Effectiveness of cognitive behavior therapy for sleep disturbance and glycemic control in persons with type 2 diabetes mellitus: A community-based randomized controlled trial in China

Table 1 Comparison of cluster levels between the intervention and control groups at baseline, 6 mo, and 12 mo

Variable	Baseline				2 mo					6 mo				12 mo
	CBT	Control	χ2/t value	P value		CBT	Control	χ2/t value	P value	CBT	Control	χ2/t value	P value	CBT	Control	χ2/t value	P value
Cluster level (group)
Number of groups	22	22	---	---		22	22	---	---	22	22	---	---	22	22	---	---
Number of participants
10	6	10	1.62	0.45		7	11	1.58	0.45	13	14	1.348	0.51	18	20	0.77	0.38
20	10	7				9	6			7	5			4	2
30	6	5				6	5			1	3			0	0
Number of follow-up general practitioners in each community
≤ 5	6	7	0.55	0.76		6	7	0.55	0.76	6	7	0.553	0.758	6	7	0.55	0.76
6-10	15	13				15	13			15	13			15	13
10-15	1	2				1	2			1	2			1	2

CBT: Cognitive behavioral therapy.

Table 2 Comparison of baseline characteristics of the intervention and control groups at baseline, 2 mo, 6 mo, and 12 mo

Variable	Baseline				2 mo				6 mo				12 mo
	CBT	Control	χ2/t value	P value	CBT	Control	χ2/t value	P value	CBT	Control	χ2/t value	P value	CBT	Control	χ2/t value	P value
Participant number	568	574	---	---	550	559			541	549	---	---	506	527	---	---
Gender (female)
Female	370	383	0.32	0.57	362	376	0.26	0.61	356	370	0.31	0.58	335	367	1.40	0.24
Age (mean + SD)	61.58 ± 9.17	61.83 ± 8.64	-0.46	0.65	61.75 ± 9.12	62.10 ± 8.86	-0.64	0.52	62.48 ± 9.14	62.75 ± 8.71	-0.50	0.62	62.87 ± 9.25	62.74 ± 8.87	0.23	0.82
Educational level
High school and above	53	56	0.42	0.81	51	56	0.38	0.83	47	56	1.09	0.58	41	50	1.00	0.61
Junior high school	240	251			234	243			231	240			208	223
High school and above	275	267			265	260			263	253			257	254
Hypertension	287	287	0.03	0.86	276	278	0.02	0.88	270	272	0.01	0.91	252	262	0.00	0.98
Comorbidities	109	118	0.34	0.56	109	114	0.06	0.81	107	110	0.01	0.92	91	110	1.37	0.24
BMI	24.77± 4.15	25.20± 4.94	-1.60	0.11	24.99 ± 4.48	25.00 ± 4.94	-0.06	0.96	24.71 ± 4.09	25.22 ± 5.01	-1.84	0.07	24.76 ± 4.00	25.28 ± 5.02	-1.84	0.07
Drinking	55	66	0.99	0.32	55	65	0.76	0.38	54	64	0.79	0.37	46	49	0.01	0.91
Smoking	80	92	0.84	0.36	79	88	0.41	0.52	76	86	0.56	0.45	64	69	0.05	0.83
Course of the disease (yr)	5.07 ± 5.25	5.21 ± 4.91	0.56	0.64	5.20 ± 5.06	5.41 ± 5.36	-0.66	0.51	5.53 ± 5.21	5.66 ± 4.76	-0.43	0.67	6.03 ± 5.28	6.20 ± 4.68	-0.52	0.60
Medication
Oral hypoglycemic agents	491	483	1.56	0.46	476	470	1.76	0.42	472	465	1.72	0.42	448	444	5.96	0.05
Insulin	45	49			42	46			39	44			37	43
Oral hypoglycemic agents plus insulin	32	42			32	43			30	40			21	40
GAD-7 score	7.56 ± 5.20	7.58 ± 5.25	-0.04	0.97	7.47 ± 5.23	7.22 ± 5.48	0.76	0.45	7.53 ± 5.65	7.14 ± 5.93	1.10	0.27	7.14 ± 5.68	6.34 ± 5.56	2.27	0.02
PHQ-9 score	7.13 ± 5.53	6.94 ± 5.47	0.59	0.55	7.23 ± 5.36	7.00 ± 5.02	0.73	0.46	7.21 ± 5.48	6.74 ± 5.21	1.44	0.15	7.20 ± 5.45	6.10 ± 4.97	3.39	0.00

Data presented as n or the mean ± SD. CBT: Cognitive behavioral therapy; BMI: Body mass index; GAD-7: General anxiety disorder; PHQ-9: Patient health questionnaire-9.

