Thyroid Health Outcomes Registry for Surgery

Proportion of index thyroid operations followed by at least one clinically verified postoperative complication within 30 days, using prespecified event definitions, multiple routine-care sources where available, and expert adjudication. Complication types are reported separately and may include hypocalcemia/hypoparathyroidism, recurrent laryngeal nerve dysfunction, hematoma/bleeding, infection, chyle leak, unplanned reoperation, organ injury, readmission, and other clinically relevant events.

The number of unique participants who undergo at least one unplanned surgical reoperation related to the index thyroid operation within 30 days will be divided by the number of participants with ascertainable 30-day follow-up and multiplied by 100. Planned completion thyroidectomy is classified separately and is not counted as an unplanned reoperation.

All-cause death within 30 days of the index thyroid operation, using available in-hospital and post-discharge sources.

Persistent postoperative vocal-fold dysfunction attributable to surgery at 12 months, with preoperative dysfunction, tumor invasion, and intentional nerve resection considered separately.

Persistent postoperative parathyroid dysfunction at 12 months based on prespecified biochemical and treatment criteria.

Among index operations with a valid final pathology report, the number of operations assigned to each prespecified mutually exclusive diagnosis category will be divided by the total number of operations with valid final pathology and multiplied by 100. Categories are differentiated thyroid carcinoma, medullary thyroid carcinoma, other malignant thyroid neoplasm, benign thyroid neoplasm, non-neoplastic thyroid disease, and other or indeterminate pathology.

Among participants with differentiated thyroid carcinoma and an ascertainable 12-month assessment, the number meeting the prespecified definition of structural or biochemical persistent disease at 12 months will be divided by the total number with an ascertainable assessment and multiplied by 100. A participant is counted once if either the structural or biochemical persistence criterion is met.

The number of index operations assigned to each prespecified mutually exclusive thyroid resection category will be divided by the total number of eligible index operations and multiplied by 100. Categories are hemithyroidectomy, initial total thyroidectomy, completion thyroidectomy, and other thyroid resection.

Available direct medical cost for the index thyroid-surgery hospitalization will be summarized as the median with interquartile range in Russian rubles among hospitalizations with recorded cost data. Structurally unavailable cost values will be reported as missing and will not be automatically imputed.

Among operations with morphologically confirmed primary thyroid carcinoma and an ascertainable pathologic T category, the number of operations in each standardized pT category will be divided by the total number of operations with an ascertainable pT category and multiplied by 100. The pT category is derived from the final pathology report using the prespecified staging rules.

Among operations with morphologically confirmed primary thyroid carcinoma and an ascertainable pathologic N category, the number of operations in each standardized pN category will be divided by the total number of operations with an ascertainable pN category and multiplied by 100. The pN category is derived from the final pathology report using the prespecified staging rules.

Among participants with differentiated thyroid carcinoma who have no evidence of persistent disease after initial treatment, the number who develop a new structural or biochemical recurrence will be divided by the number with evaluable follow-up and multiplied by 100. A participant is counted once if either the structural or biochemical recurrence criterion is met.

The number of eligible index thyroid operations that include a central neck lymph node dissection will be divided by the total number of eligible index thyroid operations and multiplied by 100. Central and lateral neck dissections are classified separately according to the prespecified operation-classification rules.

The number of eligible index thyroid operations that include a lateral neck lymph node dissection will be divided by the total number of eligible index thyroid operations and multiplied by 100. Central and lateral neck dissections are classified separately according to the prespecified operation-classification rules.

Among participants who undergo an initial hemithyroidectomy and are eligible for longitudinal trajectory assessment, the number who subsequently undergo a planned completion thyroidectomy within 12 months will be divided by the number with ascertainable 12-month surgical follow-up and multiplied by 100. Planned completion surgery is not classified as an unplanned reoperation.

At each annual data freeze, the number of available values across the prespecified required data elements and eligible operation records will be divided by the total number of expected values for those elements and records and multiplied by 100. Missing, not assessed, not applicable, structurally unavailable, and contradictory values will remain distinguishable in the data-quality report.

At each validation cycle, the number of eligible operation records referred for manual clinical review because of missing, conflicting, ambiguous, or rule-discordant information will be divided by the total number of eligible operation records evaluated in that cycle and multiplied by 100.

At each annual data freeze, each of the 13 Core Outcome Set for Differentiated Thyroid Carcinoma domains will be classified using a prespecified binary readiness rule. A domain is analytically resolvable only when its definition, eligible population, assessment window, data source, and participant-level outcome status can be determined for the planned analysis. The number of resolvable domains will be divided by 13 and multiplied by 100.