From: Systematic review of the evidence relating FEV1decline to giving up smoking
 |  | Never smokersb (95% CI) | Ex-smokersc (95% CI) | Quittersd (95% CI) | Continuing smokerse (95% CI) |
---|---|---|---|---|---|
Unweighted analysisf | Â | Â | Â | Â | Â |
Number of betas | Â | 80 | 66 | 64 | 85 |
Unadjusted | Mean | 27.9 (23.5-32.4) | 24.1 (19.2-29.1) | 33.4 (28.4-38.4) | 42.8 (38.5-47.2) |
 | Diff 1 | -14.9*** | -18.7*** | -9.4** | Base |
 | Diff 2 | Base | -3.8NS | +5.5NS | +14.9*** |
Adjusted for age and sex | Mean | 28.8 (25.0-32.7) | 24.6(20.3-28.8) | 33.0 (28.7-37.3) | 41.9 (38.2-45.6) |
 | Diff 1 | -13.1*** | -17.4*** | -8.9** | Base |
 | Diff 2 | Base | -4.3NS | +4.2NS | +13.1*** |
Adjusted for blockg | Â | Â | Â | Â | Â |
(fixed-effects model) | Mean | 28.7 (26.4-30.9) | 27.0 (24.5-29.5) | 30.4 (27.9-33.0) | 42.1 (40.0-44.3) |
 | Diff 1 | -13.5*** | -15.2*** | -11.7*** | Base |
 | Diff 2 | Base | -1.7NS | +1.7NS | +13.5*** |
(random-effects model) | Mean | 28.6 (24.4-32.9) | 26.6 (22.2-31.0) | 30.6 (26.2-35.1) | 42.2 (38.0-46.4) |
 | Diff 1 | -13.6*** | -15.6*** | -11.6*** | Base |
 | Diff 2 | Base | -2.1NS | +2.0NS | +13.6*** |
Weighted analysish | Â | Â | Â | Â | Â |
Number of betas | Â | 71 | 57 | 56 | 77 |
Unadjusted | Mean | 26.1 (23.9-28.3) | 29.3 (25.6-32.9) | 38.3 (33.5-43.2) | 41.8 (39.1-44.6) |
 | Diff 1 | -15.7*** | -12.6*** | -3.5NS | Base |
 | Diff 2 | Base | +3.1NS | +12.2*** | +15.7*** |
Adjusted for age and sex | Mean | 28.9 (27.0-30.9) | 27.9 (24.8-30.9) | 34.2 (30.1-38.4) | 39.5 (37.2-41.9) |
 | Diff 1 | -10.6*** | -11.6*** | -5.3* | Base |
 | Diff 2 | Base | -1.1NS | +5.3* | +10.6*** |
Adjusted for blockg | Â | Â | Â | Â | Â |
(fixed-effects model) | Mean | 29.2 (28.1-30.4) | 27.6 (25.9-29.4) | 31.6 (29.1-34.1) | 40.1 (38.6-41.5) |
 | Diff 1 | -10.8*** | -12.4*** | -8.5*** | Base |
 | Diff 2 | Base | -1.6NS | +2.4NS | +10.8*** |
(random-effects model) | Mean | 29.6 (25.6-33.5) | 28.0 (23.9-32.1) | 32.2 (27.8-36.7) | 40.8 (36.9-44.8) |
 | Diff 1 | -11.3*** | -12.8*** | -8.6*** | Base |
 | Diff 2 | Base | -1.5NS | +2.7NS | +11.3*** |