Table 3.

Table Depicting the Study Model, Therapy for Subacute Thyroidits, Therapy Outcome and Results of the Fifteen Articles Analyzed in This Systematic Review

S. No	Study	Aim of study	Study model	Therapy	Outcome of therapy	Post therapy R [R] and prognosis	Results and conclusions
1	Sencar ME, PUBL 2019, ANKARA, (TURKEY).17	Differentiate b/w therapeutic effects of steroids and NSAIDs in SAT.	Retrospective cohort study, Jan 2014 and Sept 2018. Sample size was 217.	1) Ibuprofen (NSAID) Pt No.: 126 Dose: 1800 mg in 3 doses Duration: 14 d 2) Methyl PSL (Steroid) Pt No.: 91 Dose: 48 mg in 2 doses. Tapering: 8 mg for 1st 4 wks and 4 mg for last wk Duration: 6 wks	Mean Rx duration for NSAID shorter than PSL as nonresponsive NSAID grp were shifted to steroids	NSAID: R in 7 Pts. PH in 9 Pts. Methyl PSL: R in 21 Pts. PH in 6 pts.	NSAIDs: less than 50% efficacy in pts. With ↑ ESR & ↑ CRP. PSL therapy Important in SAT pts. With Anti-TPO, ↑ ESR &↑ CRP to induce R & prevent PH. The total PH rate was 12.4%. This was seen to be linked to Anti-TPO Ab & Ibuprofen Rx. (p:0.03 and p:0.04)
2	Fatourechi V, PUBL 2003, OLMSTEAD COUNTY, MINNESOTA (USA)18	Determine the incidence of transient hypothyroidism and PH post Rx of SAT with NSAIDs and PSL alone or in combination along with the incidence of R.	Retrospective cohort study sample size: 94 [1960 to 1997]	1) NSAIDs alone: Pt no: 39 Mean duration: 35d 2) NSAIDs alone or with PSL: Pt No. 57 Dose: 40 mg PSL (mean dose) for 7 d tapering for 34 d (median) 3) PSL alone: Pt No.: 15 Dose: 40 mg PSL for 7 d tapering for 34 d 4) PSL alone or with other Rx Pt No.: 34 Dose: 40 mg PSL for 7 d followed by tapering for 34d 5) Acetaminophen Pt No.: 21 Duration:35 d 6) Thyroidectomy: 1 Pt.	NA	1) No difference in transient hypothyroidism during the early phase b/w PSL vs NSAID vs BOTH grp. 1) Early R 10% of pts. 2) Early hypothyroidism.: 34% 3) Late R 4% of pts. 4) Late hypothyroidism: 15% of pts. 5) Nodular goitre was seen in 5% of pts. 6) 5% a/w autoimmune disease 7) 11% of pts a/w non-thy cancers.	There is a ↑ incidence of transient hypothyroidism in the 1st year post Rx (34%) The PSL Rx grp had a ↑ rate of hypoth. on long-term follow-up (P < 0.05).
3	Duan L, PUBL. 2020 CHONGQING, CHINA9	Short term vs 6 wk PSN in the Rx of SAT: Randomised Control Trial (RCT).	RCT. Prospective single blind RCT Duration 24 wks Pts AUG 2013 to DEC 2014, Sample size: 50.	Randomly assigned to short-term (EXP grp) or 6-wk (CONTROL grp) 1) EXP GRP WK 1: 20 mg and 10mg PSN in morn and noon daily. WK 2: 400 mg celecoxib on d 1 and 200 mg twice daily for the next 6d CONTROL GRP: WK 1: 20mg and 10 mg PSN in morn and noon daily. WK 2: Taper by 5mg/wk from 2nd wk until withdrawal in 6th wk. All pts. given PPIS	Efficacy defined as no pain in thy, no clinical Sy, normalization of ESR and CRP. R: development of goitre with Tenderness, fever, and ↑ of markers during PSN tapering or at Rx end Primary end points: no sig difference in two grps in rates of efficacy and R.	R: - EXP Grp 3 pts had R during Rx and 4 after Rx. CONTROL Grp: 2 pts R During RX and 4 pts After RX. MANAGEMENT OF R: 10 mg PSN in morn and 10 mg in noon. Incidence of overt and SUBCLINICAL HYPOTHY: At diagnosis 86% During follow up 61% in both grps.	The Study demonstrated that both grps had similar rates of effects. The short-term Rx had fewer s/e eg Markers of bone turnover and BP. Short-term Rx with a may be an optional strategy for moderate-to-severe SAT.
