Nystrom 1988

Methods	1. Generation of allocation sequence: No description 2. Allocation concealment: No description 3. Blinding: Double‐blinding 4. Sample size calculation: No description 5. Loss to follow‐up: 3 (during the first study period) 6. Intention‐to‐treat analysis: No description 7. Similarity between groups: Yes
Participants	1. Inclusion criteria: Women with SH ‐ FT4, T3, T4 normal serum levels; TSH response (delta TSH > 30 mU/L) upon TRH administration. 2. Exclusion criteria: Cardiovascular disease 3. Characteristics (Age (mean (SD)), gender, ethnicity, other): Women, aged 51‐73 years
Interventions	1. Intervention in experimental group (including number of patients, dosage, mode of administration, duration of treatment): L‐thyroxine tablets 50 mcg daily for the first 2 weeks, 100 mcg daily for the next 2 weeks, and 150 mcg daily for the rest of the study period. 2. Intervention in control group 1 (including number of patients, dosage, mode of administration, duration of treatment): Placebo tablets
Outcomes	1. Symptoms: Physical tiredness, mental lethargy, dry skin, cold intolerance, dry hair and constipation. 2. Clinical neurological examination: Psychometric tests 1‐ Identical forms test according to Thurstone 2 ‐ Bingley's memory test 3 ‐ Reaction time 3. Cardiac function: Systolic time intervals LVET, PEP, PEP/LVET, pulse rate 4. Creatine kinase activity 5. Procollagen‐III‐peptide 6. Sex‐hormone binding globulin 7. Thyroid Hormones 8. Cholesterol
Notes	1. Setting: Göteborg, Sweden 2. Funding source: Supported by grants from "Torsten Söderbergs och Ragnar Söderbergs stiftelse" and the Swedish National Association against Heart and Chest Disease.
Risk of bias
Bias	Authors' judgement	Support for judgement
Allocation concealment?	Unclear risk	B ‐ Unclear