Table 3

Response rates to repeat mailings of women living in the Seattle area who received their first mailing before July 1999

First mailingSecond mailingThird mailingP
Total reached by mailinga18,38015,54710,753
Total responses (%)b1,436 (7.8)816 (5.2)239 (2.2)<0.001
Number randomized (%)c46 (3.2)10 (1.2)2 (0.8)0.003
Mailings (costd) needed to randomize 1 participant401 ($76.60)3206 ($612.35)17,046 ($3,255.79)
  • a Number of women mailed minus the number of mailings returned by the post office.

  • b Denominator for percentages is the total reached by mailing.

  • c Denominator for percentages is the total number of responses.

  • d In 1998 dollars, based on the bulk-rate of $0.191 per mailing when sending 3000 packets at one time.