Table 3.

Reference values

		Low symptoms severity		− 1 SD			Md			+ 1 SD		High symptoms severity
Scale	N	2.5%	5%	16%	30%	40%	50%	60%	70%	85%	95%	97.5%
Total	823	0	0	0	2	5	7	11	17	36	72	83
Physical		0	0	0	0	0	1	3	4	12	26	32
Emotional		0	0	0	0	1	2	3	5	10	15	18
Cognitive		0	0	0	0	0	1	2	4	10	21	25
Fatigue		0	0	0	0	0	1	2	4	8	12	14

N = 127 adolescents with chronic health conditions were not included in the reference values. 50% percentiles represent 50% of the distribution corresponding to the median (Md) and the mean of the distribution; SD standard deviation; values from − 1 standard deviation (16%, rounded up to the next integer) to + 1 standard deviation (85%, rounded up to the next integer) are within the normal range (i.e., not clinically relevant symptom severity); values below 16% indicate low symptoms severity (i.e., absence of PCSI-SR-13 symptoms) and values above 85% indicate high symptom severity (i.e., presence of clinically relevant PCSI-SR13 symptoms)