Health-related quality of life (HRQOL) and symptom-specific measurement have been increasingly acknowledged as essential health outcome measures in clinical trials and health services research and evaluation involving pediatric patients with functional gastrointestinal (GI) disorders and organic GI diseases (hereafter referred to as GI disorders) (1–7). The emerging paradigm shift toward patient-reported outcomes (PROs) in clinical trials has additionally provided the opportunity to emphasize the importance of pediatric patient self-report measurement as efficacy outcomes in clinical trials (8). Well-validated HRQOL and symptom-specific measures provide a common metric on which to compare interventions both within and across patient groups. As such, HRQOL and symptom-specific instruments represent important outcome measures for the evaluation of treatments targeting GI disorders.
HRQOL is a multidimensional construct, consisting at minimum of the physical, psychological (including emotional and cognitive), and social health dimensions delineated by the World Health Organization (8,9). Although several generic HRQOL instruments have been validated in pediatric patients with GI disorders, a multidimensional GI symptom-specific HRQOL instrument is essential for understanding the particular health issues most germane for pediatric patients with GI disorders from the patient's perspective. Additionally, a multidimensional GI symptom-specific HRQOL instrument would be expected to be more sensitive in measuring the effect of disease-modifying therapies and detecting change in health status over time within a population of children with GI disorders.
Pediatric patients with GI disorders have consistently demonstrated impaired generic HRQOL (1–7); however, to our knowledge, there is no pediatric multidimensional GI symptom-specific HRQOL instrument available that measures GI symptoms across different pediatric GI disorders from the patient and parent perspectives using patient self-report for ages 5 to 18 years and parent proxy report for ages 2 to 18 years. To address this gap in the literature, we used qualitative methods as recommended by the Food and Drug Administration (FDA) to establish content validity (8), with pediatric patients with various GI disorders and their parents to generate the GI symptom-specific domains and items for the new multidimensional Pediatric Quality of Life Inventory (PedsQL) Gastrointestinal Symptoms Module.
Qualitative methods, specifically focus groups/individual interviews and cognitive interviewing techniques, have emerged as the standard methodology for developing items and supporting content validity for new HRQOL instruments (10–13), and have served as the foundation for previous PedsQL Disease-Specific Modules and symptom-specific scales (14–22). These qualitative methods are consistent with present FDA guidelines on PROs instruments (8) and as such, help establish the content validity of newly developed disease-specific HRQOL items. These iterative steps include a comprehensive review of the literature, expert opinion, and the patient perspective derived from focus groups/individual interviews and cognitive interviews to develop the conceptual framework for relevant disease-specific domains, item generation guided by the conceptual framework, and the iterative process of revising the items and item content based on patient cognitive think aloud and debriefing techniques.
Given the lack of an empirically validated multidimensional GI symptom-specific HRQOL instrument in the extant literature that measures GI symptoms across different pediatric GI disorders from the patient and parent perspectives using patient self-report for ages 5 to 18 years and parent proxy report for ages 2 to 18 years, the objective of the present study was to describe the qualitative methods used in the item development and content validation phase for the new PedsQL Gastrointestinal Symptoms Module items.
Participants and Settings
Pediatric patients with physician-diagnosed GI disorders (chronic constipation, functional abdominal pain, irritable bowel syndrome, inflammatory bowel disease [Crohn disease, ulcerative colitis], gastroesophageal reflux disease) ages 5 to 18 years and parents of pediatric patients with GI disorders ages 2 to 18 years were recruited from pediatric GI clinics at the Children's Hospital at Scott and White Memorial Hospital and Clinic in Temple, Texas, and Primary Children's Medical Center in Salt Lake City, Utah. Patients were recruited as part of purposive sampling, that is, sampling was targeted (nonrandom) to ensure that all of the age groups and a spectrum of GI disorders were represented. A total of 98 participants (46 pediatric patients ages 5–18 with GI disorders and 52 parents of patients with GI disorders ages 2–18) participated in the focus groups/individual interviews and cognitive interviewing phases. The pediatric sample comprised 76.9% (40) white non-Hispanic, 15.4% (8) Hispanic, 5.8% (3) other race/ethnicity, and 1.9% (1) race/ethnicity not reported. Additional sociodemographics of participants across the 3 qualitative methods groups, including the percentage and numbers of specific GI disorders (chronic constipation, functional abdominal pain, irritable bowel syndrome, inflammatory bowel disease [Crohn disease, ulcerative colitis], gastroesophageal reflux disease) of the participants, are contained in Table 1. Written parental informed consent and child assent (when appropriate) were obtained. The research protocol was approved by the institutional review board at each participating institution.
