Ten studies containing 22 separate interventions were included.
Seven cognitive interventions were assessed, including educational pamphlets or brochures, telephone delivered scripted material, and interactive telephone counselling. The improvement in compliance ranged from 5 to 31%. Two RCTs of interactive telephone counselling (n=90 and 612) showed a statistically-significant difference (P<0.05) in effect size (23.8%, 95% confidence interval, CI: 3.8, 43.8 and 25.7%, 95% CI: 17.8, 33.6, respectively). There was some evidence to suggest that educational pamphlets or brochures might also improve compliance.
Six behavioural interventions were assessed, including reminders, transport incentives and other payment vouchers. A telephone reminder showed significant improvement in one RCT at the initial follow-up (n=433, effect size 17.9%, 95% CI: 8.8, 27.0) but not at the 6-month follow-up (n=77). Letters alone did not improve follow-up in one RCT (n=1,425). A letter and telephone reminder showed significant improvement in one RCT in women with any abnormal cancer screening result, not just Pap smears (n=393, effect size 20.8%, 95% CI: 13.1, 28.5).
One sociologic intervention was assessed. This comprised video-taped peer discussions containing a message about abnormal Pap smears and follow-up. This did not increase follow-up.
The findings from eight combined interventions in 3 studies (RCTs) were inconsistent.