Effects of psychosocial factors on monitoring treatment effect in newly diagnosed rheumatoid arthritis patients over time: response data from the tREACH study

Figures & data

Table 1. Baseline characteristics.

Characteristics	All patients (n = 281)	Completers (outcome DAS available at 3, 9, and 15 months) (n = 161)	Non-completers (outcome DAS missing at 3, 9, or 15 months) (n = 120)	p*
Demographic
Age (years)	53 (14)	53 (14)	53 (14)	0.981
Gender (female)	190 (68)	104 (65)	86 (72)	0.210
Disease-related
Duration of complaints (days)	166 ± 91	168 ± 87	164 ± 97	0.662
RF-positive	228 (81)	138 (86)	90 (75)	0.023
ACPA-positive	226 (80)	133 (83)	93 (78)	0.286
Fulfilling ACR/EULAR 1987 criteria	189 (67)	118 (73)	71 (59)	0.013
Fulfilling ACR/EULAR 2010 criteria	267 (95)	154 (96)	113 (94)	0.571
DAS	3.36 ± 0.96	3.39 ± 0.97	3.33 ± 0.95	0.648
HAQ	1.00 ± 0.66	0.97 ± 0.65	1.03 ± 0.67	0.496
tSvHs	0 (0–0)	0 (0–0)	0 (0–0)	0.266†
Anxiety (HADS)	5.8 ± 3.7	5.8 ± 3.9	5.8 ± 3.5	0.861
Depression (HADS)	4.6 ± 3.4	4.5 ± 3.4	4.6 ± 3.4	0.843
Fatigue (FAS)	22.2 ± 7.0	22.6 ± 7.3	22.0 ± 6.8	0.542
Coping with pain (CORS)	15.5 ± 5.2	16.2 ± 5.2	15.0 ± 5.1	0.058

Data are shown as n (%), mean ± sd, or median (interquartile range).

*Differences between completers and non-completers were tested. Student’s t-test and Pearson’s chi-squared test were used as appropriate, unless specified otherwise.

†Wilcoxon rank-sum test.

RF, rheumatoid factor; ACPA, anti-citrullinated protein antibodies; ACR, American College of Rheumatology; EULAR, European League Against Rheumatism; DAS, Disease Activity Score; HAQ, Health Assessment Questionnaire; tSvHs, total Sharp van der Heijde score; HADS, Hospital Anxiety and Depression Scale; FAS, Fatigue Assessment Scale; CORS, Coping with Rheumatic Stressors.

Table 2. Multivariable linear regression analysis of psychosocial factors at baseline and 6 and 12 months on Disease Activity Score (DAS) at 3, 9, and 15 months, respectively.

	Multivariable, per factor			Multivariable, full			Multivariable, after backward elimination
	Beta	p	95% CI	Beta	p	95% CI	Beta	p	95% CI	%*
DAS 3 months (n = 265)
Anxiety (T0)	0.043	0.005	0.013 to 0.073	0.037	0.050	−0.000 to 0.075	0.037	0.015	0.007 to 0.067	65.3
Depression (T0)	0.034	0.037	0.002 to 0.066	−0.001	0.963	−0.044 to 0.042				11.4
Fatigue (T0)	0.015	0.070	−0.001 to 0.031	0.001	0.935	−0.189 to 0.020				7.8
Coping with pain (T0)	0.028	0.012	0.006 to 0.051	0.024	0.051	−0.000 to 0.048	0.024	0.036	0.002 to 0.046	56.7
DAS 9 months (n = 251)
Anxiety (T6)	0.017	0.217	−0.010 to 0.044	0.004	0.822	−0.034 to 0.043				12.3
Depression (T6)	0.023	0.115	−0.006 to 0.052	0.001	0.975	−0.046 to 0.048				12.6
Fatigue (T6)	0.014	0.060	−0.001 to 0.028	0.006	0.602	−0.015 to 0.026				20.4
Coping with pain (T6)	0.025	0.016	0.005 to 0.045	0.021	0.081	−0.003 to 0.044	0.025	0.016	0.005 to 0.045	59.2
DAS 15 months (n = 162)
Anxiety (T12)	0.012	0.459	−0.020 to 0.043	−0.013	0.525	−0.055 to 0.028				11.6
Depression (T12)	0.028	0.095	−0.005 to 0.060	0.011	0.669	−0.040 to 0.062				18.2
Fatigue (T12)	0.019	0.020	0.003 to 0.035	0.017	0.179	−0.008 to 0.041	0.019	0.020	0.003 to 0.035	51.5
Coping with pain (T12)	0.019	0.102	−0.004 to 0.041	0.007	0.619	−0.019 to 0.033				13.4

All analyses are corrected for age, gender, rheumatoid factor, anti-citrullinated protein antibodies, initial treatment group, medication change at the previous visit, and DAS at the previous visit.

*Selection rate of psychosocial factors after applying backward elimination in bootstrap samples.

The figures in bold type indicate a significant association for the covariate with the outcome.

Table 3. Association of psychosocial factors at baseline and 6 and 12 months on Disease Activity Score (DAS) components at 3, 9, and 15 months, respectively, by zero-inflated negative binomial regression or linear regression.

	SJC44*		ln ESR†		RAI*		GH†
	Beta	p	Beta	p	Beta	p	Beta	p
DAS 3 months (n = 252)
Anxiety (T0)	0.006	0.723	−0.005	0.752	0.033	0.031	1.728	< 0.001
Depression (T0)	−0.002	0.895	0.016	0.353	0.008	0.631	1.687	< 0.001
Fatigue (T0)	0.014	0.129	−0.004	0.648	0.008	0.361	0.726	0.001
Coping with pain (T0)	0.046	< 0.001	0.030	0.008	0.021	0.055	0.121	0.677
DAS 9 months (n = 214)
Anxiety (T6)	0.004	0.859	−0.014	0.469	0.012	0.508	1.689	< 0.001
Depression (T6)	−0.020	0.371	−0.024	0.226	0.026	0.159	2.199	< 0.001
Fatigue (T6)	−0.002	0.821	−0.024	0.011	0.025	0.003	1.045	< 0.001
Coping with pain (T6)	−0.015	0.379	−0.015	0.275	0.029	0.025	0.900	0.008
DAS 15 months (n = 141)
Anxiety (T12)	0.008	0.817	−0.010	0.636	0.020	0.458	0.499	0.334
Depression (T12)	−0.041	0.247	0.013	0.547	0.041	0.078	0.717	0.172
Fatigue (T12)	0.001	0.952	−0.008	0.494	0.039	0.002	0.478	0.083
Coping with pain (T12)	0.017	0.462	−0.011	0.514	0.063	< 0.001	−0.158	0.686

All analyses are corrected for age, gender, rheumatoid factor, anti-citrullinated protein antibodies, initial treatment group, medication change at the previous visit, and DAS at the previous visit.

*Zero-inflated negative binomial regression.

†Linear regression.

SJC44, 44-joint swollen joint count; ln, natural logarithm; ESR, erythrocyte sedimentation rate; RAI, Ritchie Articular Index; GH, Global Health.

The figures in bold type indicate a significant association for the covariate with the outcome.