A Narrative Review of Patient-Reported Outcome Measures and Their Application in Recent Pediatric Surgical Research: Advancing Knowledge and Offering New Perspectives to the Field

Introduction  Patient-reported outcome measures (PROMs) can be employed in both research and clinical care to enhance our understanding of outcomes that matter to patients. This narrative review aims to describe PROM use in recent pediatric surgical research, identify and describe psychometrically robust PROMs, providing an overview of those derived from pediatric patient input, and make recommendations for future research. Materials and Methods  A search was conducted to identify articles published from 2021 to August 2023 describing the availability and/or use of at least one valid or reliable PROM in children with conditions including anorectal malformations, biliary atresia, congenital diaphragmatic hernia, duodenal atresia, esophageal atresia, abdominal wall defects, Hirschsprung's disease, sacrococcygeal teratoma, and short bowel syndrome. Articles were categorized based on their objectives in applying PROMs. Psychometrically robust PROMs were identified and described. Results  Out of the 345 articles identified, 49 met the inclusion criteria. Seventeen focused on esophageal atresia and 14 on Hirschsprung's disease. Twenty-nine PROMs were identified, with 12 deemed psychometrically robust. Seven psychometrically robust PROMs were developed using patient input in the primary item generation. Most PROMs were applied to advance understanding of conditions and/or treatment and fewer were developed or psychometrically evaluated. No PROMs were assessed for their impact or incorporated into an implementation study. Conclusions  This review reveals gaps in the application of PROMs in recent pediatric surgical research. Emphasis should be placed on the development and utilization of psychometrically robust PROMs, broadening the scope of covered diseases, conducting impact assessments, and evaluating implementation strategies.


Introduction
Pediatric surgeons treat children with a variety of low-prevalence and complex congenital conditions.These conditions encompass anomalies involving the esophagus and/or respiratory organs (congenital diaphragmatic hernia, esophageal atresia), bile ducts (as seen in biliary atresia), and the abdomen and bowel/intestine (encompassing anorectal malformations, duodenal atresia, gastroschisis, omphalocele, Hirschsprung's disease, and short bowel syndrome). 1Children born with these congenital conditions often require surgery to ensure their survival and need inpatient post-surgical care.
Over the past few decades, medical and surgical advances have led to an increased survival rate for children with these conditions.3][4][5] However, as mortality rates have declined, there is an increasing recognition of the long-term somatic and psychosocial challenges.These challenges encompass both condition-specific morbidities and the impact of longterm medical care, which may involve numerous and sometimes long-term hospitalizations, repeated invasive medical assessments, and anesthesia. 6[9][10][11] In the field of pediatric surgery, the utilization of PROMs, 11 including those measuring multidimensional concepts like health-related quality of life (HRQoL), 1,[7][8][9][10] has seen an increase in recent years.In their recent systematic review, Besner et al 11 provide an overview of frequently used, valid PROMs employed to assess components of HRQoL in pediatric surgical research from 1996 to May 2021.In addition to validity, a key psychometric property that can be used to judge the quality of a PROM and the information it collects is reliability. 12Incorporating direct patient input into the primary item generation phase of PROM development is also recommended as a current standard, 13 to ensure the instrument is comprehensive and measures aspects of importance to the target population.As the field of PROMs in pediatric surgery is growing, it is also important to review PROM development and validation studies, which has not yet been done.
This narrative review therefore aims to further advance our knowledge of available PROMs in pediatric surgery, by describing recent studies in the field, identifying and describing psychometrically robust (valid and reliable) PROMs, and providing an overview of those derived from pediatric patient input.In doing so, this review offers new perspectives and essential recommendations to advance PROM research in pediatric surgery and facilitate successful and effective utilization.

Methods Definitions and Purpose
A patient-reported outcome is information about a patient's health directly provided by the patient, including details about symptoms, health status, quality of life, and the impact of disease and treatment on physical, social, and psychological well-being, known as HRQoL. 13The tool used to gather this information from patients is called a PROM. 13ROMs can be categorized as generic or condition-specific, depending on whether they are designed for broader use or tailored to a specific population and clinical context.5][16][17] In cases where pediatric patients are unable to provide their own reports, caregivers can complete PROMs on their behalf, known as proxy-reports, which provide valuable information about a child's health. 14,18PROMs help to ensure that care, research, and policymaking remain patient-centered. 15,19To be considered suitable for use, PROMs must exhibit psychometric robustness, including validity and reliability. 12In clinical practice, there is growing evidence that the use of pediatric PROMs positively impacts patient outcomes, health processes, and health services, [20][21][22] which is particularly valuable in pediatric surgery due to the risk of long-term and complex morbidity.Implementing PROMs in clinical practice necessitates overcoming methodological challenges, 23 ethical considerations, 24 and potential barriers. 22,24ffective strategies exist to overcome potential barriers. 22

