Call and recall for cervical cancer screening in a developing country: A randomised field trial

A randomised field trial was used to assess Mexican women's response to a m ailed invitation for a Papanicolaou test. A sample of 4,802 women, 20 to 64 years old, chosen at random from the Mexican Social Security Institute Reg ister were randomly assigned to an intervention and to a control group. A l etter of invitation and a reminder were sent to the intervention group, A l etter was also sent to the control group at the end of the follow-up period (8.5 weeks) in order to compare the response among women who received a le tter in both groups. Cumulative incidence and incidence rates were used to determine the response and the speed of response, respectively. The respons e among women who had received the letter was 33.5% (efficacy) in the inter vention group, while 5.9% (p<0.001) in the control group attended a Papanic olaou test. For the total of women invited, the response was 20.1% (effecti veness) and 3.3% (p<0.001), respectively. The response was greater in rural areas (rural vs. urban/suburban; p = 0.002) and eldest women (50-64 vs. 20 -49; p = 0.02), The response rate was 7 times grater in the intervention th an in the control group (RR = 7.1; 95% CI 5.4-9.4; p < 0.001), A mailed inv itation to have a Papanicolaou test substantially increases attendance by w omen who receive it. A mailed reminder improves results. This strategy coul d be implemented in addition to the ones already in use, mainly among rural and elderly women. Int. J. Cancer 87: 869-873,2000, (C) 2000 Wiley-Liss, I nc.