Table 4.

Baseline patient reported outcomes as predictors of follow-up HAQ score

Study details			Predictor: Baseline HAQ		Predictor: Baseline pain
Study	N	Analysis method	Associated with HAQ	Effect sizea	Associated with HAQ	Effect sizea	Adjusted for
Multivariable analyses
Malm [32]	1387	Logistic regression(HAQ cut-off = 0.75)	✓	Per unit baseline HAQ:	✓ (VAS)	Per unit baseline pain VAS:	Age, gender, disease duration
				OR 3.57 (2.84, 4.49)		OR 1.02 (1.02, 1.03)
Bansback [44]	985	Logistic regression(HAQ cut-off = 1.5)	✓	Per unit baseline HAQ:	–	–	Baseline: Carstairs deprivation index, functional grade, haemoglobin level, Larsen score; year 1: functional grade, HAQ, DAS28
				OR 1.70, p < 0.01
Combe [51]	813	Logistic regression(HAQ cut-off = 0.3)	✓	Baseline HAQ cut-off = 0.88:OR 2.90 (2.00, 4.19)	✓ (VAS)	Baseline pain VAS cut-off = 34:	Age, gender
						OR 1.69 (1.17, 2.44)
Hallert [35]	251	Generalised estimating equations analysis	–	–	✓ (VAS)	Per unit baseline pain VAS:	DMARD use, biologic use, grip force, SOFI-hand, SOFI-upper extremity, SOFI-lower extremity, GAT, pain, walking time
						b 0.01, p < 0.01
Combe [34]	191	Spearman correlation & linear regression	✓	ρ 0.47, p < 0.01	✓ (VAS)	ρ 0.32, p < 0.01	ESR, CRP, Ritchie index
				b 0.39, p < 0.01		b not reported
Bjork [49]	189	Projections to latent structure discriminant analysis (HAQ cut-off = 0.08)	✓	Baseline HAQ cut-off=0.08:	✗ (VAS)	VIP = 0.30 (“not important”)	Baseline: age, gender, grip force, SOFI-lower limb, walking speed, GAT, wellbeing, CRP, SOFI-hand, ESR, tender joints, PGA, SOFI-upper limb, swollen joints
				VIP = 1.97 (“important”)
Verstappen [36]	112	Logistic regression (HAQ cut-off = 1)	✓	Per unit baseline HAQ:	✓ (VAS)	Per unit baseline pain VAS:	Disease duration (natural log transformed)
				OR 2.63 (1.30, 5.32)		OR 1.02 (0.99, 1.03)
Eberhardt [28]	63	Logistic regression (HAQ cut-off = 1.0)	✓	Baseline HAQ cut-off = 1.00:	–	–	“[demographic,] clinical, radiographic and laboratory data”
				OR 2.08, p < 0.01
Benton [27]	42	Logistic regression (HAQ cut-off = 0.25) OR are the odds of being in the low HAQ group	✗	Per unit baseline HAQ: OR 0.16 (0.02, 1.01)	–	–	Baseline: DAS, Ritchie index, CRP, Sharp score; one year: DAS, Ritchie, CRP, HAQ
Univariable analyses
Jäntti [33]	121	Somers’ d	✓	Somers’ d = 0.28 (0.11, 0.45)	–	–	–
Contreras-Yanez [25]	107	Student’s t test Comparison groups: HAQ ≤ 0.2 at 5 years, yes/no.	✓	Median (IQR) baseline HAQ:	–	–	–
				HAQ ≤ 0.2 1.4 (0.8–2)
				HAQ > 0.2 2.1 (1.6–3) p < 0.01

See Table 2 for acronym definitions: DAS28, ESR, HAQ, N.

See Table 3 for acronym definitions: b, DMARD, GAT, OR, PGA, SOFI, VIP.

^aBrackets indicate 95% confidence interval unless otherwise stated; CRP = C-reactive protein, IQR = interquartile range, VAS = visual analogue scale, ρ = Spearman’s rho.