Table 3 Baseline characteristics between the completers and non-completers

Variable	Completers	Lost to follow-up					χ2/t value	P value
		Intervention group	Control group	χ2/t value	P value	Total
Participant number	1142	62	47	——	——	109	——	——
Gender (Female)	753	35	16	5.39	0.02	51	15.88	< 0.01
Age	62.44 (9.02)	62.95 (7.74)	62.23 (8.51)	0.46	0.65	62.64 (8.05)	-0.22	0.82
Educational level
High school and above	109	12	6	1.03	0.60	18	15.9	< 0.01
Junior high school	491	32	28			60
Elementary school and below	542	18	13			31
Hypertension	574	35	25	0.11	0.74	60	0.91	0.34
Comorbidities	227	18	8	2.12	0.15	26	0.75	0.32
BMI	25.02 (4.17)	24.77 (4.53)	24.43 (4.73)	0.75	0.46	24.62 (4.83)	0.94	0.35
Drinking	121	9	17	6.9	0.009	26	16.87	< 0.001
Smoking	172	16	23	6.22	0.01	39	30.46	< 0.001
Course of the disease (yr)	6.12 (4.98)	5.22 (4.53)	6.14 (5.17)	-1.001	0.32	5.62 (4.81)	1.004	0.32
Medication
Oral hypoglycemic agents	974	43	39	4.74	0.09	82	7.89	0.019
Insulin	94	8	6			14
Oral hypoglycemic agents plus insulin	74	11	2			13
GAD-7 score	6.75 (6.64)	7.31 (4.64)	7.53 (5.94)	-0.22	0.82	7.40 (5.22)	-0.99	0.32
PHQ-9 score	6.63 (5.24)	7.81 (5.39)	6.30 (4.94)	0.78	0.44	6.74 (5.19)	-0.21	0.83
PSQI score	9.45 (2.55)	9.83 (2.73)	9.51 (2.54)	0.64	0.52	9.35 (2.63)	0.39	0.70
HbA1c value	7.36 (1.14)	7.20 (1.31)	7.39 (1.45)	-0.7	0.48	7.28 (1.36)	0.69	0.49

Data presented as n or the mean (SD). BMI: Body mass index; GAD-7: General anxiety disorder; PHQ-9: Patient health questionnaire-9; PSQI: Pittsburgh Sleep Quality Index; HbA1c: Glycosylated hemoglobin.

Table 4 Comparison of Pittsburgh Sleep Quality Index scores and glycosylated hemoglobin values between the intervention and control groups

Variable	Baseline		2 mo		6 mo		12 mo		Significance level
	CBT	UC	CBT	UC	CBT	UC	CBT	UC	Condition	Time	Interaction
PSQI score	10.07 (2.38)	10.04 (2.37)	9.35 (2.79)	9.99(2.41)	9.42 (2.75)	9.92 (2.54)	9.01 (2.67)	9.91 (2.34)	< 0.001	< 0.001	< 0.001
HbA1c value	7.44 (1.12)	7.50 (1.13)	7.46 (1.10)	7.50 (1.15)	7.27 (1.18)	7.44 (1.20)	7.22 (1.14)	7.52 (1.12)	< 0.001	0.001	< 0.001

Data presented as the mean (SD). PSQI: Pittsburgh Sleep Quality Index; HbA1c: Glycosylated hemoglobin; CBT: Cognitive behavioral therapy.

Table 5 Results of intention-to-treat analysis for primary and secondary outcomes

Variable	Baseline		2 mo		6 mo		12 mo		Significance level
	CBT	Control	CBT	Control	CBT	Control	CBT	Control	Condition	Time	Interaction
PSQI score	10.07 (2.38)	10.04 (2.37)	9.36 (2.77)	9.92 (2.44)	9.45(2.75)	9.95 (2.59)	9.07 (2.69)	9.94 (2.40)	< 0.001	< 0.001	< 0.001
HbA1c value	7.44 (1.12)	7.50 (1.11)	7.46 (1.10)	7.49 (1.15)	7.27 (1.18)	7.44 (1.20)	7.23 (1.17)	7.61 (1.16)	< 0.001	0.028	< 0.001

Data presented as the mean (SD). PSQI: Pittsburgh Sleep Quality Index; HbA1c: Glycosylated hemoglobin; CBT: Cognitive behavioral therapy.