Table 1 Study objectives, outcomes, criteria for success, and method of analysis
Objectives | Feasibility outcomes (trial) | Criteria for success | Method of analysis |
Maternal weight change (proposed primary endpoint for future definitive RCT) | Difference in percentage of maternal weight change between trial groups from antenatal booking to 12 months postnatally | Percentage of weight change/weight loss in kilogrammes | Estimated differences/95% CI calculated (significance at 5%) Pre-planned sub-group analysis by BMI category |
Recruitment and retention | Uptake/time to recruit 190 women from BMI categories of interest | Complete recruitment within 6 months | Descriptive |
Loss to follow-up under 30% at 12 months | Retain 130 women to 12 months | Descriptive | |
Explore influence of lifestyle information and Slimming World on lifestyle/health behaviours | Dietary intake, EPDS score, breastfeeding uptake and duration, sleep patterns, smoking, alcohol consumption, self-esteem, infant health, body image | High completion of all included measures at each follow-up point | N (%) for binary and categorical variables and mean (SD), or medians/geometric means for continuous variables |
Assess feasibility of collecting resource utilisation and cost data | Completion of EQ-5D-5L, Adult Service Use Schedule, relevant data from women’s maternity records | High completion of all included measures at each follow-up point | Multivariate/sensitivity analysis |
Objectives | Outcomes (process) | Criteria for success | Method of analysis |
Acceptability of trial process procedures | Reasons for taking part/dropping out, expectations, understanding of study aims, attendance at follow-up appointments, acceptability of surveys | Processes and procedures acceptable, high completion of follow-up measures | Framework method, descriptive |
Acceptability of intervention | Women commence and complete Slimming World sessions offered | Depth of understanding of barriers and facilitators to uptake and retention at sessions, so this can be maximised in a future trial | Framework method, descriptive |
Variation in Slimming World groups attended by women by date/time of day | Range of variation in Slimming World groups attended | Availability of data from Slimming World | Descriptive |
Sources of weight management support control group accessed/additional support intervention women accessed | Extent and type of weight management support used by control women, additional support used by intervention women | Risk of contamination re access to commercial weight management support by control group | Descriptive |