# Validation of the IMPACT-III Questionnaire in French Children With Inflammatory Bowel Disease

Jérémy Vanhelst, Laurent Béghin, Elodie Drumez, Djamal Djeddi-Dine, Dominique Turck, Stéphanie Coopman, Frédéric Gottrand, Delphine Ley

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Jérémy Vanhelst, Laurent Béghin, Elodie Drumez, Djamal Djeddi-Dine, Dominique Turck, et al. Validation of the IMPACT-III Questionnaire in French Children With Inflammatory Bowel Disease. 2024. [hal-04693694](https://hal.science/hal-04693694v1)

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1 Validation of the IMPACT-III questionnaire in French children with inflammatory bowel

2 disease

3 Jérémy Vanhelst¹,², PhD, Laurent Béghin¹,², PhD, Elodie Drumez⁴,⁵, MsC, Djamal Djeddi⁶,

4 PhD, MD Dominique Turck¹,³, PhD, MD, Stéphanie Coopman³, MD, Frédéric Gottrand¹,³,

5 PhD, MD, Delphine Ley¹,³, PhD, MD

6

7 ¹ Univ. Lille, Inserm, CHU Lille, U1286 - INFINITE - Institute for Translational Research in

8 Inflammation, 59000, Lille, France.

9 ² Univ. Lille, Inserm, CHU Lille, CIC 1403 - Clinical Investigation Center, Lille, 59000,

10 Lille, France.

11 ³ CHU Lille, Division of Gastroenterology, Hepatology and Nutrition, Department of

12 Pediatrics, Lille University Jeanne de Flandre Children's Hospital, 59000, Lille, France.

13 ⁴ Univ. Lille, CHU Lille, ULR 2694 - METRICS: Evaluation des technologies de santé et des

14 pratiques médicales, 59000, Lille, France.

15 ⁵ CHU Lille, Department of Biostatistics, F-59000 Lille, France

16 ⁶ Department of Pediatrics, Amiens University Hospital and University of Amiens, Amiens,

17 France.

18

19 Corresponding author information:

20 J. Vanhelst

21 Antenne pédiatrique du CIC

22 Hôpital Jeanne de Flandre
23 CHU de Lille

24 Avenue Eugène Avinée

25 59000 Lille Cedex

26 Tel: +33 3 20 44 60 58

27 Fax: +33 3 20 44 66 87

28 E-mail: jeremy.vanhelst@hotmail.fr

29

30

31 Funding

32 This study received no funding support.

33

34 Competing interests

35 The authors declare no competing interests.

36

37 URL and CT number:

38 https://clinicaltrials.gov/ct2/show/NCT02341742?term=Turck+dominique&draw=2&rank=6

39 NCT02341742

40

41 Word count: 2669

42

43 Number of Tables: 5

44

45 Number of figure: 1 (as supplementary file)

46

47
48 Author contributions

All authors contributed significantly to the study. JV, LB, DL, FG, SC, and DT designed the research; JV, LB, and SC conducted the research; JV and ED analyzed the data; ED analyzed the data and performed the statistical analysis; JV, FG, and DT wrote the paper; JV had primary responsibility for the final content. All authors read and approved the final manuscript.

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56
1

# ABSTRACT

2

**Objectives:** This study assessed the reliability and validity of the IMPACT-III questionnaire, a health-related quality of life (HRQoL) instrument, in French children with inflammatory bowel disease (IBD).

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**Methods:** Eighty-four children and adolescents (45 boys, aged 14.3 ± 2.7 years) were included in a validation study of the IMPACT-III questionnaire. Patients completed two questionnaires for measuring HRQoL: the IMPACT-III and the Pediatric Quality of Life Inventory 4.0 Generic Core Scale (PedsQL™). Internal consistency was assessed using Cronbach's α. Factor analysis was performed on data from the IMPACT-III to help construct domains. Concurrent validity was assessed by calculating Spearman correlation coefficients.

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**Results:** Cronbach's α for the PedsQL™ total score was good (0.89). The most robust factor solution was a three-domain structure: a) Concerns, b) Body Image and Physical Condition, and c) Symptoms and Socializing. All domains had good reliability (0.674 to 0.863). Only two items had to be removed. Discriminant validity was demonstrated by significant differences (*p* < 0.001) in median IMPACT-III scores between inactive and active disease for the total score (83.3 vs. 72.0), and for Concerns (*p* < 0.002) and Symptoms and Socializing (*p* < 0.001).

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**Conclusions:** These results suggest that IMPACT-III appears to be a useful instrument for measuring HRQoL in French children with IBD.

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**Keywords:** Crohn disease; ulcerative colitis; pediatric; quality of life.

21
## 22 What is Known:

* IMPACT-III questionnaire is an important tool for assessing health-related quality of life (HRQoL) in pediatric patients with inflammatory bowel disease (IBD).

