Fig. 3.

Mantel–Haenszel statistical method with random-effects analysis model and mean difference for continuous variables as output only for included observational studies and RCT, and funnel plots assessing respective variance

Forest plots analysing crude event numbers between between robotic nipple-sparring mastectomy and conventional nipple-sparing mastectomy. a Operating time (in minutes). b Hospital stay (in days). c Blood loss (in millilitres). RNSM, robotic nipple-sparing mastectomy; CNSM, conventional nipple-sparing mastectomy; M-H, Mantel–Haenszel; SE, standard error; MD, mean difference.