Meta-analysis of routine calcium/vitamin D3 supplementation versus serum calcium level-based strategy to prevent postoperative hypocalcaemia after thyroidectomy

Background: The aim was to assess the effectiveness of routine administration of calcium +/- vitamin D3 compared with a serum calcium level-based strategy to prevent symptomatic hypocalcaemia after thyroidectomy.

Methods: RCTs comparing routine supplementation of calcium +/- vitamin D3 with treatment based on serum calcium levels measured after total thyroidectomy, published between 1980 and 2017, were identified in MEDLINE, Embase, LILACS and Google Scholar databases. Risk of bias was evaluated using the Cochrane Collaboration tool. Risk differences were calculated by random-effects meta-analysis. Meta-regression and cumulative meta-analysis were used to explore the best therapeutic approach.

Results: Fifteen studies with 3037 patients were included, and seven treatment comparisons were made. Routine supplementation with calcium + vitamin D3 offered a lower risk of symptomatic (risk difference (RD) -0·25, 95 per cent c.i. -0·32 to -0·18) and biochemical (RD -0·24, -0·31 to -0·17) hypocalcaemia than treatment based on measurement of calcium levels. The number needed to treat was 4 (95 per cent c.i. 3 to 6) for symptomatic hypocalcaemia. No publication bias was found; although heterogeneity was high for some comparisons, sensitivity analysis did not change the main results.

Conclusion: Routine postoperative administration of calcium + vitamin D3 is effective in decreasing the rate of symptomatic and biochemical hypocalcaemia.