* Studies have examined the validity of this questionnaire for measuring HRQoL in European pediatric patients with IBD.

* No studies have examined the validity of this questionnaire in French children.

## 28 What is New:

* Our study is the first to assess the validity of this questionnaire in French children with IBD.

* IMPACT-III is a valid and reliable instrument for assessing HRQoL in French pediatric patients with IBD.

* Future studies in French children and adolescents with IBD should be able to use the IMPACT-III to assess the effects of intervention programs on quality of life.
## 35 Introduction

Inflammatory bowel diseases (IBD) encompass Crohn's disease (CD), ulcerative colitis (UC), and IBD-unclassified (IBD-U). These diseases are characterized by chronic inflammation of the gastrointestinal tract and represent a worldwide health-care problem. Several IBD symptoms, such as abdominal pain, diarrhea, and fatigue, as well as poor nutritional status and depression affect the quality of life in pediatric patients with IBD (1). In addition, regular visits to hospitals, constraints caused by treatment, disruption of schooling, complications of the disease, social and functional disability, and an uncertainty about the future may also compromise the quality of life of these children.

It is important to assess health-related quality of life (HRQoL) in pediatric patients with IBD to determine the consequences of these chronic diseases. HRQoL encompasses physical, mental, and social well-being. The Pediatric Quality of Life Inventory 4.0 Generic Core Scale (PedsQL™) is a widely used instrument to measure generic HRQoL in children and adolescents. The first instrument for assessing HRQoL in children with IBD was the IMPACT Questionnaire (IMPACT-I) (2-3). This questionnaire was developed after adaptation of the adult version of IBD disease-specific HRQoL questionnaire (2-4). This pediatric IBD-specific HRQoL instrument has since been modified by adding questions and changing the modality for answers, and is called the IMPACT-III questionnaire (5). Studies have examined the validity of this questionnaire for measuring HRQoL in pediatric patients with IBD (6-8). However, no studies have examined the validity of this questionnaire in French children.

The aim of this study was to assess the reliability and validity of the IMPACT-III questionnaire for measuring HRQoL in French children with IBD.
## 57 Materials and methods

### 58 *Study design*

The present study was an ancillary study of previous work assessing the associations between physical activity, bone health, and quality of life (9). Pediatric patients with IBD who were followed up in two hospitals in Northern France were invited to participate in this prospective study. Eighty-four children aged between 6 and 18 years with confirmed IBD at least 6 months before were included in this study from October 2014 to March 2017.

Before beginning the study, its aims and objectives were carefully explained to all participants and their parents/guardians. Written informed consent was obtained from the participant and consent from the parents/guardians by the study physician. The study was approved by the Research Ethical Committee (Comité de Protection des Personnes, Nord-Ouest IV, Lille, France) and French research competent authority (Agence Nationale de Sécurité du Médicament et des Produits de Santé, Paris, France). All procedures were performed according to the ethical standards of the 1975 Declaration of Helsinki as revised in 2013, and the European Union's Guidelines for Good Clinical Practice. According to the General Data Protection Regulation, data collection was approved by the French personal informatics competent authority (Commission Nationale de l'Informatique et des Libertés).

### 75 *Measurements*

#### 76 *Clinical assessment*

Each patient was required to pass a physical examination with a pediatric gastroenterologist (clinical investigator) before being included in the study. During the inclusion visit, anthropometric data (weight, height, and body mass index) were collected. Pubertal status was assessed by direct observation according to Tanner and Whitehouse (10).

A blood sample was collected from each patient and used for measurement of inflammatory
status (hematocrit, C-reactive protein and albumin concentrations, and erythrocyte sedimentation rate) and to calculate disease activity. Disease activity was assessed using a specific scale according to the type of IBD (11-12). The Pediatric CD Activity Index (PCDAI) was used for patients with CD (11). The Pediatric Ulcerative Colitis Activity Index (PUCAI) was used for patients with UC (12). Remission was defined as a score <10 and mild activity as 10-27.5 on the PCDAI and as 10-34 on the PUCAI. Values >27.5 on the PCDAI and >34 on the PUCAI indicated moderate to severe activity. **No IBD-U score was used as there is no validated scale available**

90

91 **HRQoL**

HRQoL was assessed by self-report using the PedsQL™ and the IBD-specific IMPACT-III questionnaire. Patients were asked to complete the two questionnaires during the same visit. A clinical investigator was present during the completion of questionnaires to help the children understand the questions if needed.

