Table 8

Model of logistic regression

A Multinomial regression
Self reported level of careExplanatory variablesExp(B)WaldSignificance95% CI
Level 2Age1.0080.050.820.942 to 1.078
PF0.9821.850.170.956 to 1.008
P1.0131.050.310.988 to 1.039
MH0.9840.820.370.951 to 1.019
EV1.0120.280.600.968 to 1.057
GHP0.9850.800.370.952 to 1.018
DLTV subscale 10.9624.080.0440.927 to 0.999
DLTV subscale 21.0020.010.910.967 to 1.039
DLTV subscale 30.9910.160.690.950 to 1.034
DLTV subscale 41.0203.420.0640.999 to 1.041
DVA better eye1.630.310.580.29 to 9.09
Level 1Age0.8907.960.0050.821 to 0.965
PF0.94012.580.0000.909 to 0.973
P0.9990.010.9410.970 to 1.028
MH0.9603.370.0660.919 to 1.003
EV1.0624.130.041.002 to 1.125
GHP0.9920.140.7030.973 to 1.025
DLTV subscale 10.9858.400.0040.929 to 1.044
DLTV subscale 20.9622.660.100.918 to 1.008
DLTV subscale 31.0090.090.760.954 to 1.067
DLTV subscale 40.9980.010.910.973 to 1.025
DVA better eye6.652.800.090.72 to 61.1
B Binomial logistic regression (base category level 3)
Level 2DLTV subscale 11.03917.090.0001.020 to 1.058
SF 36 PF1.0173.890.0491.000 to 1.033
C Binomial logistic regression (base category level 3)
The multinomial regression model (A) was run with the three levels of care as the dependent variable and age, sex, SF36 dimensions, and DLTV subscales as explanatory variables. The model shows that the decrease in scores in DLTV subscale 1 was most strongly influenced by the transition from care level 3 to 2. The decrease in PF scores and age most strongly influenced the transition from care level 2 to level 1 with a contribution from DLTV subscale 2. To progress to a more parsimonious model variables that were counterintuitive were first removed followed by those explanatory variables whose p values exceeded 0.1. (SPSS default for stepwise backwards and also equivalent to a 5% test in one direction only.)
The binomial regression model (B) confirmed that DLTV subscale 1 was most important in the transition from care level 3 to 2 while DLTV subscale 2 was most important in the transition to care level 1 (C).
Level 1DLTV subscale 21.0419.540.0021.015 to 1.068
SF 36 PF1.0318.370.0041.010 to 1.053
Min DVA0.243.150.0760.05 to 1.16