Validation of the Self-Assessment of Treatment Questionnaire among Patients with Postherpetic Neuralgia

Table 9

Known-groups validity: t-tests of SAT scores by NPRS pain level at baseline (pooled dataset; 𝑁=698)¹.

SAT	Baseline NPRS pain level
	High pain (𝑛=172)	Low pain (𝑛=526)	𝑃-value
	Mean (SD)	Mean (SD)
(1) Pain relief	0.4 (1.0)	0.7 (0.9)	0.001
(2) Activity level	0.2 (0.8)	0.4 (0.8)	0.013
(3) Quality of life	0.4 (0.8)	0.5 (0.8)	0.015
(4) Undergo treatment again	1.0 (1.2)	1.0 (1.2)	0.841
(5) Compared to previous treatment	0.4 (1.1)	0.5 (1.1)	0.080
SAT treatment effect subscale (Items 1, 2, and 3)	1.0 (2.3)	1.6 (2.3)	0.002
SAT treatment satisfaction subscale (Items 4 and 5)	1.3 (1.9)	1.5 (2.0)	0.275

NPRS: Numeric Pain Rating Scale; SAT: Self-Assessment of Treatment; SD: standard deviation.
¹Known-groups validity was assessed using t-tests to evaluate whether SAT items and subscale scores discriminated between patient groups by baseline pain level (high, low pain). Pooled dataset included data from two clinical trials, Studies C116 (𝑁=349) and C117 (𝑁=349).