96

97 **PedsQL™**

The questionnaire is aimed at three age groups: 5-7 years, 8-12 years, and 13-18 years. For each age group, the questionnaire includes 23 questions comprising four dimensions: (i) physical functioning; (ii) emotional functioning; (iii) social functioning; and (iv) school functioning. The PedsQL™ provides a total score and two subscale dimensions: (i) physical health (physical functioning scale score) and (ii) psychosocial health (emotional, social, and school functioning scale scores). For children aged 8-18 years, each question was scored using a five-point Likert scale ranging from 0 (never) to 4 (almost/always). Appropriate items were reverse scored and total scores were linearly transformed to a 0-100 scale where 0 = 100, 1 = 105
75, 2 = 50, 3 = 25, and 4 = 0. For children aged 5–7 years, each question was scored using a three-point Likert scale of 0 (not at all), 2 (sometimes), and 4 (a lot).

108

## IMPACT-III Questionnaire

The IMPACT-III questionnaire comprises 35 closed questions about the frequency and intensity of the effects of IBD on various aspects of health. The questionnaire encompasses six specific domains: bowel symptoms (seven items), systemic symptoms (three items), emotional functioning (seven items), social functioning (12 items), body image (three items), and treatment/interventions (three items). The IMPACT-III uses a five-point Likert response scale ranging from 1 to 5 for all answers. The outcome score ranges from 35 to 175. To obtain a measure of overall HRQoL, a total score was calculated by summing all 35 items. A final open question allows patients to describe anything else they feel is important to their health. Because forward and backward translations were previously conducted, cross-cultural adaptation was not required (5). In the present paper, we studied the validity and reliability of this questionnaire.

121

## Statistical analysis

Qualitative variables are reported as frequency (percentage) and continuous variables as mean ± standard deviation in cases of normal distribution or median (interquartile range [IQR] = first quartile – third quartile) for nonnormal distribution. Normality was assessed graphically and using the Shapiro–Wilk test. Internal consistency was assessed using Cronbach's α, which was expected to be >0.70 (13).

Factor analysis was performed on data from the IMPACT-III to help construct domains. The number of components was checked by examination of the scree plot of eigenvalues using Horn's procedure and parallel analysis of 200 random simulations (14). Principal component
analysis was conducted for three-factor (domain) structures using varimax rotation. Items were
included in a domain when factor loadings (correlation between the item and the overall factor
or domain) was >0.3.

Concurrent validity was assessed by calculating Spearman correlation coefficients to assess
concurrence between domains of the PedsQL™ and IMPACT-III questionnaires. A strong
correlation was defined as r ≥ 0.5, a moderate correlation as r = 0.3-0.5, and a mild or weak
correlation as r < 0.3.

IMPACT-III scores were compared between different disease groups using the Kruskal–Wallis
test and between different disease activities using the Wilcoxon *U* test. All statistical tests were
performed at the two-tailed α level of 0.05 using SAS software (release 9.4; SAS Institute,
Cary, NC) and R 3.6.2 ('psy' packages).

142

143 **Results**

144 *Participants' characteristics*

For all patients, there were no missing answers for any items of both questionnaires. The
patients' demographic and disease characteristics are shown in Table 1. The sample (n=84)
included more boys (n = 45, 54%) and patients with CD (n = 37, 64%); 10 patients had IBD-U.
Most of the patients (77%) had inactive disease activity.

149

150 **Reliability**

The mean values and reliability coefficients for the total and original domains scores of the
IMPACT-III and PedsQL™ are shown in Table 2. The internal consistency (Cronbach's α) was
0.90 for the IMPACT-III total score. A good Cronbach's α was also found (0.89) for the
PedsQL™ total score.

155
156 **Factor structure of the IMPACT-III questionnaire domains**

157 A factor analysis was performed to explore the domains in the IMPACT-III questionnaire
158 (Table 3). The most statistically robust solution of the principal component analysis was a three-
159 factor structure, which was confirmed by the scree plot of eigenvalues (Suppl Figure 1). The
160 three domain titles chosen according to their Cronbach's α coefficients for each item are shown
161 in Table 3. The three domain titles chosen were a) Concerns (α = 0.863), b) Body Image and
162 Physical Condition (α = 0.840) and c) Symptoms and Socializing (α = 0.674) (Table 3).
163 Questions 31 ("How often did you have to pass wind in the last 2 weeks?") and 33 ("How do
164 you feel about your height?") were loaded into specific domains, but their factor loadings were
165 <0.3.
166

166

167 Concurrent validity

168 The results of the correlational analysis between the IMPACT-III and PedsQL™ scores are
169 presented in Table 4. Significant correlations were found in the cross-statistical analysis (*p* <
170 0.01). The strongest correlations were for the domains Concerns, Body Image and Physical
171 Condition, and Symptoms and Socializing emotional functioning (*r* = 0.58), physical health (*r*
172 = 0.49), and emotional functioning (*r* = 0.44) (Table 4). The domain Body Image and Physical
173 Condition correlated only moderately with social functioning (*r* = 0.33) in the PedsQL™. The
174 domain Body Image and Physical Condition also correlated only moderately with physical
175 health (*r* = 0.39) and school functioning (*r* = 0.25) in the PedsQL™.
176

176

177 Discriminant validity

178 The total and domain IMPACT-III scale scores in the overall population analyzed according to
179 the type of disease and disease activity are presented in Supplementary Table 1. These scores
180 did not differ significantly between disease type. The total score was higher in patients with
inactive disease (median 83.3 (IQR, 76.5 to 90.2); *n* = 62) than in those with active disease (median 72.0 (IQR, 60.6 to 82.6); *n* = 19) (*p* < 0.001). The IMPACT-III scores differed significantly between active and inactive disease for Concerns (*p* < 0.002) and for Symptoms and Socializing (*p* < 0.001) (Supp Table 1).

