Objectives: To determine the effectiveness of three recruitment strategies to encourage women to attend for an initial mammography screen, and to compare results with similar service studies. Interventions were: (1) an invitation letter; (2) two invitation letters; and (3) an invitation letter plus a follow-up telephone call.

Methods: All women aged 50–54 years in two BreastScreen New South Wales (BSNSW) Screening and Assessment Service catchment areas (n=3,144) were recruited from the Australian Electoral Roll and randomised to the four groups. Response rates for each intervention were compared relative to standard practice (one invitation letter) at 12-weeks follow-up. Marginal cost-effectiveness for each condition was calculated. Other similar randomised trials were also meta-analysed.

Results: The screening rate for two letters was 8.5% (OR=1.61, 95% CI 1.08-2.40) and 7.8% (OR=1.46, 95% CI 0.97-2.18) for one letter plus a telephone call, compared with 5.5% for standard practice (one letter) (OR=1.00). The response rate in the one letter plus a phone call group was 13.3% (OR=2.65, 95% CI 1.76-4.00) for women where a phone number was located.

Conclusion: Initial screening rates after a 12-week follow-up were significantly higher in the women receiving a second invitation letter, compared with standard practice (one letter). Marginal cost-effectiveness favoured the two-letter approach.

Implications: A follow-up invitation letter is more cost-effective than one invitation letter plus a follow-up telephone call in the BSNSW program. However, an invitation letter plus follow-up phone call is more cost-effective in recruiting women to BSNSW only if a phone number is located.