Around 5-10% of hypothyroid patients continue to experience profound and sometimes disabling symptoms, including fatigue, depression and impaired cognition, in spite of being adequately replaced biochemically.
The use of liothyronine and natural desiccated thyroid extract is controversial for reasons of costs, a lack of evidence of additional benefit over levothyroxine alone, and potential safety concerns.
We recruited self-selecting patients with the help of a national thyroid charity who reported to be clinically resistant to levothyroxine despite being biochemically euthyroid. They were invited to complete an on-line, validated multi-attribute health utility instrument, the EuroQol EQ-5D-5L questionnaire and accompanying EQ-VAS (visual analogue scale). EQ-5D-5L index values (utilities, a preference-weighted measure of patients’ health valuation) were estimated based on the EQ-5D-5L cross walk value set for the UK.
Responses were available from 54 people. Mean (SD, minimum, maximum) EQ-5D-5L utility was 0.53 (0.23, -0.00, 0.84); and EQ-VAS was 49.3 (17.2, 5.0, 90.0). 44/54 (81%) individuals reported having moderate problems in at least one attribute, most often their ability to perform usual activities, and anxiety or depression; 24/54 (44%) reported severe problems; and 6/54 (11%) reported extreme problems.
Reported health utilities in these individuals are comparable to those reported by patients with lung cancer, or acute cerebrovascular disease and rank in the bottom decile of 100 chronic diseases.
A lack of proven effective treatment and a large unmet need indicates that now is the right time for a definitive clinical trial to address this important area of uncertainty