Studying the association between longitudinal mammographic density measurements and breast cancer risk: a joint modelling approach

Table 2 Parameter estimates and 95% credibility intervals for the event process under the joint modeling analysis with different association structures

	Coefficient	2.5%	97.5%	Exp(Coeff.)*	P
Model (1)
BMI (\(\gamma _1\))	0.034	0.009	0.055	1.034	0.003
MHT\(_1\) (\(\gamma _2\))	− 0.078	− 0.306	0.156	0.925	0.507
MHT\(_2\) (\(\gamma _3\))	0.400	0.016	0.728	1.492	0.039
FH\(_1\) (\(\gamma _4\))	0.518	0.280	0.717	1.678	0.000
FH\(_2\) (\(\gamma _5\))	0.060	− 0.476	0.571	1.062	0.790
Current value (\(\alpha\))	0.130	0.081	0.174	1.139	0.000
Model (2)
BMI (\(\gamma _1\))	0.034	0.008	0.057	1.035	0.007
MHT\(_1\) (\(\gamma _2\))	− 0.087	− 0.322	0.153	0.917	0.509
MHT\(_2\) (\(\gamma _3\))	0.400	0.020	0.730	1.492	0.037
FH\(_1\) (\(\gamma _4\))	0.514	0.305	0.718	1.672	0.000
FH\(_2\) (\(\gamma _5\))	0.058	− 0.487	0.538	1.060	0.777
Current value (\(\alpha _1\))	0.120	0.071	0.168	1.127	0.000
Current slope (\(\alpha _2\))	− 1.160	− 2.003	− 0.334	0.313	0.005
Model (3)
BMI (\(\gamma _1\))	0.039	0.019	0.060	1.040	0.000
MHT\(_1\) (\(\gamma _2\))	− 0.067	− 0.296	0.170	0.964	0.612
MHT\(_2\) (\(\gamma _3\))	0.404	0.019	0.725	1.498	0.036
FH\(_1\) (\(\gamma _4\))	0.511	0.301	0.720	1.667	0.000
FH\(_2\) (\(\gamma _5\))	0.064	− 0.506	0.572	1.066	0.788
Cumulative value \((\alpha\))	0.008	0.005	0.011	1.008	0.000

BMI: body mass index; MHT: menopausal hormone treatment (MHT₁=former use, MHT₂=current use); FH: family history (FH₁=yes, FH₂=missing); *: represents multiplicative change in risk per 1-unit increase in the parameter value

ISSN: 1465-542X