Table 3.
Clinical data by baseline levels of TSH. Baseline TSH was not measured in 99 patients, there was no record of TSH estimation or otherwise in 20 patients, and baseline levels were not submitted in a further 11 patients.
| TSH level (mIU/l) | |||||
|---|---|---|---|---|---|
| Clinical data | <0.2 (n=6) | 0.2–4 (n=53) | >4 (n=1066) | Total (n=1125) | P value |
| Diagnostic circumstancesa, n (%) | |||||
| Suspected hypothyroidism | 1 (16.7) | 29 (54.7) | 892 (83.7) | 922 (82.0) | <0.001 |
| Detection of goiter | 1 (16.7) | 8 (15.1) | 157 (14.7) | 166 (14.8) | NS |
| Other known thyroid diseaseb | 6 (100.0) | 25 (47.2) | 154 (14.4) | 185 (16.4) | 0.0057 |
| Etiology of hypothyroidism, n (%) | |||||
| Not reported | – | – | 4 | 4 | |
| Autoimmune thyroiditis | 1 (16.7) | 14 (26.4) | 703 (66.2) | 718 (64.0) | <0.001 |
| Iatrogenic causec | 5 (83.3) | 29 (54.7) | 213 (20.1) | 247 (22.0) | <0.001 |
| Other non-iatrogenic caused | – | 10 (18.9) | 146 (13.7) | 156 (13.9) | NS |
| Mean (s.d.) interval from determination of TSH to the start of the treatment, days | 28.2 (35.0) | 29.8 (30.5) | 16.3 (22.9) | 17.0 (23.5) | <0.001 |
| Positive for anti-thyroid antibodies (%) | |||||
| Anti-thyroperoxidase | 20.0 | 24.5 | 49.1 | 47.8 | 0.0024 |
| Anti-thyroglobulin | 20.0 | 16.7 | 35.9 | 35.0 | 0.0034 |
NS, not statistically significant.
More than one response could be given for each patient.
Thyroid nodular disease.
Includes surgery (38%), radioiodine therapy (12%), treatment with anti-thyroid drugs (12%), combinations of radioiodine therapy and anti-thyroid drugs (2%), and other treatments (36%).
Causes recorded in more than two patients were ‘unknown’ (45%), subclinical hypothyroidism (9%), investigation ongoing (8%), goiter (6%), old age (4%), thyroid hypoplasia (3%), thyroid atrophy (3%), pregnancy (2%), and family history (2%). Causes recorded in one or two patients were: iodine deficiency, emotional shock, craniopharyngioma, central hypothyroidism, multinodular thyroid dystrophy, alcohol and tobacco abuse, hematocele, central hypothyroidism, deficiency-induced hypothyroidism, familial hypothyroidism, chronic kidney disease, pituitary insufficiency, menopause, thyroid nodules, secondary hypothyroidism, primary hypothyroidism, involutional thyroid, thyroiditis, non-autoimmune thyroiditis, de Quervain's subacute thyroiditis, and viral thyroiditis.