A comprehensive literature review examining research in adult and pediatric patients with GI disorders for the 5 most recent years was conducted using PubMed and Google Scholar to generate domains of interest for the focus interviews and content for items. Six pediatric gastroenterologists from various geographic regions of the United States with extensive clinical experience in GI disorders provided expert opinion regarding the conceptual framework.
Items were generated and modified as needed during the literature review, expert opinion feedback, focus interviews, and cognitive interviewing phases. These items were designed to measure the domains/symptoms/problems identified as important by pediatric patients with GI disorders, their parents, and health care experts who treat these patients. The grammar and syntax of the new items were structurally equivalent to those in the existing PedsQL item bank. Instructions and response scales for the PedsQL Gastrointestinal Symptoms Module were created to be consistent with the instructions and response scales of the PedsQL 4.0 Generic Core Scales for ages 2 to 18 and the other PedsQL Disease-Specific Modules. The PedsQL 5-point Likert-type response scale has been used widely in published PedsQL studies (0 = never a problem, 1 = almost never a problem, 2 = sometimes a problem, 3 = often a problem, 4 = almost always a problem), and has also previously undergone extensive cognitive interviewing for a number of Pediatric Patient Reported Outcomes Measurement Information System scales and were found acceptable and understood by both pediatric patients and parents (23–26).
Focus interviews were conducted by 2 clinical research coordinators trained by the first author (J.W.V.). The individual and small-group focus interviews were audiotaped and transcribed. Detailed notes were also taken during each focus interview. The interviews were conducted in a private room in the clinic. Individual focus interviews rather than focus groups were mostly conducted given the difficulty in arranging for pediatric patients and parents from different families to meet together at the same time.
Appendix I (available online only at https://links.lww.com/MPG/A75) contains examples of the semistructured interview script for the individual focus interviews developed based on the GI disorders literature, past experience in conducting focus interviews, and expert panel input. The script used an open-ended question format to generate patient and parent experiences.
Parents and children ages 8 to 18 were interviewed separately. Children ages 5 to 7 were interviewed with their parents present. The focus interviews were conducted using a semistructured interview format to elicit themes from children and families that were relevant to GI disorders.
Content analysis of each focus interview was conducted after each focus interview was completed and analyzed for saturation of themes, that is, the point at which no new information or themes were identified. Focus interviews were stopped when saturation of themes was achieved. A final content analysis to determine overall themes was performed when all of the focus interviews were completed.
Cognitive Interviews: Think Aloud
Cognitive interviews were conducted in a separate cohort of patients and parents who were not participants in the focus interviews. Interviewers were 3 clinical research coordinators trained by the first author (J.W.V.). Cognitive interview—think-aloud techniques were used to elicit feedback from pediatric patients with GI disorders and parents of pediatric patients with GI disorders on the themes and items identified and their appropriateness for pediatric GI disorders. The think-aloud protocols asked the participants to say out loud everything that they were thinking as they read aloud each question, from the moment they read each question for the first time to the time that they gave their reply on the response scale. The objective of this phase was to determine whether patients and parents understood each item and to determine whether there were any items that were difficult to understand, confusing to answer, or upsetting to discuss. Wording changes were made at this point if indicated to further improve the understandability of individual items based on patient and parent feedback. Cognitive think aloud interviews were stopped when no additional changes were identified by patients and parents.
