Maintaining the quality of a complex behavioural intervention to promote early presentation of cancer in a randomised controlled trial


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Amanda Ramirez

Guys, Kings and St Thomas School of Medicine, London, UK


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.

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.

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.

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.