Stratum | Statement 1: “Measuring lung function had a favourable effect on my quit attempt” | Statement 2: “It is justifiable to measure lung function in heavy smokers” | Statement 3‡: “The respiratory nurse was right to confront me with COPD” | Statement 4‡: “Confrontation with my lung function helped me with my quit attempt” |
Intervention group | ** | NS | ||
Experimental group | 52 (61.2) | 72 (87.8) | 83 (97.6) | 78 (92.9) |
Control group 1 | 24 (33.3) | 74 (94.9) | NA | NA |
Control group 2 | 18 (51.4) | 31 (86.1) | NA | NA |
Sex | NS | NS | NS | NS |
Males | 61 (48.0) | 120 (93.8) | 53 (98.1) | 48 (90.6) |
Females | 33 (50.8) | 57 (83.8) | 30 (96.8) | 30 (96.8) |
Self-reported smoking status at 12-month follow-up | NS | * | NS | NS |
Smoker | 48 (46.6) | 102 (95.3) | 41 (100) | 38 (95.0) |
Non-smoker | 46 (51.7) | 75 (84.3) | 42 (95.5) | 40 (90.9) |
Educational level | NS | NS | NS | NS |
Lower 50% (level 1–3) | 43 (48.9) | 80 (87.0) | 38 (95.0) | 37 (94.9) |
Higher 50% (level 4–7) | 51 (49.0) | 97 (93.3) | 45 (100) | 41 (91.1) |
FEV1 post-bd.% pred at baseline¶ | NS | NS | NS | * |
Lower 50% (FEV1<84.1) | 54 (50.9) | 75 (86.2) | 44(95.7) | 44 (97.8) |
Higher 50% (FEV1⩾84.1) | 40 (46.5) | 102 (93.6) | 39 (100) | 34 (87.2) |
*p<0.05; **p<0.01; NS, no statistically significant difference (p⩾0.05).
†The original response scale ranged from 1 (completely disagree) to 5 (completely agree). Participants who agreed or completely agreed (scores 4 and 5) were clustered. The χ2 tests were used to test differences in proportion of subjects who agreed with the proportion of subjects who disagreed (scores 1 and 2). Subjects who gave a neutral answer (score 3) were excluded from the statistical testing (n = 13 (6.3%), n = 9 (4.4%), n = 0, n = 1 (1.1%) for the statements 1, 2, 3 and 4 respectively).
‡Questions 3 and 4 refer to the experimental group only.
¶Baseline post-bronchodilator forced expiratory volume in 1 s (percentage of predicted value).
COPD, chronic obstructive pulmonary disease; NA, not applicable; RN, respiratory nurse.