Participants were also asked to use a 5-point rating scale (1 = not at all important to 5 = very important) to determine the importance of each domain on the child's HRQOL. Examples of the semistructured interview for the cognitive interviews are contained in Appendix II (available online only at https://links.lww.com/MPG/A76).
Cognitive Interviews: Debriefing
Next, cognitive interviews using cognitive debriefing methodology were conducted in a separate cohort of patients and parents who were not participants in either the focus interviews or the cognitive interview–think-aloud cohort. Debriefing protocols require participants to complete the questionnaire independently followed by a set of interviewer-administered probes or questions to identify any difficulties in the questionnaire design. The newly configured paper-and-pencil and Web-based electronic mode of administration versions for the PedsQL Gastrointestinal Symptoms Module items were administered to a separate sample of pediatric patients and parents, with cognitive debriefing techniques used to determine as a final pretest the feasibility and usability of these 2 modes of administration. Patients and parents were asked to complete the instrument and then review each item and provide feedback on clarity of wording, relevance of content, and ease of use of the instrument. Both patients and parents separately completed the newly constructed scales under similar conditions to the subsequent planned field test. Cognitive debriefing interviews were stopped when no additional changes were identified by patients and parents.
Examples of the semistructured interview for the cognitive debriefing interviews are contained in Appendix III (available online only at https://links.lww.com/MPG/A77). Participants were given gift cards for participating in the individual focus interviews, cognitive think-aloud interviews, or cognitive debriefing sessions.
The PedsQL Family Information Form
A modified version of the PedsQL Family Information Form was completed by parents (27). The PedsQL Family Information Form contains demographic information including the child's date of birth, sex, and race/ethnicity.
From the literature review, patient and parent focus interviews, cognitive interviews, including think-aloud and debriefing protocols, and expert opinion from 6 pediatric gastroenterologists, upper and lower GI broad overarching domains were generated, with specific domains for each. Table 2 contains the specific domains and examples of final items generated from the iterative feedback process of pediatric patients, parents, and pediatric gastroenterologists.
A total of 13 pediatric patients ages 5 to 18 with GI disorders and 14 parents of pediatric patients ages 2 to 18 with GI disorders participated in the focus interviews (Table 1). These interviews contributed to the identification of numerous cross-cutting themes that are reflected in Table 2.
The children and parents identified the recurrent and unpredictable nature of GI symptoms, particularly pain and episodes of stooling urgency. Worry was a prominent theme, and children expressed how they worried that they would have bowel accidents at school and in the company of peers. Communication issues with others were also of concern. Although fatigue was mentioned by 2 participants, for example, feeling tired after straining hard to have a bowel movement in the bathroom, it was not a common enough theme to warrant a separate scale. The decision was made to use the 18-item PedsQL Multidimensional Fatigue Scale to capture this theme in subsequent investigations because this 3-dimensional scale has been widely validated in other pediatric chronic conditions, including pediatric GI (2).
Major themes were identified from the data as part of the content analysis. The themes identified were grouped into appropriate disease- and treatment-related areas after discussing and reaching consensus by the investigators on any differences in the common and relevant themes identified. Themes were grouped into upper (esophageal, stomach, small intestine) and lower (colonic) GI content areas/domains.
Cognitive Interviewing: Think Aloud
A total of 15 pediatric patients ages 5 to 18 with GI disorders and 20 parents of pediatric patients ages 2 to 18 with GI disorders participated in the think aloud interviews to determine the importance of the identified themes (Table 1). Minor revisions were made based on this feedback. For example, participants recommended that “I have to work hard to poop” be replaced with “I have to push hard to poop.” The revisions typically reflected this type of minor wording changes to make the items more age appropriate. The exception was the addition of 2 new items that measured blood in the stool and toilet paper. No themes were deleted that were identified in the focus interviews or literature review.
