Table 3.

Correlations between Pain Interference Index (PII) (n = 27) and Patient Reported Outcome Measurement Information System Pediatric-25 Profile v1.1 (PROMIS-25) (n = 28)

Variable	PROMIS-25 2	Mobility	Anxiety	Depressive symptoms †	Fatigue	Peer relationships †	Pain interference
PII 1
Schoolwork		rs = −0.20 p = 0.310	rs = 0.50 p = 0.003**	rs = 0.49 p = 0.012*	rs = 0.43 p = 0.023*	rs = −0.54 p = 0.004**	rs = 0.51 p = 0.006**
Leisure activities		rs = −0.51 p = 0.006**	rs = 0.43 p = 0.024*	rs = 0.54 p = 0.005**	rs = 0.39 p = 0.043*	rs = −0.23 p = 0.270	rs = 0.58 p = 0.001**
Time with friends		rs = −0.50 p = 0.007**	rs = 0.41 p = 0.031*	rs = 0.51 p = 0.008**	rs = 0.47 p = 0.012*	rs = −0.37 p = 0.060	rs = 0.58 p = 0.001**
Mood		rs = −0.43 p = 0.025*	rs = 0.77 p < 0.001**	rs = 0.72 p < 0.001**	rs = 0.36 p = 0.058	rs = −0.56 p = 0.003**	rs = 0.54 p = 0.003**
Physical activities		rs = −0.32 p = 0.100	rs = 0.20 p = 0.310	rs = 0.23 p = 0.250	rs = 0.10 p = 0.580	rs = −0.077 p = 0.70	rs = 0.52 p = 0.005**
Sleep		rs = −0.38 p = 0.049*	rs = 0.52 p = 0.005**	rs = 0.54 p = 0.004**	rs = 0.31 p = 0.110	rs = −0.41 p = 0.038*	rs = 0.60 p = 0.001**

Spearman’s correlation coefficient (r_s) was calculated between PII (n = 27) and PROMIS-25 (n = 28). Significant at p < 0.05 (⁕ < 0.05, ⁕⁕ < 0.005) and r > 0.37. ¹ PII consists of a self-rating from 0 to 6, where 0 means “not at all” and 6 “very high” pain interference during six activities: schoolwork, leisure activities, time with friends, mood, physical activities, and sleep. ² PROMIS-25 is a self-rating instrument with the domains mobility, anxiety, depressive symptoms, fatigue, peer relationships and pain interference. The rating is on a scale from 0 to 4 where 0 means never and 4 always. † Two missing answers for depressive symptoms and one for peer relationships