Source ID | Mean age of sample (years, SD) | Duration | Sample size | Mean absolute unit decline/year (SD) | Overall relative decline (%) | Variables reported to alter the rate of change | |||
Male | Female | Male | Female | Male | Female | ||||
FEV1 (mL) | |||||||||
Ahmadi, 201420 | 58.5* (9.2) | 13 | 3621 | 4441 | −17.7 (78.6) | Smoking; CRP categories | |||
Bartholomew, 199821 | 41.6 (16.1) | 6 | 445 | 1054 | −43.5 (100.4) | −30.5 (144.8) | 1.1 | 1.2 | Smoking; increased BMI |
Burchfiel, 199522 | 54.6† | 6 | 1248 | −21.6‡ | 0.7 | Smoking status | |||
Burrows, 198623 | 48.3 (19.1) | 9.6 | 158 | 308 | −10.3‡ (6.3) | −9.1‡ (5.7) | - | ||
Griffith, 200124 | 73.0* (5.3) | 7 | 1976* | 2604* | −52.3 (3.1)§ | −47.0 (2.8)§ | 1.9 | 1.7 | Caucasian versus African-American (only two measurements), smoking |
Lange, 199825 | 51.7† | 15 | 1592 | 2713 | −23.5 (10.4) | −18.3 (10.0) | 0.8 | 0.8 | Asthmatics versus non-asthmatic, smoker versus non-smoker |
Liao, 201526 | 47.4* (10.6) | 17 | 207¶ | 336¶ | −25.8 (14.0)* | Smoking, height, less versus more likely dust exposure | |||
Luoto, 201835 | 70.6* (10.6) | 13 | 171¶ | 216¶ | −46.4‡ (47.7) | 2.2‡ | Smoking, female sex (relative), male sex (absolute), elevated CRP (relative), BMI (absolute) | ||
Pearson, 199828 | 42.4 | 11.5/5.7 | 91 | 82 | −43.5 | −35.1 | 1.0 | 1.3 | - |
Sherman, 199231 | 47.9 (12.4) | 12 | 475 | 1011 | −32.8 (29.5) | −27.5 (20.4) | 1.0 | 1.1 | Smoking |
Triebner, 201732 | 36.2** | 19.7** | 648 | −22.4 (36.4) | Menopausal status, BMI | ||||
Wang, 200433 | 37** (19–65) | 5 | 71 | −56.0 (45.0) | 1.3 | ||||
Xu, 199534†† | 42.4† (11.9) | 24 | 1418 | 4875 | −28.3 (138.5) | −16.0 (135.5) | 0.7 | 0.5 | |
FVC (mL) | |||||||||
Ahmadi, 201420 | 58.5* (9.2) | 13 | 3621 | 4441 | −31.1 (118.1) | Smoking; CRP categories | |||
Bartholomew, 199821 | 41.6 (16.1) | 6 | 445 | 1054 | −47.2 (104.0) | −36.0 (154.5) | 1.0 | 1.1 | Smoking |
Griffith, 200124 | 73.0* (5.3) | 7 | 1976* | 2604* | −78.4§ (4.2) | −65.6§ (3.8) | 2.9 | 2.4 | Caucasian versus African-American (only two measurements), smoking |
Luoto, 201835 | 70.6* (10.6) | 13 | 171¶ | 216¶ | −43.7‡ (67.2) | 1.7 | Smoking, female sex (relative), male sex (absolute), low educational level, elevated CRP (relative) | ||
Triebner, 201732 | 36.2** | 19.7** | 648 | −14.1 (42.8) | Menopausal status, BMI | ||||
FEV1/FVC | |||||||||
Liao, 201526 | 47.4* (10.6) | 17 | 207* | 336* | −0.0029 (0.0023)* | Smoking, less versus more likely dust exposure | |||
FEV0.75 (mL) | |||||||||
Pelkonen, 2001(a)29 | 47.6 | 30 | 100 | −34.8 | 1.0 | Smoking | |||
Pelkonen, 2001(b)29 | 49.4 | 15 | 200 | −46.4 | 1.4 | Smoking | |||
PEFR (L/min) | |||||||||
Maselko, 200627 | 74 | 7 | 173 | 371 | −8.6 (30.3) | –8.6 (34.7) | 2.0 | 2.3 | Smoking |
Proctor, 200630†† | 83.2 (2.8) | 8 | 191 | 388 | −11.5 (2.2)§ | −6.6 (1.1)§ | 2.9 | 2.4 |
SDs were calculated from 95% CI by subtracting the highest from the lowest CI and dividing the result by 3.92.
*Based on estimates including smokers.
†Average derived from taking the midpoint value of each age group and calculating the overall mean age according to proportion in each group.
‡Estimates adjust for covariates including height and age.
§Mean (SE).
¶Estimates based on the assumption that there was an equal proportion of non-smokers and smokers who were male/female.
**Median.
††A non-linear relationship was also reported in the authors’ data analysis.
BMI, body mass index; CRP, C reactive protein; FEV0.75, forced expiratory volume in 0.75 s; FEV1, forced expiratory volume in 1 s; FVC, forced vital capacity; PEFR, peak expiratory flow rate.