Table 6

Marginal model and random-effects models analysing time-fixed and time varying covariates


Marginal model* GEE
Random model* likelihood integration

Estimate
SE
p value
Estimate
SE
p value



Baseline






Living alone
-0.31
0.09
0.0004
-0.66
0.18
0.0002
BMI (kg/m2)






     < 25 (ref)
0


0


     25 – 29
0.30
0.10
0.002
0.69
0.20
0.0005
     ≥ 29
0.75
0.12
< 0.0001
1.46
0.23
< 0.0001
Visual acuity






     ≤ 2/10
0.64
0.20
0.001
1.21
0.35
0.0006
     > 2/10 (ref)
0


0


Perceived health






     Bad or very bad
0.76
0.15
< 0.0001
1.43
0.28
< 0.0001

Follow-up






Hospitalised (past year)
0.26
0.05
< 0.0001
0.49
0.11
< 0.0001
Temporarily bed confined (past year)
0.39
0.07
< 0.0001
0.73
0.15
< 0.0001
Number of falls ≥ 2 (past year)
0.23
0.08
0.004
0.49
0.15
0.0013

*adjusted on time since inclusion, age at inclusion, age × time, baseline disability and death

Carrière and Bouyer BMC Medical Research Methodology 2002 2:15   doi:10.1186/1471-2288-2-15