Characteristics of the cohorts
| Nedocromil | Salmeterol | Bambuterol | |
|---|---|---|---|
| Dates of studies | November 1986 to September 1988 | December 1990 to May 1991 | February 1993 to December 1995 |
| Total number of green forms posted | 20644 | 28019 | 18013 |
| Total number of green forms returned with usable data1-150 (% response rate) | 12294 (59.6) | 15407 (55.0) | 8098 (45.0) |
| Overall number of patient-months of exposure | 77674 | 172753 | 32926 |
| Men (% of cohort) | 6340 (51.6) | 7844 (50.9) | 3631 (44.8) |
| Women (% of cohort) | 5768 (46.9) | 7445 (48.3) | 4400 (54.3) |
| Sex not known | 186 (1.5) | 118 (0.8) | 67 (0.8) |
| Median age (years) (interquartile range) | 46 (24–62) | 55 (34–67) | 60 (38–72) |
| Recorded indication for study drug (%) | |||
| Asthma/wheeze | 7487 (60.9) | 10820 (70.2) | 4637 (57.3) |
| Chronic obstructive airways disease | 1247 (10.1) | 1816 (11.8) | 1209 (14.9) |
| Others† | 1336 (10.9) | 424 (2.8) | 1040 (12.8) |
| Unknown | 2224 (18.1) | 2346 (15.2) | 1212 (15.0) |
↵1-150 Final cohort; †others includes dyspnoea, bronchitis, cough, chest infection, emphysema, and bronchiectasis.