. 2018 Sep 24;11:493–514. doi: 10.2147/DMSO.S146121

Table 4.

2PD pre- and post-DNS; mean ± SD and effect size (median value and range), where positive effect size value indicates improvement

Authors	Study type	Limb/group	n	Pre-DNS (mm)	Post-DNS (mm) at the nearest month (effect size)
Authors	Study type	Limb/group	n	Pre-DNS (mm)	3	6–12	18	24
DNS groups
Aszmann et al³⁴	Observational	DNS	8	16.0±4.4		12.3±4.6 0.8 (0.7-1.1)
Liao et al²⁸ (diffuse pain)	Observational	DNS	161	18.7± 1.7				7.3±1.5 7.1 (6.0-9.2)
Liao et al²⁸ (focal pain)	Observational	DNS	145	17.4± 1.9				6.4± 1.5 6.4 (5.5-8.4)
Rader²⁹	Observational	DNS	39	16.7	12.5	11.2
Wood and Wood³⁹	Observational	DNS	33	18.0±2.7	12.8±4.9 1.3 (1.2-1.8)
Zhang et al⁴⁰	Observational	DNS	560	9.5±2.0			6.7± 1.6 1.5 (1.3-2.0)
Average 2PD		DNS		12.8±4.6	12.8±4.9	12.3±4.6	6.7±1.6	6.9± 1.6
Average effect size					1.3	0.8	1.5	6.8
Control groups/limbs
Aszmann et al³⁴	Observational	Control limb	8	14.3±4.8		14.1±5.1 0.0 (0.02-0.04)
Liao et al²⁸	Observational	Control group	92	16.3±1.8				17.8± 1.7 −0.8 (0.7-1.1)

Abbreviations: 2PD, two-point discrimination; DNS, decompression nerve surgery.