Table 5—

Adjusted associations between unreported and reported exacerbations and the 1-yr change in St George's Respiratory Questionnaire (SGRQ) score among patients completing the study#

ExacerbationsPatients nSGRQ domain β (95% CI)
TotalActivityImpactSymptom
None1670 (ref)0 (ref)0 (ref)0 (ref)
Unreported only
 1301.22 (-4.05–6.48)3.40 (-2.54–9.34)1.30 (-5.16–7.76)-3.38 (-9.65–2.88)
 >1454.61 (0.09–9.13)6.36 (1.28–11.44)3.17 (-2.37–8.71)3.62 (-1.76–8.99)
Reported only
 1705.13 (1.15–9.11)3.99 (-0.50–8.48)3.37 (-1.50–8.24)11.73 (7.01–16.45)
 >14612.33 (7.72–16.95)10.78 (5.57–16.00)11.33 (5.67–16.99)17.28 (11.80–22.77)
Mixed+928.22 (4.46–11.98)9.34 (5.11–13.57)5.53 (0.92–10.14)13.99 (9.51–18.46)
  • The estimated β represents the mean change in SGRQ score at 1 yr for patients with exacerbations compared with patients with no exacerbation. For instance, 4.61 means that the mean change in SGRQ total score at 1 yr is 4.61 points worse for patients with more than one unreported exacerbation than in those with no exacerbation. Other significant (p<0.05) estimates (adjusted β (95% CI)) in multivariate models are as follows. 1) In the model for the SGRQ total score: anxiety (hospital anxiety and depression scale (HADS) anxiety score of ≥8 versus <8) (5.23 (0.05–10.42)); every 10-unit increase in self-efficacy score (0.74 (0.10–1.37)); current smoking (3.66 (0.28–7.04)); 50-m increase in 6-min walking distance (6MWD) (-0.70 (-1.32– -0.08)); every 1-grade increase in UK Medical Research Council (MRC) dyspnoea scale (1.63 (0.23–3.03)); and baseline SGRQ total score (-0.52 (-0.62– -0.42)). 2) In the model for the SGRQ activity score: depression (HADS depression score of ≥8 versus <8) (4.69 (0.52–8.86)); self-efficacy (0.73 (0.01–1.45)); every 10% increase in percentage predicted forced expiratory volume in 1 s (FEV1) (-1.43 (-2.38– -0.47)); current smoking (4.29 (0.46–8.12)); every 50-m increase in 6MWD (-0.87 (-1.56– -0.18)); dyspnoea (1.66 (0.05–3.28)); and baseline SGRQ activity score (-0.59 (-0.68– -0.50)). 3) In the model for the SGRQ impact score: anxiety (7.08 (0.67–13.49)); self-efficacy (1.10 (0.32–1.87)); dyspnoea (1.97 (0.30–3.64)); and baseline SGRQ impact score (-0.54 (-0.64– -0.44)). 4) In the model for the SGRQ symptom score: every 1-yr increase in age (-0.19 (-0.38– -0.01)); depression (4.64 (0.25–9.03)); dyspnoea (1.59 (0.01–1.38)); daily productive cough (4.26 (0.66–7.86)); and baseline SGRQ symptom score (-0.63 (-0.73– -0.53)). ref: reference. #: n = 450; : adjusted for baseline SGRQ score, age, sex, marital status, current employment, education, current smoking, percentage predicted FEV1, MRC dyspnoea grade, 6MWD, daily productive cough, daily wheezing, depression, anxiety, self-efficacy, social support, use of long-acting bronchodilators and inhaled corticosteroids, long-term oxygen therapy, significant comorbid conditions, and the occurrence of at least one exacerbation (regardless of reporting status) during the last 3 months of follow-up; +: unreported (≥1) and reported (≥1).