Protocol for the feasibility and acceptability of a brief routine weight management intervention for postnatal women embedded within the national child immunisation programme: randomised controlled cluster feasibility trial with nested qualitative study (PIMMS-WL)

Introduction
On average women retain 5-9kg one year after giving birth which can increase the risk of later obesity and chronic diseases. Some previous trials in this population have been effective in reducing weight, but are too intensive and costly to deliver at scale. There is a need for low-cost interventions to facilitate weight loss in this population.
Methods and analysis
The primary aim is to assess the feasibility of delivering a weight management intervention for overweight/obese postnatal women within child immunisation appointments. We will conduct a randomised controlled cluster feasibility trial with a nested qualitative study to assess study recruitment and acceptability of the intervention. GP practice (cluster) will be the unit of randomisation, with practices randomised to offer usual care plus the intervention or usual care only. 80 women will be recruited.
The intervention group will be offered brief support that encourages self-management of weight when attending child immunisation appointments. Practice nurses will encourage women to weigh themselves weekly and record this, and to make healthy lifestyle choices through using an online weight management programme. Women will be advised to aim for 0.5-1kg/week weight loss. At each child immunisation the nurse will assess progress by weighing women. The comparator group will receive a healthy lifestyle leaflet.
Data on weight, body fat, depression, anxiety, body-image, eating behaviours and physical activity will be collected at baseline and follow-up. Women and nurses will be interviewed to ascertain their views about the intervention. The decision to proceed to the phase III trial will be based on pre-specified stop-go criteria.
Ethics and Dissemination
Data will be stored securely at the University of Birmingham. Results will be disseminated through academic publications and presentations and will inform a possible phase III trial. The National Research Ethics Committee approved the study protocol.
Trial Registration number: ISRCTN12209332