Table 2

Effect of treatment (ABC tool) on the total score and subdomains of the SGRQ at different points in time, as established with mixed linear regression correcting for age, gender, healthcare setting and smoking status, n=334

 Observed score, mean (SD)β*95% CIp Value
Intervention groupControl groupLowerUpper
SGRQ symptoms
 6 months48.81 (22.83)43.15 (26.19)−0.83−3.952.300.602
 12 months44.65 (21.58)45.63 (26.27)−5.50−8.92−2.070.002
 18 months46.16 (23.69)45.33 (26.46)−4.52−8.15−0.890.015
SGRQ activity
 6 months45.35 (24.54)43.36 (25.96)−0.86−3.742.020.557
 12 months44.66 (24.92)43.62 (26.86)−1.12−4.001.770.447
 18 months44.23 (26.59)43.72 (27.45)−2.34−5.520.830.147
SGRQ impact
 6 months25.45 (16.24)23.14 (15.92)0.23−1.822.290.822
 12 months24.43 (15.94)24.51 (15.59)−1.46−3.420.500.144
 18 months23.86 (15.58)24.68 (17.36)−2.59−4.66−0.520.014
SGRQ total score
 6 months39.88 (19.09)36.79 (20.29)−0.90−2.851.050.365
 12 months37.91 (18.33)38.10 (20.80)−2.96−4.99−0.930.004
 18 months38.39 (19.26)37.84 (21.92)−3.08−5.36−0.800.008
  • *β=mixed linear regression weight for treatment at that point in time. β<0 indicates a lower score in the intervention group. Lower scores or negative change scores indicate a higher quality of life based on the SGRQ. Effects in this table are based on the mixed model after deleting the treatment effect at baseline, which was never significant. Effects before deleting the treatment effect were very similar and agreed with the present table in terms of significance yes/no.

  • ABC tool, Assessment of Burden of COPD tool; SGRQ, St. George's Respiratory Questionnaire.