Maintaining the quality of a complex behavioural intervention to promote early presentation of cancer in a randomised controlled trial
Amanda Ramirez
Guys, Kings and St Thomas School of Medicine, London, UK
Purpose
We have evaluated a complex behavioural
intervention to raise cancer awareness and thereby promote early
presentation in older women with breast cancer in a randomised controlled
trial. The intervention has been shown to be effective at raising breast
cancer awareness among older women in the medium term. The intervention
is a scripted ten-minute one-to-one interaction with a health professional. We
aimed to achieve and maintain sufficient quality of delivery of this
intervention throughout the trial.
Method
We developed a quality assurance package including a manual for
delivery, training, performance feedback and quality criteria for judging
quality of delivery, both content and style. We applied the quality criteria to
the 229 interventions delivered during the trial. We calculated the proportion
of variability in outcome (breast cancer awareness measured using a
questionnaire at one month) attributable to variation in health professional.
We examined the association between intervention delivery, outcome and missing
outcome data.
Results
Ninety eight per cent of interactions scored over 80%
for content, and 66% over 80% for style. During the trial, quality of content
and style was consistently maintained, except in those by the two professionals
who delivered fewer than ten interventions. One
per cent of the variation in outcome was attributable to different
professionals. We found no association between quality of delivery and outcome,
although the women receiving the 15% most poorly conducted interventions were
10% less likely respond to the outcome questions.
Conclusion
This
intensive quality assurance package achieved a high quality of delivery of the
complex behavioural intervention in this trial. If the intervention is to be
successfully implemented in the NHS we need to develop and test a more
stream-lined sustainable quality assurance framework to ensure consistent
quality of delivery on a larger scale.