Supplementary file 1_Effects of parent-administered massage-based multimodal interventions on health outcomes in preterm infants: a systematic review and meta-analysis.docx

Parental psychological outcomes were synthesized narratively because of substantial heterogeneity. Risk of bias was assessed with RoB 2, and certainty of evidence with GRADE.</p>Results<p>Twenty-four randomized controlled trials were included. Moderate-certainty evidence indicated that massage-based interventions were associated with higher odds of breastfeeding or human-milk feeding at discharge (OR 5.42, 95% CI 2.44–11.94), shorter time to full oral feeding (MD −2.04 days, 95% CI −3.95 to −0.13), and shorter hospital length of stay (MD −4.68 days, 95% CI −7.79 to −1.57).

Weight-gain velocity was greater in the primary meta-analysis (MD 5.55 g/day, 95% CI 1.71–9.38), but certainty was low, heterogeneity was very high (I² = 97.87%), significant small-study effects were detected, and the trim-and-fill adjusted estimate was attenuated and no longer statistically significant (MD 3.45 g/day, 95% CI −1.67 to 8.56). Parent-related psychological findings were generally favorable but were supported by low-certainty evidence.

Effects on length growth, head-circumference growth, and motor development were not statistically significant; certainty for length and head-circumference growth was very low.</p>Conclusion<p>Moderate-certainty evidence suggests that parent-administered massage-based interventions may improve selected feeding outcomes and reduce hospital length of stay in preterm or low-birth-weight infants. The effect on weight-gain velocity remains uncertain because of very high heterogeneity, low certainty of evidence, and possible small-study effects.

However, many interventions were multimodal and heterogeneity was substantial; therefore, the findings should be interpreted as effects of parent-delivered developmental-care interventions that include massage rather than massage alone, and the independent effect of massage requires confirmation.</p>Systematic review registration<p>crd.york.ac.uk/PROSPERO/view/CRD420261435482, identifier CRD420261435482.</p>