Rate of transient hypoparathyroidism will be assessed in terms of percentage of participants with day 1 serum PTH level of < 10 pg/ml.

1 participant in the Arm II(CND) was a screen failure. Arm III(SOC) data was not collected for this outcome measure as outcome is a comparison of complication rates between TT and CND arms and does not apply to SOC arm participants. The SOC arm was added later as comparison for the qualitative aims only.

Post-operative serum calcium (mg/dL) at Day 12

1 participant in the Arm II(CND) was a screen failure. Arm III(SOC) data was not collected for this outcome measure as outcome is a comparison of complication rates between TT and CND arms and does not apply to SOC arm participants. The SOC arm was added later as comparison for the qualitative aims only.

Total calcium consumption in first 2 weeks (total mg). Participants were given calcium symptom logs in which to record their calcium consumption between surgery and their first preoperative follow up appointment, approximately two week.

19 participants in CND arm, 22 in 'no CND' arm returned their calcium symptom log to study staff at the end of the postoperative follow-up period. Missing data is due to participants losing/forgetting to return their calcium symptom logs/lack of clarity in their handwritten log entries. This may also have led to limited reliability/accuracy of the data we were able to collect. SOC arm data was not collected as outcome is a comparison of complication rates between TT and CND arms, N/A to SOC arm.

Number of participants with hypocalcemia symptoms and symptom severity in first two weeks, as defined by presence of clinically significant symptoms of hypocalcemia.

Clinically significant symptoms defined as 1 or more episodes of symptoms of hypocalcemia per day for multiple days, symptoms leading to calls to provider for assistance with managing and/or symptoms leading to escalation of dosage of prescribed medications to treat symptoms of hypocalcemia

In Arm II (CND) 1 participant was lost to screen failure, 1 self-withdrew. Arm III(SOC) data was not collected for this outcome measure as outcome is a comparison of complication rates between TT and CND arms and does not apply to SOC arm participants. The SOC arm was added later as comparison for the qualitative aims only.

Mean number of occurrences of mild (severity 1 - 2) and severe (severity 3 - 5) hypocalcemia symptoms. Participants were asked to record hypocalcemia symptoms between surgery and first postoperative follow-up at approximately two weeks in their provided calcium symptom logs and rank severity on scale of 1 (mild) to 5 (severe).

Missing data is due to participants losing/forgetting to return their calcium symptom logs/lack of clarity in their handwritten log entries. This may also have led to limited reliability/accuracy of the data we were able to collect. SOC arm data was not collected as outcome is a comparison of complication rates between TT and CND arms, not applicable (N/A) to SOC arm.

Requirement for calcium and calcitriol at Month 6 (or, if laboratory values at visit reveal calcium < 8 mg/dL and PTH <15 pg/ml)

In Arm II (CND) 1 participant was lost to screen failure, 1 self-withdrew, 1 was lost to follow up. Arm III(SOC) data was not collected for this outcome measure as outcome is a comparison of complication rates between TT and CND arms and does not apply to SOC arm participants. The SOC arm was added later as comparison for the qualitative aims only.

In Arm II (CND) 1 participant was lost to screen failure, 1 self-withdrew, 1 was lost to follow up. Arm III(SOC) data was not collected for this outcome measure as outcome is a comparison of complication rates between TT and CND arms and does not apply to SOC arm participants. The SOC arm was added later as comparison for the qualitative aims only.

Post-operative serum calcium (mg/dL) at Month 6

In Arm II (CND) 1 participant was lost to screen failure, 1 self-withdrew, 1 was lost to follow up. Arm III(SOC) data was not collected for this outcome measure as outcome is a comparison of complication rates between TT and CND arms and does not apply to SOC arm participants. The SOC arm was added later as comparison for the qualitative aims only.

The rate of transient and permanent hypocalcemia will be determined by assessing the following:

I. Post-operative serum calcium (mg/dl) and PTH (pg/ml) at Day 12 and Month 6 II. Total calcium consumption in first 2 weeks (total gm) III. Hypocalcemia symptoms in first 2 weeks (average episodes/day) IV. Hypocalcemia symptom severity scale (range 1-5) V. Requirement for calcium and calcitriol at Month 6 (or, if laboratory values at visit reveal calcium < 8 mg/dL and PTH < 15 pg/ml

Data will be analyzed using the methods described above.

The rate of voice and swallowing problems will be determined by assessing the following:

I. Phonation threshold pressure, in centimeters of water II. Dysphonia severity index (DSI) score (+5 to -5) III. Grade Roughness Breathiness Asthenia Strain (GRBAS) score (0-3) IV. Voice quality parameters as measured by Consensus Auditory-Perceptual Evaluation of Voice (CAPE-V) (0-100 on visual analog scale) V. Vocal fold vibratory and movement parameters as measured by stroboscopy assessment (1-4) VI. Glottal function index score VII. Penetration-Aspiration score as measured by videofluoroscopic swallow study (0-8)

Data will be analyzed using the methods described above.

The degree to which quality (QOL) is compromised will be determined by assessing the following:

I. Short Form Health Survey (SF-12) Mental Composite Scale (MCS) score II. Short Form Health Survey (SF-12) Physical Composite Scale (PCS) score III. European Organization for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire (QLQ) Core-30 (C30) score IV. Thyroid Cancer Specific Quality of Life (ThyCA-QOL) score V. 10-item Eating Assessment Tool (EAT-10) dysphagia inventory score VI. Voice Handicap Index (VHI) score VII. Themes and codes from interview transcripts assessed using qualitative research methods

Data will be analyzed using the methods described above.

Clinical recurrence rates will be determined by assessing the following:

I. Percent of patients with a recombinant thyroid-stimulating hormone (rTSH) stimulated thyroglobulin level < 1 ng/ml one year after surgery II. Unstimulated thyroglobulin level prior to beginning week 6 radioactive iodine treatment III. Stimulated thyroglobulin at the time of week 6 radioactive iodine treatment IV. Incidence of unstimulated thyroglobulin > 1 ng/mL at 6 months V. Incidence of stimulated thyroglobulin > 2 ng/mL at 1 year VI. Incidence of biopsy-proven disease identification on neck ultrasound or iodine-131 (I-131) uptake up to 5 years post-surgery

Data will be analyzed using the methods described above.

The degree to which accurate quality of life (QOL) measures can be extracted from patient interview narratives using natural language process techniques will allow for the development of computer algorithms that convert patient narrative text into simple quality of life measures. Data will be analyzed using the methods described above.