Table 16 Descriptive reports of adverse outcomes

Fadeyev et al. [61]

(33; 19 vs. 14)

Treatment group: 5 events; 26.3%

In the treatment group, 5/19 patients had various AEs during treatment (3 patients had more ventricular premature beats and 2 patients had an increased mean heart rate in conjunction with an increased number of ventricular premature beats). At the end of the follow-up period, one of the patients in the treatment group had an unstable episode of ventricular tachycardia.

AEs in the control group were not reported.

Liu et al. [64]

(136; 68 vs. 68)

Control group (0 events; 0.0%) vs. treatment group (9 events; 13.2%)

OR 21.87 (95% CI 1.25–383.87); p = 0.03

Absolute value (range), 0 fewer per 1000 (from 0 fewer to 0 fewer)

Adverse reactions included mild insomnia, mild diarrhea, mild paroxysmal supraventricular tachycardia, and palpitations.

Nagasaki et al. [69]

(95; 48 vs. 47)

Control group (0 events; 0.0%) vs. treatment group (0 events; 0.0%)

None of the patients experienced side effects such as arrhythmia, angina pectoris, or hypertension that would have required withdrawal or reduction of the dose of levothyroxine.

Stott et al. [73]

(737; 368 vs. 369)

Control group (103 events, 27.9%) vs. treatment group (78 events, 21.2%)

HR of 0.94 (95% CI of 0.88–1.0); p = 0.053

Absolute value (range), 14 fewer per 1000 (from 0 fewer to 29 fewer)

For serious AEs only

Zhao et al. [77]

(369; 210 vs. 159)

Control group (13 events; 8.2%) vs. treatment group (16 events; 7.6%)

OR 0.93 (95% CI 0.43–1.99); p ≥ 0.05

Absolute value (range), 5 fewer per 1000 (from 45 fewer to 69 more)

Adverse symptoms included palpitations, chest tightness, dizziness, perspiration, low back pain, and hunched back. No participant attempted to visit a physician due to adverse effects.