Detail | 1991 | 2002 |
---|---|---|
Note: Response rates have been calculated after excluding false positives as in the third Croydon study no attempt was made to interview subjects identified as false positives at initial phone contact. | ||
†66% random sample. | ||
‡In 1991 10 stopped wheezing at interview (interviewed as former wheezers). | ||
Population targeted | 3786 | 4246 |
Forms returned | 3070 | 3111 |
Response rate | 81% | 73% |
Wheeze in previous 12 months | 395 | 555 |
Sought for home interview | 395 | 366† |
False positives | 7 | 9 |
Sought for home interview excluding false positives | 388 | 357 |
Interview obtained | 312 | 198 |
Response rate | 80% | 55% |
Exclusions‡ | 10 | 0 |
After exclusions | 302 | 198 |