Table 2.

The characteristics of the studies included in this meta-analysis.

Study	Level of study	Group	Sex (M/F)	Age, mean ± SD (y)	Pain duration, mean ± SD	Herpes involved area	Intervention (V)	Last follow-uptime (m)	Outcome
Cheng-Fu Wan, 2021	RCT	S-PRF	23/35	69.96 ± 13.66 d	65.14 ± 18.53 d	Trigeminal	40	6	VAS, SF-36 score, mean dose of pregabalin, adverse events
		H-PRF	21/36	70.54 ± 14.02	67.28 ± 19.64 d		60 V to 100
Hongxi Li, 2021	RCT	S-PRF	10/16	64.15 ± 12.29	56.69 ± 13.70 d	Trigeminal	45	6	VAS, SF-36, treatment efficiency, adverse events
		H-PRF	12/14	66.62 ± 8.21	58.85 ± 16.62 d		65
Tao Song, 2019	RCT	Sham group	20/27	65.96 ± 13.66	63.14 ± 18.53 d	Trigeminal		6	VAS, SF-36, dosage of pregabalin, adverse events
		H-PRF	21/25	65.54 ± 13.28	59.28 ± 16.64 d		60 to 90
Bo Wang, 2020	RCT	S-PRF	13/19	71.42 ± 5.43	22.40 ± 5.46 d	Thoracolumbar	47.73 ± 2.45	3	NRS, SQS, gabapentin and tramadol doses, clinically meaningful PHN cases
		H-PRF	15/17	72.81 ± 5.92	23.20 ± 4.61 d		76.50 ± 5.61
Zhenkai Han, 2020	RCT	S-PRF	17/19	67.67 ± 6.77	3.08 ± 1.07 m	Thoracolumbar	45	12	VAS, SF-36, patient satisfaction, adverse events
		H-PRF	16/20	68.19 ± 10.42	3.38 ± 0.93 m		65
Shenshen Lin, 2021	RCT	Sham group	16/14	67.6 ± 10.6	16.0 ± 8.7 d	Neck, upper limbs, etc		3	VAS, PSQI, SF-36, use of tramadol and gabapentin, adverse events
		H-PRF	18/12	66.8 ± 8.4	15.2 ± 7.3 d		90 V–100