185

## Discussion

In addition to disease history and physical examination, use of HRQoL instruments may help give health-care providers a more comprehensive picture of the health status of a patient with IBD. IMPACT-III is a specific questionnaire for children with IBD that has been validated in many countries (Croatia, England, United States, Netherlands, Canada) (2,3,6,7,15,16). The results of our study show that the French version of IMPACT-III is suitable for assessing HRQoL in children and adolescents with inactive or mildly active IBD. The significant correlations between similar domains of the IMPACT-III (French version) and the PedsQL™ questionnaires confirm good concurrent validity of the French IMPACT-III questionnaire.

The factor analysis suggested that a three-factor structure was more appropriate for the French version of IMPACT-III and that two items seemed not be relevant in our model. Our results do not concur with previous studies that have assessed IMPACT-III in other countries, (i.e., in other languages) (2,3,6,7,8,15,16). However, the results of previous studies also do not agree with each other. A five-factor structure has been suggested by validations of British and Croatian versions of IMPACT-III, a four-factor structure by a study of young people in the United States and Switzerland, and a six-domain structure by studies of Dutch and Canadian versions (2,3,6,7,8,15,16). The differences reported for the three studies that assessed the Canadian and Dutch versions may be explained by differences in the methodologic approaches for assessing the domains (2,3,16).

The structures developed by previous authors were based on clinical relevance and judgmental
processes, whereas we used a statistical approach with factor analysis (2,3,16).

This difference in approach has also been mentioned by other authors who used factor analysis, which is more robust (6,7,8,15). Despite the similar use of factor analysis, it is difficult to compare our findings with those of the study of Perrin et al. (2008) in United States children and adolescents because of the different questionnaires used (15). The study by Perrin et al. analyzed the validity of an older version of the IMPACT questionnaire (Version II) which differs from the French version of IMPACT-III, which now includes a 10-cm visual analogue scale and more items (35 vs. 33 questions). Only studies using the Croatian, Swiss, and British versions used the same methodology as in our study (6-8). Differences between our results and those of these three studies may reflect differences in cultures between where the studies were performed.

Another possible explanation for differences between our results and those of earlier studies is the low statistical power in our study of 84 children compared with 104, 106, and 146 children for Croatian, British, and Swiss studies, respectively (6-8). The psychometric evaluation using Cronbach's α in our study showed good internal reliability for the three structural factors.

Therefore, we conclude that the three-factor structure of the French version of the IMPACT-III questionnaire seems to be appropriate for measuring HRQoL in French children and adolescents with IBD. However, further study is needed with larger samples to confirm our conclusions.

Disparities found in the number of domains between studies make it difficult to interpret the assessment of HRQoL in multicentric international studies.

Concurrent validity was tested in our study by comparing scores between the three-factor structure and the PedsQL™ results. The patients in our study with a low HRQoL score assessed using the PedsQL™ scale also had a low score on the French version of the IMPACT-III questionnaire ($r = 0.709$). Our results of the discriminant validity also showed that the IMPACT-III questionnaire may be affected by patients' health status (total score $p < 0.001$).
For example, patients with active disease had a lower total HRQoL score than patients with inactive disease (*p* < 0.001). These results have been reported in previous studies (2,6,7). In contrast to previous work, our study did not include patients with severe disease, and future studies with larger samples across the range of disease activity are needed to assess the overall discriminant validity. The discriminant validating testing also showed no significant difference according to the type of disease (CD vs UC and IBD-U). Patients with CD had a similar mean total HRQoL score as patients with UC or IBD-U. This suggests that the French version of the IMPACT-III can be used to assess QoL in patients with CD or UC.

Our study has some strengths and limitations. First, as suggested above, the recruitment of our study sample was limited by inclusion criteria linked to the main objective of this study and patients with a severe IBD activity were not included (9). There was an overrepresentation of pediatric patients with inactive or mild IBD and no representation of those with a moderate to severe disease. Therefore, our results may not apply generally to all young people with IBD.

