Response rates to repeat mailings of women living in the Seattle area who received their first mailing before July 1999
| . | First mailing . | Second mailing . | Third mailing . | P . |
|---|---|---|---|---|
| Total reached by mailinga | 18,380 | 15,547 | 10,753 | |
| Total responses (%)b | 1,436 (7.8) | 816 (5.2) | 239 (2.2) | <0.001 |
| Number randomized (%)c | 46 (3.2) | 10 (1.2) | 2 (0.8) | 0.003 |
| Mailings (costd) needed to randomize 1 participant | 401 ($76.60) | 3206 ($612.35) | 17,046 ($3,255.79) |
| . | First mailing . | Second mailing . | Third mailing . | P . |
|---|---|---|---|---|
| Total reached by mailinga | 18,380 | 15,547 | 10,753 | |
| Total responses (%)b | 1,436 (7.8) | 816 (5.2) | 239 (2.2) | <0.001 |
| Number randomized (%)c | 46 (3.2) | 10 (1.2) | 2 (0.8) | 0.003 |
| Mailings (costd) needed to randomize 1 participant | 401 ($76.60) | 3206 ($612.35) | 17,046 ($3,255.79) |
Number of women mailed minus the number of mailings returned by the post office.
Denominator for percentages is the total reached by mailing.
Denominator for percentages is the total number of responses.
In 1998 dollars, based on the bulk-rate of $0.191 per mailing when sending 3000 packets at one time.