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. 2018 Aug 29;18:89. doi: 10.1186/s12874-018-0548-0

Table 4.

Correlations among variables in full simulated memory cognitive score data and differences compared to correlations among variables in available case analyses data, data imputed using multiple imputation and after applying pattern mixture modelling

Memory cognitive function Smoking status Age Grade Education
Phase 5 7 9 5 7 9 5 5 5
Full simulated data Mem 5 1
Mem 7 0.4419 1
Mem 9 0.4423 0.4458 1
Smoke 5 −0.0806 −0.0884 −0.1041 1
Smoke 7 − 0.0715 − 0.0800 − 0.0948 0.9616 1
Smoke 9 −0.0636 −0.0764 − 0.0902 0.9337 0.9592 1
Age −0.2729 − 0.3127 − 0.3379 0.0281 0.0369 0.0451 1
Grade −0.2404 − 0.1913 − 0.1660 0.0983 0.0881 0.0817 −0.0501 1
Education 0.2058 0.1919 0.1779 −0.1114 − 0.1043 − 0.1005 − 0.0784 − 0.3691 1
Differencesa in correlations from those above
Available case Mem 5 0
Mem 7 0.0355 0
Mem 9 0.0544 0.0630 0
Smoke 5 0.0159 0.0029 0.0040 0
Smoke 7 0.0071 0.0032 0.0004 0.0009 0
Smoke 9 0.0137 −0.0005 0.0050 0.0025 0.0087 0
Age −0.1632 − 0.1679 − 0.2154 − 0.0253 − 0.0237 − 0.0194 0
Grade −0.0120 − 0.0102 − 0.0125 0.0066 0.0043 0.0004 −0.0104 0
Education 0.0052 0.0032 0.0339 −0.0050 − 0.0022 0.0015 − 0.0151 − 0.0031 0
Multiple imputation Mem 5 0
Mem 7 0.0157 0
Mem 9 0.0970 0.0364 0
Smoke 5 0.0528 0.0579 0.0306 0
Smoke 7 0.0522 0.0550 0.0360 0.0062 0
Smoke 9 0.0532 0.0506 0.0377 0.0083 0.0080 0
Age −0.0186 −0.0298 − 0.0269 − 0.1200 − 0.1246 − 0.1237 0
Grade 0.0067 − 0.0012 − 0.0070 − 0.0116 − 0.0145 − 0.0079 0 0
Education − 0.0067 0.0169 0.0066 0.0282 0.0272 0.0329 0 0 0
Pattern mixture modelling Mem 5 0
Mem 7 0.0115 0
Mem 9 0.0877 0.0099 0
Smoke 5 0.0528 0.0675 0.0410 0
Smoke 7 0.0522 0.0655 0.0464 0.0062 0
Smoke 9 0.0532 0.0612 0.0481 0.0083 0.0080 0
Age −0.0186 − 0.0204 − 0.0194 − 0.1200 − 0.1246 − 0.1237 0
Grade 0.0067 0.0020 0.0007 −0.0116 − 0.0145 − 0.0079 0 0
Education −0.0067 0.0123 −0.0001 0.0282 0.0272 0.0329 0 0 0

aDifferences in correlations are calculated as correlation in analysis type minus correlation in full simulated data