Another limitation is the small sample size and the unequal representation of disease types (i.e., more CD than UC patients). However, the incidence rate is higher for CD than UC in French pediatric IBD patients (17), and we believe that our sample may reflect the population of pediatric IBD patients in France (73% and 27% for CD and UC patients, respectively). Third, no test-retest reliability was assessed because this was an ancillary study that was not designed to examine this parameter. The first strength of the study is the multicentric study design, which should have limited shared method bias. The second strength in the use of standardized and validated methods for assessing IBD activity and HRQoL (PedsQL™). A third strength is the excellent response rate (100%) for completion of the two HRQoL questionnaires because this was an ancillary study to a clinical intervention study. Finally, the robust statistical psychometric analysis is another strength of our study.
In summary, our findings suggest that the IMPACT-III is a valid and reliable instrument for assessing HRQoL in French pediatric patients with IBD. The development of the French version of this questionnaire seems to be useful for assessing the impact of IBD on the HRQoL of patients with CD or UC. Future studies in French in children and adolescents with IBD should be able to use the IMPACT-III to assess the effects of intervention programs on QoL.
261 Acknowledgements

262 The authors thank the participants for completing this study.

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264

265
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8. Werner H, Landolt MA, Buehr P, et al. Validation of the IMPACT-III quality of life questionnaire in Swiss children with inflammatory bowel disease. J Crohns Colitis 2014; 8: 641-8.

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<table><caption>**Table 1.** Patient demographic and disease characteristics.</caption><thead><tr><th></th><th>Overall (n=84)</th><th>CD (n=58)</th><th>UC (n=16)</th><th>IBD-U (n=10)</th></tr></thead><tbody><tr><td>Age (years)</td><td>14.3 ± 2.7</td><td>14.5 ± 2.6</td><td>13.6 ± 3.1</td><td>14.5 ± 2.5</td></tr><tr><td>Male</td><td>45 (53.6)</td><td>37 (63.8)</td><td>6 (37.5)</td><td>2 (20.0)</td></tr><tr><td>Disease duration (months)</td><td>34.3 (16.6 to 64.8)</td><td>29.0 (15.3 to 58.5)</td><td>47.2 (33.5 to 61.6)</td><td>50.9 (14.8 to 74.4)</td></tr><tr><td>Weight (kg)</td><td>50.3 ± 14.7</td><td>51.6 ± 14.2</td><td>45.1 ± 18.2</td><td>50.8 ± 10.2</td></tr><tr><td>Height (cm)</td><td>159.8 ± 14.6</td><td>161.4 ± 14.1</td><td>154.3 ± 17.9</td><td>159.5 ± 10.6</td></tr><tr><td>BMI</td><td>19.5 ± 3.4</td><td>19.8 ± 3.5</td><td>18.2 ± 3.6</td><td>19.9 ± 2.7</td></tr><tr><td>Disease activity</td><td></td><td></td><td></td><td></td></tr><tr><td>Inactive</td><td>59 (79.7)</td><td>49 (84.5)</td><td>10 (62.5)</td><td>-</td></tr><tr><td>Mild</td><td>14 (18.9)</td><td>9 (15.5)</td><td>5 (31.3)</td><td>-</td></tr><tr><td>Moderately-Severe</td><td>1 (1.4)</td><td>0</td><td>1 (6.2)</td><td>-</td></tr><tr><td>PUCAI</td><td>5.0 (2.5 to 15.0)</td><td>-</td><td>5.0 (0.0 to 10.0)</td><td>-</td></tr><tr><td>PCDAI</td><td>3.0 (0.0 to 6.5)</td><td>3.0 (0.0 to 5.0)</td><td>-</td><td>-</td></tr><tr><td>Corticosteroids</td><td>49 (58.3)</td><td>34 (58.6)</td><td>8 (50.0)</td><td>7 (70.0)</td></tr><tr><td>Anti-inflammatory</td><td>75 (89.3)</td><td>54 (93.1)</td><td>14 (87.5)</td><td>7 (70.0)</td></tr></tbody></table>

Values are presented as count (percentage), mean ± standard deviation or median (interquartile range).

