The Impact of Natural Product Dietary Supplements on Patients with Gout: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Table 1

Characteristics of the included studies.

Author	Year	Country	Condition	Arms	Population	NPDS	Formulation	Control group	Evaluation criteria	Therapeutic efficacy
Shi et al. [25]	2008	China	Gout	4	107	Modified prescriptions of simiao pill	Pill	Indomethacin and benzbromarone	Guiding principle of clinical research on new drugs of traditional Chinese medicine	Joint arthralgia, erythema, and swelling, blood uric acid and gout recurrence↓
Renbin et al. [26]	2008	China	Gouty arthritis	2	120	Modified simiao tang	Decoction	Allopurinol tablet	An assemblage of guiding principles of clinical and preclinical research on new drugs	The index of swelling and pain in the joints, BUA, and CRP ↓
Song et al. [24]	2008	China	Gout	2	200	Weicao capsule	Capsule	Tong Feng Ding capsule	Diagnosis and curative effect standard of traditional Chinese medicine disease	Joint swelling and pain, laboratory indices↓
Zhang et al. [23]	2010	China	Acute gouty arthritis	2	67	Blood-letting cupping plus herbal medicine	Decoction	Diclofenac sodium enteric-coated tablets	The Budzyuski index of pain	Joint pain and swelling, BUA↓
Dalbeth et al. [28]	2012	New Zealand	Gout	3	120	SMP/GMP/G600	Powder	GMP, G600	The 10-point Likert scale	Gout flare, the severity of joint pain↓
Wang et al. [22]	2014	China	Acute gouty arthritis	2	176	Chuanhu antigout mixture	Decoction	Colchicine	—	Gout recurrence, CRP, AEs↓
Xie et al. [21]	2017	China	Intercritical and chronic gout	2	210	Compound tufuling oral liquid	Decoction	Placebo solution	—	The frequency of recurrent joint swelling and pain, BUA↓
Yu et al. [20]	2018	China	Gout with hyperuricemia	3	72	Yellow-dragon Wonderful-seed Formula	Decoction	Allopurinol group	SF-36	Joint pain, BUA, and CRP↓
Singh et al. [27]	2019	USA	Gout	2	84	Cherry extract	Capsule	Diet modification	—	Joint pain intensity↓, average pain in last 24 h↓

NPDS: natural product dietary supplement; CRP: C-reactive protein; BUA: blood uric acid; SMP: skim milk powder; GMP: glycomacropeptide; G600: G600 milk fat extract.