The PedsQL Gastrointestinal Symptoms Module items and scales were constructed from this feedback and input from pediatric gastroenterologists, resulting in 76 items and 11 scales (stomach pain, stomach upset, food and drink limits, trouble swallowing, heartburn and reflux, gas and bloating, constipation, diarrhea, worry, medicines, and communication) consistent with the format and time frame, instructions, and response choices used by the PedsQL 4.0 Generic Core Scales and Disease-Specific Modules.
Cognitive Interviews: Debriefing
Cognitive debriefing of the PedsQL Gastrointestinal Symptoms Module instrument was conducted with 18 pediatric patients ages 5 to 18 with GI disorders and 18 parents of pediatric patients ages 2 to 18 with GI disorders (Table 1) who had not previously participated in the focus interviews or cognitive interviewing–think-aloud protocol. Based on patient and parent feedback on the paper-and-pencil and Web-based electronic modes of administration, all of the items were deemed acceptable, with no further revisions indicated. After this pretesting, the instrument was finalized for the subsequent field test.
Final Empirically Derived Items and Scales
Eleven scales were derived from the qualitative methods, with item content saturation achieved at 76 items (ie, no further themes or content were identified) after the cognitive interviews. The 11 scales consisted of stomach pain and hurt (5 items), stomach upset (8 items), food and drink limits (6 items), trouble swallowing (3 items), heartburn and reflux (8 items), gas and bloating (7 items), constipation, (15 items), diarrhea (7 items), worry (8 items), medicine (4 items), and communication (5 items). Examples of the final empirically derived items are contained in Table 2.
The present study presents the iterative phases of item development and content validation for the new multidimensional PedsQL Gastrointestinal Symptoms Module designed specifically for pediatric patients with GI disorders. Pediatric patients with various pediatric GI disorders and their parents fully participated in the item-generation process, and were instrumental in developing items that reflect the patient perspective. Their input provided the essential content needed to generate the GI symptom-specific themes. We essentially achieved data saturation during the individual focus interviews with 13 pediatric patients and 14 parents, with only 1 additional theme identified during the cognitive interviewing phase (blood on toilet paper or stool). Prior qualitative research has demonstrated that data saturation can occur within the first 12 interviews, with basic elements for metathemes present as early as the first 6 interviews (28).
To address present standards required by the FDA and other regulatory bodies and the research community for documenting the process for item generation and supporting content validity, it is necessary to follow a rigorously designed set of standardized qualitative methods (8,10,11). Following the existing PedsQL Module Development Methodology (14–22) and present standards for instrument development (8,10,11), the conceptual framework, content validity, and 76 items were developed and integrated into 11 scales.
As anticipated, the 11 domains derived from the qualitative methods reflected the specific concerns of the various pediatric GI disorders patient groups who participated, including both upper GI and lower GI symptoms and the effect of GI symptoms on patient health and well-being. In addition to the specific GI symptoms, the patients clearly worried about the effect of their symptoms on daily living, including school activities and interactions with peers. It was apparent that these various GI symptoms have a significant effect on the day-to-day functioning of these pediatric patients from their perspective as well as that of their parents.
Themes such as the child worrying about being near the bathroom in case of stooling urgency episodes emphasized the perspectives of the patients and parents from their daily experiences. Traditional clinical indicators do not typically account for these daily effects on patient experiences.
Potential study limitations include the generation of items from only 2 sites at 2 different geographic areas of the United States; however, it should be noted that the pediatric gastroenterologists who provided feedback were from 4 different sites across the United States. Furthermore, we were not able to include all of the possible GI disorders (eg, celiac disease) and certain patient groups contained relatively small numbers of participants (eg, ulcerative colitis). It is possible that our themes and domains do not include all those that are relevant to this patient population given the complexity of the GI disorders studied and the vast age range studied. Additionally, we attempted to use focus group methodology but were required to also include individual focus interviews given the difficulty in arranging group participation of families. Nevertheless, content saturation was achieved through the focus interviews and cognitive interviews involving a relatively large sample of 98 participants, reflecting the daily experiences of these patients from their perspective and that of their parents.
