Should a letter followed by a written reminder vs. a letter alone be used for inviting asymptomatic women to organised population-based breast cancer screening programmes?

The GDG supported a conditional recommendation for using letters plus written reminders in women between the ages of 50-69 as it judged that the benefits measured by the increase in participation in screening (an adequate outcome for this age group) would outweigh the undesirable effects of some women receiving a reminder when they had perhaps already made an informed decision not to participate in screening, as well as the moderate costs of the intervention.

The GDG noted that for women between the ages of 50 and 69, in whom screening is strongly recommended, the balance would favour the intervention because participation rate is an appropriate outcome. Participation rate was not considered an appropriate outcome for the other age ranges. For women in the age groups, 45-49 and 70-74, outcomes such as confidence and satisfaction of the woman in making an informed decision are crucial and the GDG advises interpretation of this intervention in the context of the recommendations on screening age ranges (please see point 3 in the implementation considerations).

• The GDG noted that it is easy to measure the additional costs of a reminder letter, which were assumed to be lower than the costs of the initial letter.
• The comparison evaluated for this recommendation needs to be interpreted in the context of the other comparisons of methods for inviting women to screening programmes evaluated by the GDG.
• It is noted that for age groups where the recommendation made by the GDG for screening is conditional (45-49 and 70-74 age groups) informed decision-making is crucial for implementation, and there would be concern about increasing inappropriate screening with this intervention. Where the GDG made a strong recommendation for screening in women between the ages of 50 and 69, this intervention is recommended as this intervention is desirable to increase participation in screening.

• The GDG recommends research on the effect of this intervention on other important outcomes such as informed decision-making, particularly for women where a conditional recommendation was made (45-49 and 70-74).
• Research on the best modality for inviting women in the age ranges where a conditional recommendation was made (45-49 and 70-74).
• Research evaluating the use of electronic messages including e-mail, social media and SMS as compared to paper letters for invitation to screening.