Study Design and Search Strategy
We conducted a narrative review to identify studies describing the availability and use of PROMs for children undergoing pediatric surgery.This review adhered to the six predefined criteria aimed at enhancing the quality of narrative reviews, as outlined by Baethge et al. 25 This includes providing an explanation of the article's importance, defining and describing the aims of the review and the literature search, Most PROMs were applied to advance understanding of conditions and/or treatment and fewer were developed or psychometrically evaluated.No PROMs were assessed for their impact or incorporated into an implementation study.Conclusions This review reveals gaps in the application of PROMs in recent pediatric surgical research.Emphasis should be placed on the development and utilization of psychometrically robust PROMs, broadening the scope of covered diseases, conducting impact assessments, and evaluating implementation strategies.
referencing, and presenting appropriate evidence and relevant endpoint data.
A comprehensive search was conducted in the following databases with the assistance of a medical librarian (W.M.B.): Medline (Ovid), CINAHL (EBSCOHost), Embase (embase.com),Web of Science Core Collection, and the Cochrane Central register of Controlled Trials (Wiley).The search strings used in each of the databases are included in ►Supplementary Material S1.The search terms were based on previous studies 11,20 and input from four authors in the field of pediatric surgery (J.D., M.D.B., O.K.C.S., A.R.).The initial search had no restrictions on publication dates.However, to extend and advance the systematic review by Besner et al 11 with the latest literature, the identified articles were subsequently filtered to include only those published from January 2021 to August 8, 2023.

Article Selection
►Table 1 presents the inclusion and exclusion criteria for article selection.To identify articles that qualified for inclusion, one researcher (O.K.C.S.) screened the titles, abstracts, and full texts (as necessary) of the publications yielded by the initial search and screened the full texts of all eligible articles.Any uncertainties regarding inclusion or exclusion were discussed with two additional researchers (M.D.B., J.D.).
Articles were included if they employed at least one valid or reliable PROM 26 and assessed aspects of physical, mental, social, or multidimensional concepts, including HRQoL, in children aged 18 years or younger with conditions including anorectal malformations, biliary atresia, congenital diaphragmatic hernia, duodenal atresia, esophageal atresia, abdominal wall defects (omphalocele, gastroschisis), Hirschsprung's disease, sacrococcygeal teratoma, and short bowel syndrome.The PROM results needed to be sufficiently analyzed and clearly reported for at least one of these patient populations.Studies assessing patients' health status using single yes/no response questions were not regarded as employing a valid or reliable PROM and were therefore excluded.
For a PROM to be deemed "valid," a validation process needed to have been carried out in a pediatric population

Inclusion criteria
Full-text publication in English language
Seventeen studies employed PROMs that were self-developed, developed for other conditions than applied and/or originally developed for adults.Five of these studies employed PROMs that were self-developed.Four studies employed PROMs that were developed for other conditions than applied, including the Vancouver Symptom Score, 79 the BCS, 78 when applied in Hirschsprung's disease and sacrococcygeal teratoma patient populations, and the Lower Urinary Tract Symptoms (LUTS) Questionnaire 80 (see ►Table 2).Nine studies employed PROMs originally developed for adults (n ¼ 5), including the Gastrointestinal Quality of Life Index (GIQLI), 92 Cleveland Clinic Fecal Incontinence Severity Scoring System (or Wexner score), 81,82 Reflux Disease Questionnaire (RDQ), 93 Danish Prostatic Symptom Score (DAN-PSS), 99 and the Early Pediatric Groningen Defecation and Fecal Continence Questionnaire (EP-DeFeC). 101Mental health assessments were conducted using the Strengths and Difficulties Questionnaire (SDQ) 94 in studies focusing on esophageal atresia (n ¼ 4) and on more than one condition (n ¼ 2).►Fig. 2 presents the number of articles employing the identified PROMs, categorized per condition.
Out of the 29 PROMs identified, most (n ¼ 28) were applied in observational studies (n ¼ 47), while only two studies employed an experimental, randomized trial design. 34,60The majority of articles employed PROMs to enhance understanding of the respective medical conditions and treatment strategies under investigation (n ¼ 44).One study was dedicated to the development of a specific PROM, known as the Diet and Bowel Questionnaire. 66Four studies focused on the psychometric evaluation of one condition-specific PROM (Esophageal-Atresia-Quality-of-life Questionnaires, EA-QOL) across four countries. 37,47,49,50None of the PROMs were subjected to an evaluation of their impact on patient, process, and/or health service-related outcomes.However, three PROMs were applied, in two studies, 74,75 to assess the relationship between the PROM of interest and other outcome measures, aiming to determine its added value in follow-up care.No PROM was applied as part of an implementation study.
►Table 3 lists the 12 PROMs that were deemed psychometrically robust.These PROMs were found to demonstrate both validity and reliability in their pediatric target population, while remaining aligned with the instrument's original conceptual aim.Six of these psychometrically sound PROMs were generic HRQoL questionnaires, 83,85,87-90,95,100 two were condition-specific HRQoL questionnaires for children born with esophageal atresia (EA-QOL) 91 or Hirschsprung's disease and anorectal malformations (Hirschsprung's disease Anorectal malformation Quality of Life Questionnaire, HAQL), 103 and four were symptom-specific or domain-specific, targeting mental health (SDQ), 94