4	Sato J, PUBL 2016, TOKYO, JAPAN12	Diff. b/w Rx effects of PSL and NSAIDs in SAT.	Retrospective study b/w 2008–2014. Sample size: 42	25 pts with PSL. dose of PSL was 15 mg 17 pts NSAIDs. loxoprofen at 180 mg/d	Time for normalisation of thy function: PSL GRP Mean – 25 d NSAIDs Mean 32 d Time for disappearance of initial sy PSL grp. Mean: 7 d NSAIDs grp Mean 21 d	R within two months of stopping drug PSL grp 3 pts. NSAIDs grp 1 pt No difference in the R rate b/w the two grps (p = 0.635).	PSL not only shortens the duration of resolution of sy but also reduces the time to normalisation of thy function
5	Kubota S, PUBL: 2013, KOBE, JAPAN.11	1) Determine if Initial Rx with 15 mg PSN daily is sufficient for most SAT pts.	Prospective Cohort Study SAMPLNG b/w Feb 2005 - Jan 2008. Final sample size: 219.	Initial dose: 15 mg/d of PSL. Tapering: 5 mg every 2 wks Duration: variable. Follow up every 2w,	SHORT MED. GRP.113 Recovered within 6wks. LONG MED. GRP: Recovered in 12wks or more. 61pts in 7–8 wks Longest RX: 40 wks: 7pts needed increased PSL dose:	The Rx protocol had 15 mg/d of PSL as the initial dose for SAT, with tapering by 5mg every 2 wks, and was effective and safe for Japanese pts. However, 20% of pts. with SAT needed longer than 8 wks to recover from the inflammation.
6	LI F PUBL CHINA, 201819	To retrospectively analyse the effects and safety of PV extract and low-dose PSL in SAT	Retrospective cohort study Sept 2013 -May 2016 sample size: 87	The control grp= PSL 20 mg/dy as initial dose tapering 5mg every 3 wks The experimental grp. = 10 mg/dy of PSL+ 1.4 g/dy PV tapering of 5mg every 3 wks		GRP. 1 – PSL ONLY R Rate (6months): 4 (9.5%) Incidence of transient hypothyroidism: 2 (4.8%) GRP. 2 – PSL WITH PV R Rate (6months): 2 (4.4%) Incidence of transient hypothy: 1 (2.2%)	The results have shown that the new combination of PSL and PV alleviated fever, pain, thy swelling more efficiently and had a lower R rate. This could be a result of the immunosuppressive and antiviral effect of PV.
7	ARAO T, PUBL. 2015, JAPAN14	To determine the PSL Dosing Regimen for Rx of SAT	Retrospective cohort study 26 pts. Jan 2004 - July 2013	The non-R grp and The R Grp both received PSN doses b/w 15 mg/dy to 30 mg/dy Analysis of the 2 grp showed no differences in the initial PSL dose.	R was diag. in 4 out of 26 pts. With an estimated R rate of 15.3%	4 pts. experienced R at The time when the PSL dose was 5 mg/dy. The No. of dys required tapering the PSL dose to 5 mg/dy was sigly shorter in the R grp	The SAT R rate was 15.3%. There was no sig difference in the initial PSL dose b/w the non-R and R grps. However, for the primary endpoint, sig differences were found b/w the two grps in time required for tapering PSL to 5 mg/dy (non-R: 44.3 ± 15.3 dys, R: 19.0 ± 11.9 dys,
8	Mizukoshi T 2001, PUBL, JAPAN13	To confirm the R rate of PSL and to compare the findings b/w R and non-R grps.	Retrospective cohort study b/w Jan 1997 to Dec 1998 Sample Size - 36	PSL was administered at 30 mg or 25 mg daily, and tap. by 5 mg per wk, for 5 or 6 wks	Most pts. Became euthyroid by the second wk after the initial presentation of thyrotoxicosis.	Among 36 pts. 8 recurred (22%)	The R rate of SAT with treated PSL is about 20%. A modified protocol should be further investigated to decrease the R of SAT
9	ZHAO N, PUBL. 2020, SHENYANG (CHINA)15	To explore the early indicators of hypothyroidism and the final changes in thy Volume in SAT pts.	Prospective cohort study Sample size: 61	NSAIDS: 46 pts. PSL: 6 pts, NSAID± PSL: 7 No therapy: 2	1 out of 13 pts. On PSL Rx had hypothyroidism, 19 of48 pts. who did not receive PSL had hypothyroidism	Pts. With clinical hypothy. And subclinical hypothy. after the acute SAT received LT4 therapy (dose 12.5 or 25 µg/dy)	In conclusion, during the 2 years of follow-up, the gland volume of SAT pts. especially with hypothy, were smaller than those of healthy controls after the acute stage of the disease.
10	Saklamaz A. 2017, PUBL, TURKEY20	To compare the treatment options on the development of permanent hypothyroidism in SAT patients.	Retrospective cohort study from medical records of sat between 2010 to 2015 Sample size:81	Patients classified into treatment groups: NSAID (n = 33) Steroid (n = 29) NSAID+steroid (n = 19) and 1 year outcome noted		All patients had tsh level return back to baseline. No permanent hypothy. Seen in either of the 3 treatment groups.	Treatment drug option did not affect the permanent hypothyroidism one year after in our SAT patients.
