Effectiveness of a community-based support programme to reduce social inequality in exclusive breastfeeding: study protocol for a cluster-randomised trial

Table 3 Overview of quantitative data collection, source and timepoints

Outcome measures	Survey data						Register data
Sources	Mother					Partner	Register data
Time point since birth (PP)	One week	One month	Four months	Six months	Twelve months	One month
Primary
Exclusive breastfeeding four months (binary)			X				NCHR
Exclusive breastfeeding (continuous)	X	X	X				NCHR
Secondary
Readmission of infant to hospital related to nutrition	X	X					NPR
Experienced breastfeeding problems	X	X	X
Family’s relationship with health visitor	X	X	X			X
Maternal breastfeeding self-efficacy	X	X	X
EQ-5 D^*		X	X
Partial breastfeeding				X	X
Covariates
Age	X					X	SD
Education	X					X	SD
Occupation	X					X	SD
Civil status	X					X	SD
Smoking	X					X
BMI^**	X					X
Details about the birth (date, mode, infant’s weight)	X						BR
Attitude towards breastfeeding	X					X
Previous breastfeeding experience	X
Breastfeeding knowledge	X					X
Sense of support from partner	X
Assessment of support from health visitor	X					X

Abbreviations: BMI Body Mass Index, BR The Birth Register, NCHR The National Child Health Register NPR The National Patient Register, PP postpartum, SD Statistics Denmark
^*European Quality of life – 5 Dimensions (EQ-5D)
^**Calculated using self-reported weight and height

ISSN: 1471-2458