Randomised controlled trial of the use of a modified postal reminder card on the uptake of measles vaccination.

OBJECTIVE To determine whether rewording postal reminder cards according to the "health belief model", a theory about preventive health behaviour, would help to improve measles vaccination rates. DESIGN A randomised controlled trial, with blind assessment of outcome status. Parents of children due for their first measles vaccination were randomised to one of two groups, one receiving the health belief model reminder card, the other receiving the usual, neutrally worded card. The proportion of children subsequently vaccinated in each group over a five week period was ascertained from clinical (provider based) records. SETTING A local government operated public vaccination clinic. PARTICIPANTS Parents of 259 children due for measles vaccination. MAIN RESULTS The proportion of children vaccinated in the health belief model card group was 79% compared with 67% of those sent the usual card (95% CI, 2% to 23%), a modest but important improvement. CONCLUSION This study illustrates how the effectiveness of a minimal and widely practised intervention to promote vaccination compliance can be improved with negligible additional effort.