A Multi-method Approach to Measuring Mastitis Incidence

This is the first of two papers describing a retrospective population-based survey of 273 women who initiated breastfeeding and whose babies were now six months old. It measured the incidence of mastitis and the impact of the women's experiences of managing mastitis on their reporting behaviour. The survey took place between January and May 2002. Based on a case definition of four primary symptoms, 56 women indicated they were either 'sure' or 'unsure' whether they had had mastitis. All these cases were included in estimating a cumulative incidence of 40 per cent (95 per cent CI 25-37 per cent). Incidence was highest at four and 12 weeks. Uncertainty of diagnosis was positively associated with effective self-management and not consulting a healthcare professional (p < 0.006). The study concluded that factors that influence reporting pattern are important determinants of incidence.