P1192Is all hypothyroidism in patients on amiodarone caused by the drug or is a some simply a consequence of the intensive monitoring of TSH in an at risk population?
Bibliographic record
Abstract
Background: Hypothyroidism is common in the elderly. In the CHS, 16.5% of patients over the age of 65 years (mean age 72.7years) were diagnosed with hypothyroidism. The Canadian Thyroid Foundation has stated that 15% of Canadians >65 years have hypothyroidism and 24% entering a nursing home are diagnosed with or treated for hypothyroidism. Amiodarone is a very effective anti-arrhythmic agent but with potentially serious adverse reactions. Physicians familiar with the drug, accept hypothyroidism as a frequent consequence of Amiodarone therapy. Amiodarone is an Iodine based with a similar structure to Thyroxine. Thyroid abnormalities are a logical consequence of Amiodarone. The purpose of our investigation was to see if all hypothyroidism developed while on Amiodarone is due to the drug? Methods: Our database was searched for patients who had been prescribed Amiodarone. These were then compared to a similar (age and gender) cohort of coronary disease patients who had never been prescribed Amiodarone or any other anti-arrhythmic drug. In the control group, patients with any form of arrhythmia, valvular disease, pacemaker or previous ablation were excluded. Patients were diagnosed with hypothyroidism if they were taking thyroid medication. The unpaired t-test was used to determine differences between means and the Fischer’s exact test was used to determine differences between proportions. A P value <0.05 was considered statistically significant. Results: There were 360 Patients in both the Amiodarone and the control groups. The groups were well matched for Age (80.3±11.4 vs 80.9±7.3 years, P=0.4006) and Gender (M/F 221/139 vs 227/133, P=0.7008). There were 105 patients (29%) in the Amiodarone group who were taking thyroid replacement compared to 83 patients (23%) in the control group, (P=0.0746). On reviewing the TSH levels in 51 patients with normal baseline TSH and not already taking Thyroid replacement at baseline there were two distinct patterns, Group 1: 18 patients developed an elevated TSH requiring treatment within the first year, with most increases in TSH occurring in the first 6 months. Another 3 patients developed a high TSH during the second year. Group 2: 30 patients developed an elevated TSH requiring treatment ranging from 3-16 years following Amiodarone treatment with mean time of 7.1 ± 3.8 years and a median of 6 years. If one just considers the late development of hypothyroidism, there were 84/360 in the Amiodarone group and 83/360 in the control group, (P =NS, Fischer’s exact test). Conclusion: The early development of hypothyroidism during Amiodarone therapy is drug related. It is much less likely that the late development of hypothyroidism is related to Amiodarone, more likely it is just the emergence of a disease which is common in the elderly and which is diagnosed because of the intensive monitoring of thyroid function that occurs during Amiodarone monitoring.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.003 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.001 |
| Bibliometrics | 0.001 | 0.003 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.008 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".