69

73.83

98.04

TF

8.45

9303.0

171.1

6.05

24.47

48.34

73.49

97.19

BCCG

8.45

9266.5

166.4

5.12

25.15

49.87

74.51

95.14

BCT

9.45

9273.5

167.4

5.12

25.15

49.87

74.51

95.14

BCPE

9.45

9271.0

166.3

5.29

24.55

49.79

74.85

95.06

  1. Abbreviations: SBC Schwarz Bayesian Criterion, MSE Mean Squared Error, NO Normal, GA Gamma, TF t-Family, BCCG Box Cox Cole and Green, BCT Box Cox t-distribution, BCPE Box Cox Power Exponential