Table 1.
Characteristics of the 23 studies included in a meta-analysis to evaluate the risk factors for postoperative hypocalcaemia after thyroidectomy in adult patients.3,9,10,15–34
| Author | Country | Study design | Patientsn | Rate of postoperative hypocalcaemia, % | NOS score | Risk factors |
|---|---|---|---|---|---|---|
| Liu et al., 202015 | USA | Retrospective cross-sectional analysis | 126 766 | 30-day follow-up after surgery: 19.1% | 7 | Age, female, vitamin D deficiency, concurrent lateral neck dissection, concurrent central neck dissection, intraoperative parathyroid, recurrent laryngeal nerve injury, magnesium disorders |
| 1-year follow-up after surgery: 4.4% | ||||||
| Lale et al., 201916 | Turkey | Retrospective case control | 818 | Permanent hypocalcaemia (>1 year): 26.7% | 6 | Female, specimen weight, substernal localization, cervical lymph node dissection (CLND) |
| Transient hypocalcaemia (calcium level <8 mg/dl at 24 and 72 h after thyroidectomy): 1.7% | ||||||
| Carvalho et al., 201917 | Brazil | Retrospective cohort study | 1347 | Hypocalcaemia: 21% | 6 | Neck dissection, malignancy, sex, age, preoperative total calcium, preoperative parathyroid hormone (PTH); preoperative vitamin D, central compartment dissection |
| Wang W et al., 201918 | China | Retrospective cohort study | 242 | Hypocalcaemia: 60% | 6 | Sex, extent of surgery, hypoparathyroidism, lymph node dissection, hypomagnesemia, preoperative calcium |
| Falch et al., 201819 | Germany | Retrospective case study | 702 | Postoperative biochemical hypocalcaemia (48 h): 22.8% | 5 | Symptomatic hypocalcaemia, female, parathyroid reimplantation, surgery time (≥189 min), thyreostatic drug therapy |
| Persistent biochemical hypocalcaemia (>6 months): 6.8% | ||||||
| Docimo et al., 20179 | Italy | Retrospective case control | 328 | Symptomatic hypocalcaemia: 7.9% | 7 | Malignant pathology, central compartment neck dissection (CCND) |
| Transient hypocalcaemia: 14.6% | ||||||
| Permanent hypocalcaemia: 0.6% | ||||||
| Luo et al., 201720 | China | Retrospective case control | 304 | Biochemical hypocalcaemia: 26.9% | 5 | Female, postoperative hypomagnesaemia, postoperative iPTH < 1.6 pmol/l, relative decline of iPTH > 70% |
| Symptomatic hypocalcaemia: not reported | ||||||
| Wang X et al., 201721 | China | Retrospective case control | 237 | Biochemical hypocalcaemia: 52.3% | 6 | Bilateral CCND, modified radical neck dissection (MRND), parathyroid gland autotransplantation, hypoparathyroidism, hypomagnesaemia |
| Symptomatic hypocalcaemia: 33.8% | ||||||
| Cho et al., 201622 | Korea | Retrospective cohort study | 1030 | Transient hypocalcaemia: 28.2% | 6 | Age, female, central neck dissection (CND), MRND, extent of CND (bilateral), operation time, implant of parathyroid gland, parathyroid gland in pathology |
| Permanent hypocalcaemia: 2.6% | ||||||
| Nellis et al., 201623 | USA | Retrospective cohort study | 620 744 | Hypocalcaemia 6% | 8 | Magnesium disorder, phosphate disorder, female, age, Medicaid payor status, thyroid cancer, total thyroidectomy, neck dissection, recurrent laryngeal nerve injury, high-volume surgeon |
| Garrahy et al., 201610 | Ireland | Retrospective cohort study | 201 | Biochemical hypocalcaemia: 22.9% | 7 | Cancer diagnosis, central neck dissection, hypomagnesaemia, inadvertent parathyroid resection |
| Symptomatic hypocalcaemia: 12.4% | ||||||
