Efficacy of patient letter reminders on cervical cancer screening - A meta-analysis

OBJECTIVE: To perform a meta-analysis on existing randomized controlled tri als to investigate the efficacy of patient letter reminders on increasing c ervical cancer screening using Pap smears. METHODS: A search was conducted for all relevant published and unpublished studies between the years 1966 and 2000. Eligibility criteria included rand omized controlled studies that examined populations due for Pap smear scree ning. The intervention studied was in the form of a reminder letter. The Ma ntel-Haenszel method was used to measure the summary effect of the interven tion. A test for homogeneity using the Mantel-Haenszel method was performed . RESULTS: Ten articles fulfilled the inclusion criteria, including one unpub lished study. The test for homogeneity showed evidence of heterogeneity (ch i (2) = 31, 9 df, P < .001). An analysis for causes of heterogeneity was pu rsued. Division into subpopulations based on socioeconomic status resolved the heterogeneity (chi (2) = 5.2, 8 df, P = .75). The studies evaluating th ose in lower socioeconomic groups had a smaller response (odds ratio [OR], 1.16; 95% confidence interval [CI], 0.99 to 1.35) than those studies using mixed populations (OR, 2.02; 95% CI, 1.79 to 2.28). The pooled odds ratio s howed that patients who received the intervention were significantly more l ikely to return for screening than those who did not (OR, 1.64; 95% CI, 1.4 9 to 1.80). CONCLUSIONS: Patient reminders in the form of mailed letters increase the r ate of cervical cancer screening. Patient letter reminders have less effica cy in lower socioeconomic groups.