CD, Crohn's disease; UC, Ulcerative colitis; IBD-unclassified, IBD-U
<table><caption>**Table 2.** Mean values and reliability coefficients for total and original domains scores of IMPACT-III and PedsQL™ (n=84).</caption><thead><tr><th>Scale</th><th>No. of items</th><th>Score range</th><th>Mean ± SD</th><th>Cronbach's alpha</th></tr></thead><tbody><tr><td>IMPACT-III total score</td><td>35</td><td>0-100</td><td>81.1 ± 13.5</td><td>0.896</td></tr><tr><td>Social functioning</td><td>12</td><td>0-100</td><td>70.3 ± 17.9</td><td>0.662</td></tr><tr><td>Emotional functioning</td><td>7</td><td>0-100</td><td>85.7 ± 9.8</td><td>0.839</td></tr><tr><td>Bowel symptoms</td><td>7</td><td>0-100</td><td>73.3 ± 19.6</td><td>0.644</td></tr><tr><td>Systemic symptoms</td><td>3</td><td>0-100</td><td>75.8 ± 20.3</td><td>0.786</td></tr><tr><td>Body image</td><td>3</td><td>0-100</td><td>68.5 ± 23.5</td><td>0.626</td></tr><tr><td>Treatment interventions</td><td>3</td><td>0-100</td><td>78.8 ± 11.6</td><td>0.652</td></tr><tr><td>PedsQL™ Total Score</td><td>23</td><td>0-100</td><td>81.6 ± 13.4</td><td>0.892</td></tr><tr><td>Physical health</td><td>8</td><td>0-100</td><td>84.3 ± 13.5</td><td>0.733</td></tr><tr><td>Psychosocial health</td><td>15</td><td>0-100</td><td>80.2 ± 15.0</td><td>0.866</td></tr><tr><td>Emotional functioning</td><td>5</td><td>0-100</td><td>76.6 ± 20.0</td><td>0.777</td></tr><tr><td>Social functioning</td><td>5</td><td>0-100</td><td>90.8 ± 15.3</td><td>0.837</td></tr><tr><td>School functioning</td><td>5</td><td>0-100</td><td>73.2 ± 19.4</td><td>0.735</td></tr></tbody></table>

