Study considerations
HYPOCALCAEMIA, POSTOPERATIVE HYPOPARATHYROIDISM, RECRUITMENT
This was a pragmatic study. The surgical procedure, including autotransplantation of parathyroid tissue as required, and treatment of biochemical or symptomatic hypocalcaemia, was undertaken according to local policies, reflecting a variety of contemporary clinical routines. The four centres that participated in the study are identified by letters A–D.Postoperative PTH concentration is known to be the best predictor of postoperative hypoparathyroidism, with a sensitivity of 69–100 per cent in predicting hypocalcaemiaBased on an α of 80 per cent and β of 5 per cent, it was calculated that 280 patients (140 in each arm) needed to be included to show a reduction from 15 to 5 per cent for the primary outcome, low level of PTH on the first postoperative day. With an expected recruitment of approximately 70 per cent of eligible patients, and allowing for drop-outs owing to change of surgical strategy before or during surgery, protocol violations, and loss to follow-up, at least 400 patients needed to be invited to participate.Randomization was performed 1 : 1 in blocks of 10 through the Eurocrine