Investigating What Aspects of Sleep Improve in Rheumatoid Arthritis Patients Treated with Abatacept

Purpose: Patients with rheumatoid arthritis (RA) perceive sleep quality as an important component of their quality of life. Sleep is multi-dimensional and the objective is to investigate what aspects of sleep improve when patients are treated with abatacept.
Methods: Two randomized, double-blind, placebo controlled trials in patients with active RA were considered in this assessment: a 6 month trial (ATTAIN trial) comparing treatment with abatacept (n=258) to placebo (n=133) on a background of DMARD therapy in patients who were anti-TNF therapy failures; and a 12 month trial (AIM trial) comparing treatment with abatacept (n=433) to placebo (n=219) on a background of methotrexate therapy. Sleep quality was assessed using the validated Medical Outcomes Study sleep questionnaire (MOS-sleep). The treatment groups were compared on the 7 derived MOS-sleep scales: awakened short of breath (SoB) or with headache, snoring, sleep adequacy, sleep disturbance, somnolence, and sleep problems Index I and II (summary measures of different types of sleep problems). In addition, sleep duration (in hours) and optimal sleep (yes vs no) based on the MOS-sleep module were compared. Items are scored 0-100 with higher scores indicating more of the attribute under consideration. Since all the attributes for the scale scores are negative, a smaller number is better except for sleep adequacy which is a positive attribute. Optimal sleep is a binary variable with 1 indicating optimal sleep, so a higher proportion on this variable is better.
Results: No pertinent differences at baseline in the various items on the MOS sleep questionnaire or on the derived MOS sleep scales and other MOS summary measures were found. Comparisons of the MOS sleep scales in the ATTAIN study are summarized in the table and indicate significant improvement in the abatacept group compared to control on sleep adequacy, sleep disturbance, somnolence and both sleep problem indices I and II. The corresponding differences for the AIM study were less significant, however sleep disturbance and sleep problems index I and II were still statistically significant. For both studies, sleep quantity was not significantly difference between treatment groups, but optimal sleep significantly improved in the abatacept vs control group for both the ATTAIN (18% vs -12%, p<0.0001) and AIM (16% vs 5%, p=0.0214) study.
Conclusions: Treatment with abatacept improves several different aspects of sleep in RA patients. In particular, sleep disturbance and sleep problems given by index II are reduced, and optimal sleep is improved.
ATTAIN Study: Comparison of abatacept to control on MOS sleep scales*

ATTAIN Study: Comparison of abatacept to control on MOS sleep scales*

MOS Sleep Scales		Abatacept			Control
	n	mean	(sd)	n	mean	(sd)	p-value
SoB or Headache	253	-3.3	(21.3)	131	-0.6	(19.4)	0.2246
Snoring	250	-0.6	(21.1)	125	0.3	(24.8)	0.7106
Adequacy	256	9.0	(26.4)	131	0.6	(25.3)	0.0028
Disturbance	257	-11.3	(22.9)	131	-2.9	(21.1)	0.0005
Somnolence	256	-10.5	(19.7)	131	-1.6	(21.9)	<0.0001
Problems Index I	256	-9.5	(17.1)	131	-1.4	(16.4)	<0.0001
Problems Index II	257	-9.8	(16.7)	131	-2.1	(15.8)	<0.0001

* a negative indicates improvement except for sleep adequacy

 G.A. Wells, None; T. Li, None; J. Kirwan, None; P. Tugwell, None.