| Baseline characteristic | Valid N | Control group | Valid N | Intervention group |
|---|---|---|---|---|
| Age (years), median (IQR) | 76 | 9.5 (8.3–11.3) | 76 | 9.1 (8.1–11.2) |
| Female | 76 | 46 (60.5) | 76 | 51 (67.1) |
| Rome diagnosisa | 76 | 76 | ||
| FAP | 29 (38.2) | 31 (40.8) | ||
| IBS | 35 (46.1) | 38 (50.0) | ||
| AM or FD | 10 (13.2) | 6 (7.9) | ||
| Not fulfilling Rome criteria | 2 (2.6) | 1 (1.3) | ||
| School level | 76 | 76 | ||
| Primary education | 63 (82.9) | 62 (81.6) | ||
| Secondary education | 12 (15.8) | 14 (18.4) | ||
| Vocational education | 1 (1.3) | — | ||
| Pain duration (years), median (IQR) | 70 | 2.6 (1.4–4.7) | 72 | 2.1 (0.7–4.5) |
| History at paediatricianb | 69 | 19 (27.5) | 72 | 17 (23.6) |
| School absence | 76 | 38 (50.0) | 76 | 43 (56.6) |
| Pain severity, median (IQR) | 76 | 6.0 (4.0–7.0) | 76 | 5.0 (4.0–7.0) |
| Abdominal pain, median (IQR) | ||||
| Pain intensity score | 67 | 12.0 (7.0–14.0) | 73 | 10.0 (7.0–15.0) |
| Pain frequency score | 67 | 11.0 (6.0–16.0) | 73 | 9.0 (7.0–17.0) |
| Health-related quality of life, median (IQR) | ||||
| Physical wellbeing | 76 | 47.1 (41.1–55.9) | 76 | 47.1 (41.1–54.9) |
| Psychological wellbeing | 76 | 48.9 (42.0–58.2) | 76 | 48.9 (43.3–57.4) |
| Moods and emotions | 76 | 41.5 (34.6–48.6) | 76 | 43.9 (36.2–51.3) |
| Self-perception | 76 | 52.3 (44.7–61.1) | 76 | 49.1 (44.2–61.1) |
| Autonomy | 76 | 51.0 (47.2–57.1) | 76 | 51.0 (45.7–57.1) |
| Parent relations and home life | 76 | 52.1 (47.0–58.5) | 76 | 52.1 (46.9–58.5) |
| Social support and peers | 76 | 53.0 (46.4–60.4) | 76 | 50.7 (46.4–55.4) |
| School environment | 76 | 52.1 (43.8–57.0) | 76 | 52.1 (43.8–62.5) |
| Social acceptance (bullying) | 76 | 50.6 (38.3–58.8) | 76 | 44.8 (39.3–58.8) |
| Financial resources | 76 | 62.9 (49.9–65.0) | 76 | 59.3 (51.9–65.0) |
| Pain beliefs, median (IQR) | ||||
| Pain threat | 75 | 2.2 (1.7–2.6) | 76 | 2.2 (1.5–2.7) |
| Problem-focused coping potential | 75 | 1.5 (0.8–2.0) | 76 | 1.3 (0.7–2.0) |
| Emotion-focused coping potential | 75 | 2.3 (1.8–3.0) | 76 | 2.3 (1.8–3.0) |
| Anxiety score, median (IQR) | 75 | 12.0 (8.0–18.0) | 76 | 11.0 (7.0–17.0) |
| Depression score, median (IQR) | 75 | 3.0 (2.0–4.0) | 76 | 3.0 (1.0–5.0) |
| Somatisation score, median (IQR) | 75 | 13.0 (7.0–24.0) | 76 | 13.5 (7.5–20.8) |
| Sleep self-report | ||||
| Q1: Do you fall asleep in about 20 minutes? | 75 | 76 | ||
| Usually (5–7)/week | 26 (34.7) | 24 (31.6) | ||
| Sometimes (2–4)/week | 24 (32.0) | 27 (35.5) | ||
| Rarely (0–1)/week or never | 25 (33.3) | 25 (32.9) | ||
| Q2: Do you wake up at night when your parents think you are asleep? | 75 | 76 | ||
| Rarely (0–1)/week or never | 47 (62.7) | 48 (63.2) | ||
| Sometimes (2–4)/week | 16 (21.3) | 17 (22.4) | ||
| Usually (5–7)/week | 12 (16.0) | 11 (14.5) | ||
| Q3: Do you feel sleepy during the day? | 75 | 76 | ||
| Rarely (0–1)/week or never | 38 (50.7) | 38 (50.0) | ||
| Sometimes (2–4)/week | 28 (37.3) | 28 (36.8) | ||
| Usually (5–7)/week | 9 (12.0) | 10 (13.2) | ||
| Treatment expectations, median (IQR)c | ||||
| Treatment effect NRS-11, child | 72 | 7.0 (6.0–8.0) | 74 | 7.0 (5.0–8.0) |
| Treatment effect NRS-11, parent 1 | 76 | 7.0 (6.0–8.0) | 75 | 7.0 (6.0–8.0) |
| Treatment effect NRS-11, parent 2 | 71 | 7.0 (6.0–8.0) | 69 | 7.0 (5.0–8.0) |
| Treatment preference, child | 73 | 75 | ||
| Preference for intervention | 52 (71.2) | 52 (69.3) | ||
| Preference for control | 1 (1.4) | 2 (2.7) | ||
| No preference | 20 (27.4) | 21 (28.0) | ||
| Treatment preference, parents | 152 | 152 | ||
| Preference for intervention | 118 (77.6) | 113 (74.3) | ||
| Preference for control | 1 (0.7) | 2 (1.3) | ||
| No preference | 27 (17.8) | 31 (20.4) | ||
| Missing | 6 (3.9) | 6 (3.9) |
Values are n (%) unless otherwise indicated. aThree children did not fulfil Rome criteria (reported 2–3 days of abdominal pain in past 2 months, required ≥4). bPrior paediatric consultations were permitted, but ongoing specialist care at baseline was an exclusion criterion. cRange treatment expectations: 0–10. AM = abdominal migraine. FAP = functional abdominal pain. FD = functional dyspepsia. IBS = irritable bowel syndrome. IQR = interquartile range. NRS = numerical rating scale.