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Table 3 Linear regression analysis with presence of sleep disturbance as independent variable and COPD severity at 2-year follow-up as dependent variable

From: Longitudinal associations between sleep disturbance and disease severity in patients with COPD

 Dependent VariableDependent Variable
Independent variable2 yr FEV1% pp2 yr mMRC2 yr SGRQ2 yr ISWT distance2 yr RV pp2 yr DLCO pp
β95% CIp-valueβ95% CIp-valueβ95% CIp-valueβ95% CIp-valueβ95% CIp-valueβ95% CIp-value
Model 1:
 Baseline SD−0.02(−6.86, 5.04)0.760.12(− 0.09, 0.62)0.140.18(0.84, 11.66)0.02−0.06(−66.22, 34.68)0.540.08(−6.17, 17.95)0.34−0.16(− 12.22, 0.03)0.05
Model 2:
 Baseline SD0.03(−1.42, 3.73)0.380.11(−0.05, 0.55)0.100.01(−2.68, 3.51)0.79−0.02(−31.63, 23.28)0.760.03(− 5.08, 9.62)0.54−0.06(−5.32, 0.37)0.09
 Baseline DV0.91(0.86, 0.99)< 0.0010.57(0.49, 0.80)< 0.0010.85(0.77, 0.94)< 0.0010.80(0.68, 0.91)< 0.0010.79(0.72, 0.94)< 0.0010.89(0.80, 0.95)< 0.001
 Age−0.03(− 0.28, 0.16)0.46− 0.06(− 0.03, 0.01)0.34− 0.03(− 0.32, 0.15)0.47−0.13(−5.20, − 0.69)0.01−0.01(− 0.63, 0.52)0.85− 0.05(− 0.36, 0.08)0.20
 Sex0.01(−2.27, 2.86)0.820.02(−0.26, 0.35)0.770.00(−2.90, 3.14)0.94−0.02(− 35.08, 24.40)0.72− 0.03(−10.16, 4.96)0.50− 0.05(−4.95, 0.71)0.14
 Race−0.07(−13.89, − 0.35)0.040.02(− 0.71, 0.88)0.820.02(−6.42, 9.47)0.71− 0.06(− 128.69, 30.14)0.220.01(−17.81, 20.61)0.89− 0.03(− 10.04, 4.90)0.50
 BMI− 0.00(− 0.33, 0.32)0.970.12(− 0.00, 0.07)0.080.03(− 0.24, 0.52)0.480.03(− 2.72, 4.59)0.61−0.03(− 1.23, 0.66)0.55− 0.01(− 0.42, 0.34)0.84
 Smoking status0.03(− 1.42, 3.98)0.350.07(− 0.15, 0.47)0.310.10(0.38, 6.64)0.030.04(− 17.84, 39.32)0.46−0.06(−12.24, 3.01)0.230.01(− 2.55, 3.46)0.76
  1. Note: FEV1 pp. = forced expiratory volume in 1 s percent predicted, mMRC = modified Medical Research Council scale, SGRQ = St. George’s Respiratory Questionnaire, ISWT = Incremental shuttle walk test, β = standardized regression coefficient, 95% CI = 95% confidence interval, SD = sleep disturbance, DV = dependent variable, BMI = body mass index, RV pp. = residual capacity percent predicted, DLCO pp. = diffusion capacity for carbon monoxide percent predicted