SD = standard deviation
<table><caption>**Table 3.** Proposed factor structure for IMPACT-III (HR) with factors and item loading, indicating original domains for each question</caption><thead><tr><th rowspan="2">IMPACT-III item</th><th colspan="3">Rotated factor loadings</th><th rowspan="2">Original IMPACT-III domain</th></tr><tr><th>Factor 1</th><th>Factor 2</th><th>Factor 3</th></tr></thead><tbody><tr><td colspan="5"><strong>Factor 1: Concerns (14 items)</strong></td></tr><tr><td>5: How much does it bother you that you have an illness that doesn't just go away?</td><td><strong>0.775</strong></td><td>0.151</td><td>0.273</td><td>Emotional functioning</td></tr><tr><td>12: How often do you think it's unfair that you have IBD?</td><td><strong>0.710</strong></td><td>0.037</td><td>0.326</td><td>Emotional functioning</td></tr><tr><td>13: During the last 2 weeks, were you ever angry that you have IBD?</td><td><strong>0.672</strong></td><td>0.174</td><td>0.343</td><td>Emotional functioning</td></tr><tr><td>19: How often do you worry about stool containing blood?</td><td><strong>0.658</strong></td><td>-0.002</td><td>0.009</td><td>Bowel symptoms</td></tr><tr><td>11: How much do you worry about health problems that you might have in the future?</td><td><strong>0.629</strong></td><td>0.248</td><td>0.222</td><td>Emotional functioning</td></tr><tr><td>22: How do you feel about the tests you have to go through?</td><td><strong>0.596</strong></td><td>0.039</td><td>0.144</td><td>Treatment interventions</td></tr><tr><td>24: How often do you worry about having an operation?</td><td><strong>0.587</strong></td><td>0.336</td><td>-0.088</td><td>Treatment interventions</td></tr><tr><td>8: How has your IBD affected your family?</td><td><strong>0.536</strong></td><td>-0.047</td><td>0.224</td><td>Social functioning</td></tr><tr><td>4: How much have you been worrying about having a flare up (increase in symptoms) in the last 2 weeks?</td><td><strong>0.497</strong></td><td>0.366</td><td>0.143</td><td>Emotional functioning</td></tr><tr><td>2: Taking medicines or tablets bothers you?</td><td><strong>0.487</strong></td><td>0.146</td><td>0.107</td><td>Treatment interventions</td></tr><tr><td>20: Are you worried you cannot have a girlfriend or boyfriend because of your IBD?</td><td><strong>0.471</strong></td><td>0.092</td><td>-0.079</td><td>Social functioning</td></tr><tr><td>14: Do you think too many rules or restrictions are placed on you because of your IBD?</td><td><strong>0.447</strong></td><td>0.347</td><td>0.305</td><td>Social functioning</td></tr><tr><td>27: Does your IBD make it difficult to travel or go on holiday?</td><td><strong>0.436</strong></td><td>0.176</td><td>0.126</td><td>Social functioning</td></tr><tr><td>18: Is it harder to make friends because of your IBD?</td><td><strong>0.322</strong></td><td>0.039</td><td>-0.133</td><td>Social functioning</td></tr><tr><td colspan="5"><strong>Factor 2: Body image & physical condition (12 items)</strong></td></tr><tr><td>35: How often are you able to go to school?</td><td>0.110</td><td><strong>0.726</strong></td><td>0.028</td><td>Social functioning</td></tr><tr><td>17: Did you have fun during the last 2 weeks?</td><td>0.189</td><td><strong>0.692</strong></td><td>-0.092</td><td>Social functioning</td></tr><tr><td>32: How tired have you felt in the last 2 weeks?</td><td>0.019</td><td><strong>0.669</strong></td><td>0.195</td><td>Systemic symptoms</td></tr><tr><td>29: Are you happy with your life?</td><td>0.219</td><td><strong>0.602</strong></td><td>0.186</td><td>Emotional functioning</td></tr><tr><td>6: How much energy did you have during the last 2 weeks?</td><td>-0.040</td><td><strong>0.578</strong></td><td>0.496</td><td>Systemic symptoms</td></tr><tr><td>9: How often did you miss out certain things because of your IBD?</td><td>0.233</td><td><strong>0.578</strong></td><td>0.093</td><td>Social functioning</td></tr><tr><td>34: Despite your IBD can you take part in as much sport as you would like?</td><td>-0.020</td><td><strong>0.565</strong></td><td>0.242</td><td>Social functioning</td></tr><tr><td>28: How did you feel in the last two weeks?</td><td>0.046</td><td><strong>0.554</strong></td><td>0.551</td><td>Systemic symptoms</td></tr><tr><td>15: How do you feel about the way you look?</td><td>0.114</td><td><strong>0.540</strong></td><td>-0.332</td><td>Body image</td></tr></tbody></table>
<table><tbody><tr><td>3: Has your IBD prevented you from eating what you like in the last 2 weeks?</td><td>0.073</td><td><strong>0.503</strong></td><td>0.347</td><td>Bowel symptoms</td></tr><tr><td>30: Do you feel there is someone you can talk to about your IBD?</td><td>0.289</td><td><strong>0.499</strong></td><td>-0.378</td><td>Social functioning</td></tr><tr><td>7: How do you feel about your weight?</td><td>0.284</td><td><strong>0.479</strong></td><td>-0.084</td><td>Body image</td></tr><tr><td colspan="5">Factor 3: Symptoms & socializing (7 items)</td></tr><tr><td>16: Are you embarrassed because of your bowel condition?</td><td>0.359</td><td>0.042</td><td><strong>0.712</strong></td><td>Emotional functioning</td></tr><tr><td>1: How much has your stomach been hurting in the last 2 weeks?</td><td>0.054</td><td>0.204</td><td><strong>0.649</strong></td><td>Bowel symptoms</td></tr><tr><td>21: How often did you feel sick in the last 2 weeks?</td><td>0.105</td><td>0.423</td><td><strong>0.513</strong></td><td>Bowel symptoms</td></tr><tr><td>26: Do you try and hide your IBD?</td><td>0.051</td><td>-0.107</td><td><strong>0.478</strong></td><td>Social functioning</td></tr><tr><td>23: Do other children bully you or leave you out of things because of your IBD or its treatment?</td><td>0.161</td><td>0.058</td><td><strong>0.472</strong></td><td>Social functioning</td></tr><tr><td>25: How often are you afraid you may have an accident (not get to the toilet on time)?</td><td>0.413</td><td>0.283</td><td><strong>0.467</strong></td><td>Bowel symptoms</td></tr><tr><td>10: How often have you been bothered by diarrhea in the last 2 weeks?</td><td>0.194</td><td>0.276</td><td><strong>0.344</strong></td><td>Bowel symptoms</td></tr><tr><td colspan="5">Items that did not load well</td></tr><tr><td>31: How often did you have to pass wind in the last 2 weeks?</td><td>0.227</td><td>-0.039</td><td>0.282</td><td>Bowel symptoms</td></tr><tr><td>33: How do you feel about your height?</td><td>0.243</td><td>0.088</td><td>0.169</td><td>Body image</td></tr></tbody></table>

Bold indicates factors on which each item loaded.
<table><caption>**Table 4.** Correlation between the IMPACT-III scales and PedsQL™ (n=84)</caption><thead><tr><th></th><th colspan="5">PedsQL™</th></tr><tr><th></th><th>Physical health</th><th>Emotional functioning</th><th>Social functioning</th><th>School functioning</th><th>Total score</th></tr></thead><tbody><tr><td>IMPACT-III</td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>Factor 1: Concerns</td><td>0.492 ***</td><td>0.567 ***</td><td>0.438 ***</td><td>0.403 **</td><td>0.601 ***</td></tr><tr><td>Factor 2: Body image &amp; physical condition</td><td>0.487 ***</td><td>0.427 ***</td><td>0.333 **</td><td>0.491 ***</td><td>0.561 ***</td></tr><tr><td>Factor 3: Symptoms &amp; socializing</td><td>0.393 ***</td><td>0.440 ***</td><td>0.355 **</td><td>0.254 **</td><td>0.458 ***</td></tr><tr><td>Total score</td><td>0.599 ***</td><td>0.638 ***</td><td>0.497 ***</td><td>0.508 ***</td><td>0.709 ***</td></tr></tbody></table>

