Table 6

Hierarchic multiple regression analysis of demographic, medical, and psychological variables in relation to PSQI

Model 1

Model 2

Model 3

Model 4





B

P value

B

P value

B

P value

B

P value


Age (years)

0.057

0.122

0.064

0.081

0.032

0.314

0.055

0.103

Gender (male)

0.738

0.108

0.098

0.823

-0.228

0.575

-0.435

0.292

Years of education

-0.583

0.011

-0.333

0.105

-0.266

0.181

-0.190

0.318

Student (yes)

-1.261

0.083

0.587

0.365

-0.805

0.203

-0.455

0.449

Employment (yes)

-1.068

0.078

-1.099

0.043

-0.638

0.225

-0.798

0.112

Married (yes)

0.174

0.788

0.168

0.769

0.010

0.985

0.011

0.984


ESR

0.007

0.535

0.009

0.399

CRP

-0.005

0.941

-0.022

0.706

Disease duration

-0.055

0.230

-0.052

0.214

Morning stiffness (minute)

0.001

0.919

0.001

0.904

Fingertip-to-floor distance (cm)

-0.011

0.481

-0.009

0.531

Overall assessment of health (VAS)

0.029

0.760

-0.039

0.658

Nocturnal pain (VAS)

0.267

0.012

0.258

0.009

Total back pain (VAS)

0.133

0.302

0.168

0.159

BASMI

-0.222

0.100

-0.149

0.233

BASDAI (VAS)

0.456

0.005

0.210

0.168

BASFI (VAS)

-0.067

0.595

-0.157

0.184


SDS

0.064

0.004

0.059

0.008

SAS

0.170

0.000

0.120

0.000


R2 (%)

8.5

32.0

32.4

42.6

Adjusted R2 (%)

6.7

28.0

30.6

38.9


Model 1 F = 4.756; P = 0.000; Model 2 F = 8.176; P = 0.000; Model 3 F = 18.290; P = 0.000; Model 4 F = 11.507; P = 0.000. BASDAI, Bath Ankylosing Spondylitis Disease Activity Index; BASFI, Bath Ankylosing Spondylitis Functional Index; BASMI, Bath Ankylosing Spondylitis Metrology Index; CRP, C-reactive protein; ESR, erythrocyte sedimentation rate; PSQI, Pittsburgh Sleep Quality Index; SAS, Self-rating Anxiety Scale; SDS, Self-rating Depression Scale; VAS, visual analogue scale.

Li et al. Arthritis Research & Therapy 2012 14:R215   doi:10.1186/ar4054

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