| Bove et al., 201624 | Italy | Retrospective cohort study | 142 | Temporary hypocalcaemia: 33% | 6 | Substernal goitre |
| Permanent hypocalcaemia: 2.8% | ||||||
| Lee et al., 201525 | Korea | Retrospective case study | 134 | Laboratory preoperative calcaemia: 39% | 6 | Age, female, body mass index, preoperative calcium, preoperative PTH, vitamin D (< 20 ng/ml), vitamin D (< 10 ng/ml), selective neck dissection, incidental parathyroidectomy |
| Symptomatic preoperative calcaemia: 19% | ||||||
| Al-Khatib et al., 201526 | Saudi Arabia | Retrospective cohort study. | 213 | Laboratory hypocalcaemia: 19.7% | 6 | Postoperative serum PTH, preoperative serum 25(OH)D < 25 nmol/l |
| Clinical hypocalcaemia: 17.8% | ||||||
| Praženica et al., 201527 | Ireland | Prospective cohort study | 788 | Temporary hypocalcaemia: 23.9% | 8 | Sex, age, preoperative diagnosis benign, biclamp haemostasis, thyroid gland weight, substernal extension, tracheal deviation, operation time, multinodular goitre, Graves’ disease, Hashimoto thyroiditis, thyroid cancer, incidental parathyroidectomy |
| Symptomatic hypocalcaemia: 14.0% | ||||||
| Diez et al., 201328 | Spain | Prospective cohort study | 113 | Hypocalcaemia: 38.90% | 6 | Preoperative vitamin D < 15 ng/ml, postoperative PTH < 13 pg/ml |
| Baldassarre et al., 201229 | USA | Retrospective case study | 118 375 | Hypocalcaemia: 5.50% | 8 | Age, female, ethnicity, Hispanic, Asian or Pacific islander, native American, total thyroidectomy, thyroidectomy with unilateral neck dissection, thyroidectomy with bilateral neck dissection, complete substernal thyroidectomy, partial substernal thyroidectomy, substernal thyroidectomy, isthmectomy, partial thyroidectomy, length of stay (per day), nonteaching hospital, malignant neoplasm of thyroid gland |
| Turanli et al., 200930 | Turkey | Retrospective cohort study | 417 | Permanent hypocalcaemia: 7.7% | 7 | Incidental parathyroidectomy, extrathyroidal soft tissue invasion |
| Erbil et al., 200931 | Turkey | Prospective cohort study | 200 | Symptomatic hypocalcaemia: 73% | 6 | Age (> 50 years); preoperative serum 25-OHD level < 15 ng/ml |
| Asymptomatic hypocalcaemia: 27% | ||||||
| Wang Y et al., 201732 | China | Retrospective case study | 278 | Hypocalcaemia: 27.30% | 8 | Age (years), lateral lymph node dissection, lobectomy plus isthmusectomy versus lobectomy, near-total thyroidectomy versus lobectomy, total thyroidectomy versus lobectomy, injected versus non-injected, female, preoperative PTH levels |
| Aqtashi et al., 201733 | Switzerland | Retrospective cohort study | 34 | Hypocalcaemia: 33% | 6 | Operation interval, preoperative PTH, preoperative calcium |
| Lin et al., 20173 | Taiwan | Retrospective case study | 3186 | Hypocalcaemia: 30.90% | 7 | Age, female, multituberous goitre, Graves’ disease, malignant tumours, total thyroidectomy, reoperation, central cervical lymph node, thyroid malignancy |
| Tongol et al., 201634 | Philippines | Retrospective case study | 242 | Symptomatic hypocalcaemia: 10.74% | 7 | Age, sex, thyroid disease (toxic, nontoxic or malignant), thyroid gland weight in grams, presence concomitant complication of thyroidectomy Hoarseness and/or haematoma, type of surgery (total thyroidectomy), neck dissection, duration of surgery in hours, inadvertent parathyroidectomy |
| Asymptomatic hypocalcaemia: 1.24% |
NOS, Newcastle–Ottawa Scale.