Chi 2005.
| Methods |
Type of study: randomised controlled clinical trial Allocation: 1:1 Intervention model: parallel group superiority design Masking: no blinding of patients or personnel Primary purpose: treatment of Graves' disease |
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| Participants |
Condition: Graves' disease Enrolment: 340 in total Inclusion criteria: diagnosis of Graves disease and informed consent to study Exclusion criteria: 1) Previous recurrent hyperthyroidism 2) Large thyroid tumour that prohibited subtotal thyroidectomy 3) Less than 2.5 x 1 x 1 cm thyroid remnant (not suitable for further surgery) 4) Minimum follow‐up period less than 3 months (early loss to follow‐up) Diagnostic criteria: Graves' hyperthyroidism diagnosed with clinical manifestations, TFT, thyroid scan, histology (postoperatively) |
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| Interventions |
Number of study centres: 1 Treatment before study: patients were rendered euthyroid with propylthiouracil or methimazole (treatment duration from one month to 144 months) Titration period: none Intervention(s): bilateral subtotal thyroidectomy Comparator(s): unilateral total lobectomy and contralateral subtotal thyroidectomy |
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| Outcomes |
Primary outcome(s): 1. Postop thyroid status (TFTs, TSH) Secondary outcome(s): 2. Hypoparathyroidism 3. Recurrent laryngeal nerve injury 4. Wound haematoma/bleeding Other outcome(s): ‐ |
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| Study details |
Run‐in period: none Study terminated before regular end (for benefit/because of adverse events): no Study start date: 1998 Study completion date: 2002 |
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| Publication details |
Language of publication: English Funding: not stated Publication status: peer‐reviewed journal, full article |
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| Stated aim for study | To compare the results of bilateral subtotal thyroidectomy and unilateral total and contralateral subtotal thyroidectomy in control of hyperthyroidism in Graves' disease | |
| Notes | ||
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Unclear risk | Quote from publication: "patients who underwent subtotal thyroidectomy for hyperthyroidism were prospectively randomised into two groups" Comment: randomisation after consent for surgery; method of sequence generation not specified |
| Allocation concealment (selection bias) | Unclear risk | Comment: not clearly stated whether allocation concealment took place |
| Blinding of participants and personnel (performance bias) Objective outcomes | High risk | Quote from publication: "surgery was performed by one surgeon. The standard surgical technique of subtotal thyroidectomy under general anaesthesia with intact inferior thyroid artery was used" Comment: all operations performed by single surgeon; surgeon could not be blinded to group allocation; no blinding of participants |
| Blinding of participants and personnel (performance bias) Subjective outcomes | High risk | Quote from publication: "surgery was performed by one surgeon. The standard surgical technique of subtotal thyroidectomy under general anaesthesia with intact inferior thyroid artery was used" Comment: all operations performed by single surgeon; surgeon could not be blinded to group allocation; no blinding of participants |
| Blinding of outcome assessment (detection bias) Objective outcomes | Unclear risk | Quote from publication: " T3 and T4 were measured with radioimmunoassay kit ... total calcium level was measured routinely one day after operation... permanent hypoparathyroidism was defined as symptomatic hypocalcaemia for more than 6 months" Comment: (1) evaluation of thyroid function: laboratory standard tests; (2) operation time: not blinded; (3) blood loss: not blinded; (4) postoperative calcium level: laboratory standard tests; (5) recurrent laryngeal nerve palsy: assessed by laryngoscopy, not clear if blinded |
| Blinding of outcome assessment (detection bias) Subjective outcomes | Unclear risk | No subjective outcomes are measured in this study |
| Incomplete outcome data (attrition bias) Objective outcomes | Low risk | Quote from publication: "we excluded patients for whom the follow up period was less than 3 months" Comment: outcome data reported for all 340 participants; however participants lost at an early stage of follow‐up were excluded from study, therefore not intention‐to‐treat analysis |
| Incomplete outcome data (attrition bias) Subjective outcomes | Low risk | Quote from publication: "we excluded patients for whom the follow up period was less than 3 months" Comment: outcome data reported for all 340 participants; however participants lost at an early stage of follow‐up were excluded from study, therefore not intention‐to‐treat analysis |
| Selective reporting (reporting bias) | Unclear risk | Comment: participants lost at an early stage of follow‐up were excluded from study, therefore not intention‐to‐treat analysis; mortality not reported |
| Other bias | Low risk | Comment: none detected |