Evaluating the effectiveness of cervical cancer screening invitation letters.

OBJECTIVE

The objective of this study was to evaluate the effectiveness of an invitation letter on cervical screening participation among unscreened women 30 to 69 years of age.

METHODS

A cluster randomized trial design was used in which unscreened women (n=31,452) were randomized by the forward sortation area (FSA) of their postal code to an intervention group that was sent an invitation letter (n=17,068) or a group that was not sent an invitation letter (n=14,384).

RESULTS

Six months after the letters were mailed, 1,010 women in the intervention group (5.92%) and 441 women in the control group (3.06%) had a Pap test. After adjusting for variables that have previously shown to influence screening participation, women who were sent an invitation letter were significantly more likely to have had a Pap test in the next 6 months compared with women who were not sent an invitation letter (odds ratio [OR]=2.60, 95% confidence interval [CI] 2.09-3.35, p<0.001). Overall, the effectiveness of the invitation letter improved with increasing age (p=0.02).

CONCLUSIONS

Sending invitation letters increased cervical screening participation but because the overall effect was small, additional strategies that remove barriers to screening for unscreened women are also necessary.