We are presently conducting national multisite field testing of the newly developed items and scales as the next iterative phase of instrument development to determine the feasibility, reliability, validity, and factor structure of the PedsQL Gastrointestinal Symptoms Module. This quantitative phase is important to eliminate redundant items and to further understand the instrument factor structure, including whether items load on their hypothesized scales.
It is anticipated that once the quantitative analyses for the multidimensional PedsQL Gastrointestinal Symptoms Module scales are completed, individual scales subsequently will be used as stand-alone scales as indicated by the particular symptom profile for a particular pediatric GI disorder. This use of individual PedsQL Module scales takes precedence from other PedsQL Modules. For example, the PedsQL Asthma Symptoms Scale from the PedsQL 3.0 Asthma Module has been used as a stand-alone scale (29,30), as has the PedsQL Cognitive Functioning Scale from the PedsQL Multidimensional Fatigue Scale (31–33). We anticipate that the newly developed PedsQL Gastrointestinal Symptoms Module multidimensional scales, in combination with the PedsQL 4.0 Generic Core Scales (physical, emotional, social, and school functioning) (27), and when indicated the PedsQL Multidimensional Fatigue Scale (2), will provide a more fine-grained understanding of the health and well-being of children with different GI disorders, and will be a valuable contribution to the empirical literature in measuring the changes in health status over time in these pediatric patients, as well as providing insight into new areas for future interventions for this pediatric population.
1. Varni JW, Lane M, Burwinkle T, et al. Health-related quality of life
in pediatric patients with irritable bowel syndrome: a comparative analysis. J Dev Beh Pediatr
2. Marcus SB, Strople JA, Neighbors K, et al. Fatigue and health-related quality of life
in pediatric inflammatory bowel disease. Clin Gastroenterol Hepatol
3. Youssef NN, Langseder AL, Verga BJ, et al. Chronic childhood constipation is associated with impaired quality of life: a case-controlled study. J Pediatr Gastroenterol Nutr
4. Youssef NN, Murphy TG, Langseder AL, et al. Quality of life for children with functional abdominal pain: a comparison study of patients’ and parents’ perceptions. Pediatrics
5. Youssef NN, Rosh JR, Loughran M, et al. Treatment of functional abdominal pain in childhood with cognitive behavioral strategies. J Pediatr Gastroenterol Nutr
6. Clarke MCC, Chow CS, Chase JW, et al. Quality of life in children with slow transit constipation. J Pediatr Surg
7. Marlais M, Fishman JR, Koglmeier J, et al. Quality of life in children with gastro-oesophageal reflux disease. Acta Paediatr
8. Guidance for Industry: Patient-reported Outcome Measures: Use in Medical Product Development to Support Labeling Claims
. Rockville, MD: Food and Drug Administration, US Department of Health and Human Services; 2009.
9. Constitution of the World Health Organization: Basic Document
. Geneva, Switzerland: World Health Organization; 1948.