11	Benbassat CA 2007 PUBL ISRAEL21	To identify predictive factors of clinical outcome of SAT	Retrospective case series between 1999 to 2005. Sample size 56 pts.	10 pts.received no treatment, 43 pts.received treatment {NSAID (n = 25), steroids) n = 18)} 3 pts. were missing	Hypothy. Phase documented in 31 pts. Mean duration of disease was 77 days. Shorter duration of disease in pts. Given glucocorticoids when compared with NSAIDS. But short-term outcome between treated and untreated remains the same.	6 pts. Remained permanently hypothy. Peak FT4 level was positively correlated with highest TSH level and disease duration.	SAT follows and unpredictable clinical course hardly affected by clinical features or Rx
12	Forkert IO. 2021, PUBL Ukraine10	To compare the efficiency of intrathyroidal steroid injection with respect to oral steroid intake in SAT patients	RCT Between 2019–2021 Sample size 32 patients	32 pts. Randomly divided into 2 equal groups of 16. 1st grp received 2 intrathyroid steroid injection,2nd grp got oral PSL	Pts in grp 1 showed faster USG result compared to grp 2, a ↑ ESR, CRP drop at corresponding weeks measured.no side effects were noted in grp 1. 2nd grp experienced side effects like weight gain (n = 6), glucose intolerance (n = 5), HTN (n = 4), irregular menses (n = 2)	All 32 patients recovered fully and no incidence of PH or R	Intrathyroid steroid therapy is safer faster and better tolerated by pt.s when compared with oral PSL.
13	Hepsen S 2021 PUBL Turkey16	To evaluate difference between low dose and high dose steroid treatment	Retrospective observation study for 1 year, a total of 91 patients included	44 patients received 16 mg methylprednisolone (low dose) 47 patients received 48 mg methylprednisolone dose (high dose)	Recovery achieved in all patients Treatment duration needed to be extended for 1 (2.1%) and 6 (13.6%) of the patients in the 48-mg and 16-mg Methylprednisolone groups, respectively.48-mg Methylprednisolone group had a higher SAT recurrence rate than the 16-mg group.	Permanent Hypothyroidism developed in 5 (10.6%) of patients in the 48-mg MPS and 3 (6.8%) in the 16-mg MPS group	Low dose steroid therapy is sufficient to achieve complete therapy. No difference is observed with respect to treatment response and hypothyroidism rates between high and low dose steroid groups. High dose steroid group have a higher recurrence rate of SAT.
14	Bahadir ÇT 2022 PUBL Turkey22	Aimed to evaluate the factors affecting recurrence of SAT especially with regards to treatment	Retrospective study, includes 137 patients from jan 2008 to jan 2020	72 patients received steroid therapy while 65 patients had received NSAIDS According to patient records	Risk of recurrence was higher in those with steroid therapy (p = 0.015)	Sixty-five (47.4%) patients were treated with NSAIDs, and 72 (52.6%) patients were treated with steroids. Of 137 patients, 12 (8.8%) had recurrence and the remaining 125 (91.2%) patients had	The risk of SAT recurrence was higher with steroid therapy than with NSAIDs. Patients who had mild thyrotoxicosis need a longer duration of treatment as they had higher recurrence rates
15	Martinez DS, 2003 PUBL USA23	To evaluate the effects of using sodium ipodate and sodium iopanoate as treatment for SAT	Retrospective study with 10 patients with SAT	10 SAT patients received sodium ipodate and sodium iopanoate	Hyperthyroidism symptoms controlled and improved without any evidence of relapse of SAT after withdrawal of cholecystography agents.	No side effects of treatment with oral cholecystography agents.	sodium ipodate and sodium iopanoate are safe and effective in treatment of hyperthyroidism symptoms in SAT and prevent relapse of SAT

Abbreviations: SAT, subacute thyroiditis; b/w, between; No., number; PUBL, published; NSAIDS, non-steroidal anti-inflammatory drugs; pts, patients; pt, patient; ESR, erythrocyte sedimentation rate; CRP, C reactive protein; Thy, thyroid; USG, ultrasonography; Sy, symptoms; wks, weeks; wk, week; grp, group; grps, groups; PSL, prednisolone; PSN, prednisone; Rx, treatment; d, days; R, recurrence; PH, post therapy hypothyroidism; Anti TPO, anti thyroid peroxidase; Ab, antibody; I, iodine; Jan, January; Sept, September; Phy, physical; Lab, laboratory; FT4, free thyroxine; FT3, free triiodothyronine; TSH, thyroid stimulating hormone; hypoth., hypothyroidism; a/w, associated with; ↑, high; ↓, low; PSN, prednisone; EXP, experimental; morn, morning; BP, blood pressure; NA, not applicable; PV, Prunella vulgaris; sig, significant; effect, effectiveness; s/e, side effects; HTN, hypertension; MED, medication.