Table 2 Characteristics of the studies participants’

Dev, 2023 [22]

87 patients

18 to 50 years

5 male – 82 females

The study included patients with episodic migraines diagnosed with subclinical hypothyroidism and negative anti-thyroid peroxidase antibody levels.

Patients with thyroid disease, abnormal neurological examinations, pregnancy, chronic illnesses affecting thyroid hormone levels, and regular drug intake.

Filipchuk, 2022 [31]

111

Mean age of patients with episodic migraine: (36.22 +/- 11.28); mean age of patients with chronic migraine (40.43+/- 11.28)

92.5% females (Episodic migraine), 93.2% females (chronic migraine)

Migraine patients and those receiving a stable dose regimen of levothyroxine for at least 6 months and considered euthyroid (corrected) if hypothyroidism was present

Patients under evaluation for possible hypothyroidism, or those in the dose-titration process, were excluded

Hepp, 2018 [32]

Equal number of adherent and non-adherent to levothyroxine (LT4) (159314)

Equal to and older than 18 years

female adherent"73.9%, non-adherent:75.9%

Patients have two separate claims for hypothyroidism (identified by ICD-9-CM of 243.xx or 244.xx, except 244.2x and 244.3x)

between 1 January 2012 and 31 December 2014 and at least

one prescription for levothyroxine (LT4) filled over that same

time horizon

Patients younger than age 18 as of the index date or if they were diagnosed with thyroid cancer

(ICD-9-CM of 193.xx) or pregnancy (ICD-9-CM of

630.xx–679.xx, V22.xx, V23.xx, V30.xx–V39.xx or V72.42) at any

time from the start of the pre-period through the end of the

post-period.

Lage, 2020 [33]

2340 treated with levothyroxine, 1108 untreated

32.76 ± 4.80 years

All females

Women ages 18–49 years who were identified as both hypothyroid and pregnant in 2014 were included in the study

Patients with thyroid cancer or those without continuous insurance coverage during their pregnancy were excluded from the analyses.