10. Lasch KE, Marquis P, Vigneux M, et al. PRO development: rigorous qualitative research as the crucial foundation. Qual Life Res
11. Brod M, Tesler LE, Christensen TL. Qualitative research and content validity: developing best practices based on science and experience. Qual Life Res
12. Walsh TR, Irwin DE, Meier A, et al. The use of focus groups in the development of the PROMIS pediatrics item bank. Qual Life Res
13. Irwin DE, Varni JW, Yeatts K, et al. Cognitive interviewing methodology in the development of a pediatric item bank: a patient reported outcomes measurement information system (PROMIS) study. Health Qual Life Outcomes
14. Varni JW, Burwinkle TM, Berrin SJ, et al. The PedsQL
in pediatric cerebral palsy: reliability, validity, and sensitivity of the Generic Core Scales and Cerebral Palsy Module. Dev Med Child Neurol
15. Varni JW, Burwinkle TM, Jacobs JR, et al. The PedsQL
in type 1 and type 2 diabetes: reliability and validity of the Pediatric Quality of Life Inventory Generic Core Scales and Type 1 Diabetes Module. Diabetes Care
16. Varni JW, Burwinkle TM, Katz ER, et al. The PedsQL
in pediatric cancer: reliability and validity of the Pediatric Quality of Life Inventory Generic Core Scales, Multidimensional Fatigue Scale, and Cancer Module. Cancer
17. Varni JW, Burwinkle TM, Rapoff MA, et al. The PedsQL
in pediatric asthma: reliability and validity of the Pediatric Quality of Life Inventory Generic Core Scales and Asthma Module. J Beh Med
18. Varni JW, Seid M, Knight TS, et al. The PedsQL
in pediatric rheumatology: reliability, validity, and responsiveness of the Pediatric Quality of Life Inventory Generic Core Scales and Rheumatology Module. Arthritis Rheum
19. Goldstein SL, Graham N, Warady BA, et al. Measuring health-related quality of life
in children with ESRD: performance of the Generic and ESRD-Specific Instrument of the Pediatric Quality of Life Inventory (PedsQL
). Am J Kidney Dis
20. Palmer SN, Meeske KA, Katz ER, et al. The PedsQL
Brain Tumor Module: Initial reliability and validity. Pediatr Blood Cancer
21. Weissberg-Benchell J, Zielinski TE, Rodgers S, et al. Pediatric health-related quality of life
: feasibility, reliability and validity of the PedsQL
Transplant Module. Am J Transplant
22. Varni JW, Limbers CA, Neighbors K, et al. The PedsQL
Infant Scales: feasibility, internal consistency reliability and validity in healthy and ill infants. Qual Life Res
23. Irwin DE, Stucky BD, Thissen D, et al. Sampling plan and patient characteristics of the PROMIS pediatrics large-scale survey. Qual Life Res
24. Varni JW, Stucky BD, Thissen D, et al. PROMIS Pediatric Pain Interference Scale: an item response theory analysis of the pediatric pain item bank. J Pain
25. Irwin DE, Stucky BD, Langer MM, et al. An item response analysis of the pediatric PROMIS anxiety and depressive symptoms scales. Qual Life Res
26. Yeatts K, Stucky BD, Thissen D, et al. Construction of the Pediatric Asthma Impact Scale (PAIS) for the Patient-Reported Outcomes
Measurement Information System (PROMIS). J Asthma
27. Varni JW, Seid M, Kurtin PS. PedsQL
4.0: reliability and validity of the Pediatric Quality of Life Inventory Version 4.0 Generic Core Scales in healthy and patient populations. Med Care
28. Guest G, Bunce A, Johnson L. How many interviews are enough? An experiment with data saturation and variability. Field Methods
29. Chan KS, Mangione-Smith R, Burwinkle TM, et al. The PedsQL
: reliability and validity of the Short-Form Generic Core Scales and Asthma Module. Med Care
30. Seid M, Limbers CA, Driscoll KA, et al. Reliability, validity, and responsiveness of the Pediatric Quality of Life Inventory (PedsQL
) Generic Core Scales and Asthma Symptoms Scale in vulnerable children with asthma. J Asthma
31. McCarthy ML, MacKenzie EJ, Durbin DR, et al. The Pediatric Quality of Life Inventory: an evaluation of its reliability and validity for children with traumatic brain injury. Arch Phys Med Rehabil
32. Varni JW, Limbers CA, Sorensen LG, et al. PedsQL
Cognitive Functioning Scale in pediatric liver transplant recipients: Feasibility, reliability and validity. Qual Life Res
33. Limbers CA, Heffer RW, Varni JW. Health-related quality of life
and cognitive functioning from the perspective of parents of school-aged children with Asperger's syndrome utilizing the PedsQL
. J Autism Dev Dis