Background Missed clinic appointments cause significant wastage of health resources worldwide. The majority of cases who DNA appointments are young and of lower socio-economic status and, conversely, are most likely to carry STIs. Several interventions aimed at reducing DNA appointments such as reminder SMS texts and letters have been studies internationally. Our UK STI department uses interventions such as monthly displays of DNA appointments, SMS reminders and removal of booking privileges to reduce DNA rates. The objective of this study was to assess whether introducing a verbal missed appointment warning at the time of booking has an effect on subsequent DNA and cancellation rates.

Method 108 patients over 16 years old were recruited in this RCT to show a 25% difference between the groups. Within the first arm the patients were advised that if they did not cancel their appointments in advance and subsequently DNA’ed then they would be obliged to attend a walk-in service in the future. In the second arm the warning was removed. The DNA rates from these two arms were compared initially to each other and then to other previously studied interventions.

Results Interim analysis of results shows a fall in the DNA rates with those who received a verbal warning message at the time of booking matching SMS text and letter reminders rates seen in published data.

Conclusion With financial constraints affecting STI clinics worldwide, it is essential to consider low-cost methods aimed at reducing DNA rates. Whilst we have shown a warning message to be effective, it is also inexpensive and introduction of such a warning system would be beneficial in resource-limited settings.