Table 2.

Summary of the hierarchical linear regression models

Outcome	Model 1	Model 2	Model 3	Model 4	Model 5	Model 6	Model 7
Pain intensity
R2	0.312	0.362	0.405	0.489	0.496	0.514	0.531
ΔR2	--	0.046	0.043	0.085	0.007	0.018	0.017
Pain interference
R2	0.330	0.343	0.374	0.498	0.512	0.520	0.540
ΔR2	--	0.013	0.031	0.124	0.013	0.008	0.020
Pain intensity*
R2	0.245	0.288	0.348	0.463	0.471	0.493	0.510
ΔR2	--	0.042	0.060	0.116	0.008	0.022	0.017
Pain interference*
R2	0.254	0.264	0.307	0.479	0.500	0.509	0.524
ΔR2	--	0.010	0.043	0.172	0.018	0.012	0.015

Model 1: Disease-related factors; Model 2: Model 1 + demographic factors; Model 3: Model 2 + socioeconomic factors; Model 4: Model 3 + physical factors; Model 5: Model 4 + psychological factors; Model 6: Model 5 + behavioral factors; Model 7: Model 6 + social factors.

^*These models comprise the sensitivity analyses that include the modified Systemic Lupus Activity Questionnaire (SLAQ) which removes overt mentions of pain including stomach pain, chest pain, headache, joint swelling, joint pain, muscle pain