<footnote>*p ≤ 0.05, **p ≤ 0.01, ***p ≤ 0.0001</footnote>
<figure><img src="image_2.png" /><figcaption>**Suppl Figure 1.** Scree plot of eigenvalues from principal component analysis on 35 items through the IMPACT-III questionnaire (n=84).</figcaption></figure>

A scree plot displays the eigenvalues associated with each factor in descending order. Point line represents the plot of observed eigenvalues obtained from the 84 patients included in this study. Plain lines represent plots of eigenvalues obtained from 200 random samples (parallel analysis). Only factors with eigenvalues that are greater than simulated values are interpreted. Here, three eigenvalues are above simulated values.
<table><caption>**Suppl Table 1.** Total and domain IMPACT-III scale score in overall population, according to disease and according to disease's activity</caption><thead><tr><th>IMPACT-III</th><th>Subgroups</th><th>Median (interquartile range)</th><th>p-value</th></tr></thead><tbody><tr><td rowspan="3">Factor 1: Concerns</td><td>Overall</td><td>80.4 (66.1 to 90.2)</td><td></td></tr><tr><td>Disease</td><td></td><td>0.25</td></tr><tr><td>CD (n=58)</td><td>83.9 (69.2 to 91.1)</td><td></td></tr><tr><td rowspan="3">Factor 2: Body image &amp; physical condition</td><td>UC (n=16)</td><td>77.7 (57.4 to 92.9)</td><td></td></tr><tr><td>IBD-U (n=10)</td><td>73.2 (64.6 to 78.6)</td><td></td></tr><tr><td>Disease's activity</td><td></td><td>0.002</td></tr><tr><td rowspan="3">Factor 3: Symptoms &amp; socializing</td><td>Inactive (n=59)</td><td>83.9 (71.4 to 91.1)</td><td></td></tr><tr><td>Active (n=15)</td><td>64.6 (48.2 to 78.6)</td><td></td></tr><tr><td>Overall</td><td>83.3 (75.0 to 89.6)</td><td></td></tr><tr><td rowspan="3">Total score</td><td>Disease</td><td></td><td>0.43</td></tr><tr><td>Crohn (n=58)</td><td>83.3 (75.0 to 89.6)</td><td></td></tr><tr><td>UC (n=16)</td><td>84.4 (80.2 to 89.6)</td><td></td></tr><tr><td rowspan="3">Total score</td><td>IBD-U (n=10)</td><td>78.1 (70.8 to 83.3)</td><td></td></tr><tr><td>Disease's activity</td><td></td><td>0.11</td></tr><tr><td>Inactive (n=59)</td><td>83.3 (75.0 to 91.7)</td><td></td></tr><tr><td rowspan="3">Total score</td><td>Active (n=15)</td><td>79.2 (64.6 to 85.4)</td><td></td></tr><tr><td>Overall</td><td>89.3 (78.6 to 96.4)</td><td></td></tr><tr><td>Disease</td><td></td><td>0.67</td></tr><tr><td rowspan="3">Total score</td><td>Crohn (n=58)</td><td>89.3 (82.1 to 96.4)</td><td></td></tr><tr><td>UC (n=16)</td><td>85.7 (75.0 to 98.2)</td><td></td></tr><tr><td>IBD-U (n=10)</td><td>83.9 (75.0 to 93.9)</td><td></td></tr><tr><td rowspan="3">Total score</td><td>Disease's activity</td><td></td><td>&lt;0.001</td></tr><tr><td>Inactive (n=59)</td><td>91.1 (83.3 to 96.4)</td><td></td></tr><tr><td>Active (n=15)</td><td>78.6 (67.9 to 85.7)</td><td></td></tr><tr><td rowspan="3">Total score</td><td>Overall</td><td>83.0 (72.0 to 88.6)</td><td></td></tr><tr><td>Disease</td><td></td><td>0.44</td></tr><tr><td>Crohn (n=58)</td><td>83.3 (73.5 to 89.4)</td><td></td></tr><tr><td rowspan="3">Total score</td><td>UC (n=16)</td><td>83.7 (72.3 to 88.3)</td><td></td></tr><tr><td>IBD-U (n=10)</td><td>77.7 (71.1 to 84.1)</td><td></td></tr><tr><td>Disease's activity</td><td></td><td>&lt;0.001</td></tr><tr><td rowspan="3">Total score</td><td>Inactive (n=59)</td><td>83.3 (76.5 to 90.2)</td><td></td></tr><tr><td>Active (n=15)</td><td>72.0 (60.6 to 82.6)</td><td></td></tr></tbody></table>

CD, Crohn's disease; UC, Ulcerative colitis; IBD-unclassified, IBD-U