Low rates of adherence for tumor necrosis factor-α inhibitors in Crohn’s disease and rheumatoid arthritis: Results of a systematic review

Table 1 Characteristics of included studies on Crohn's disease and rheumatoid arthriti

	Number of patients	Anti-TNF treatment	Definition of adherence	Adherence
Crohn's disease
Kane et al[7]	571	Infliximab	≥ 7 infusions in first year of treatment	66%
Billioud et al[17]	108	Adalimumab	Neither delaying nor missing > 1 injection in 3 mo	55%
Kane et al[18]	274	Infliximab	No "No show" designation during study period	85%
Rheumatoid arthritis
Borah et al[19]	2537	Etanercept	Medication possession ratio ≥ 0.80	71%
	1292	Adalimumab		67%
Harley et al[20]	853	Etanercept	Medication possession ratio ≥ 0.80	68%
	141	Infliximab		81%
Li et al[21]	1359	Etanercept	Proportion of days covered ≥ 0.80	32%
	1012	Infliximab		43%

Table 2 Determinants of adherence in Crohn's disease and rheumatoid arthritis

	Studies on Crohn's disease			Studies on rheumatoid arthritis
	Kane et al[7]	Billioud et al[17]	Kane et al[18]	Borah et al[19]	Li et al[21]
Female gender	OR < 1		OR < 1; P < 0.05		OR < 1
Increasing age		OR < 1			OR > 1
Immunomodulator use	OR > 1		OR < 1		OR > 1; P < 0.051
Prior biologic use	OR < 1; P < 0.05			OR > 1; P < 0.05
Increasing duration of therapy			OR < 1; P < 0.05
Increasing disease duration		OR > 1; P < 0.05

¹Significant at P < 0.05 for age 55-64 years (OR = 1.49).