Discussion
This narrative review, which had the objective of advancing our knowledge of available PROMs in pediatric surgery, illustrates the ongoing growth in the utilization of PROMs in pediatric surgical research.Our findings, which largely mirror those reported by Besner et al, 11 underscore the gaps in the availability of PROM research for certain pediatric surgical conditions, including anorectal malformations, biliary atresia, congenital diaphragmatic hernia, duodenal atresia, abdominal wall defects, sacrococcygeal teratoma, and short bowel syndrome.

PROM Development and Suitability for Use
In the article selection and review process, we observed that a notable number of studies utilized self-developed questionnaires, adult PROMs, and in some cases, PROMs originally developed for other conditions.While the use of in-house and other non-psychometrically robust PROMs may indicate good intentions and initial efforts, it is important to note that among the 29 PROMs identified by this narrative review, only 12 can be recommended as measures demonstrating adequate validity and reliability for use in pediatric populations.Among these, only two are condition-specific.The U.S. Food and Drug Administration guidelines published in 2009 13 have had a           There is ongoing debate about whether future development efforts should prioritize condition-specific PROMs.However, considering shared symptomology across different conditions, there may be advantages in utilizing symptomor domain-specific measurement approaches. 103In this narrative review, we observed that psychometrically robust symptom-or domain-specific questionnaires were tailored to specific health conditions, encompassing gastrointestinal symptoms, cognitive functioning, and mental health.Notably, a single PROM has been developed to measure HRQoL for two conditions, anorectal malformation and Hirschsprung's disease. 103However, condition-specific PROMs can be essential for identifying symptom-related challenges which are significant for people living with a particular medical condition. 16Qualitative interviews and focus groups involving pediatric patients and their parents can be instrumental in enhancing our understanding of these condition-specific experiences. 14,106,107he evaluation of postoperative colorectal functional outcomes, including aspects like continence, was conducted by the Rintala Bowel Function, 77 Baylor Continence, 78 Cleveland Clinic Fecal Incontinence Severity (or Wexner), 81,82 or Krickenbeck 102 scoring models.These models assess conditionspecific outcomes important for patients with anorectal malformations and Hirschsprung's disease. 103,109,110The Rintala Bowel Function and Krickenbeck postoperative assessment instruments generate clinical scores through the use of questionnaires.The frequent application of these scoring models in research, providing a standardized approach to outcome assessment, is undeniably advantageous.However, these instruments may not meet the criteria for international PROM standards, as a PROM should be completed by the patient "without interpretation by a clinician or someone else." 13 Additionally, these models lack input from patients and parents during their development.Similarly, the BCS was validated for children with anorectal malformations 78 but was not developed with direct patient input.Neither the Rintala Bowel Function and Krickenbeck scoring models nor the BCS seems to have undergone comprehensive evaluations based on established psychometric criteria of feasibility, validity, and reliability. 26

Translation and Cross-Cultural Validation
In order to maximize opportunities for rare disease research and quality improvement initiatives facilitated through international collaboration, the translation of PROMs into multiple languages is needed. 111Generic HRQoL instruments such as the KIDSCREEN, 95 PedsQL 4.0, 83 and KINDL-R 100 are translated in multiple languages.However, the availability of translated condition-specific and symptom-or domain-specific questionnaires varies widely.Previous research has pointed out the necessity to reduce heterogeneity in outcome assessment and promote standardization of PROMs, such as for anorectal malformations, 112 biliary atresia, 7 Hirschsprung's disease, 112 and esophageal atresia, 113 by translating and psychometrically evaluating existing PROMs and developing new PROMs as needed.Just recently, a study reporting on the translation and cultural adaptation of the EA-QOL questionnaire for use in 14 countries was published. 114Such initiatives can be used as a model for other PROMs in pediatric surgery to standardize outcome assessments cross-culturally.Sets of internationally agreed measures may be of great value in achieving standardized outcome measurement.However, measures included should demonstrate psychometric robustness and meet international PROM standards.

Impact Assessment and Implementation
Most of the identified PROMs were not applied in studies with a randomized trial design, perhaps due to conceptual and methodological challenges related to the use of PROMs in clinical trials with low-prevalence, heterogeneous conditions. 115Studies with rigorous study designs, including randomized controlled trial (RCTs), have been advocated for the comprehensive assessment of the impact of PROM use in pediatric clinical care on various critical outcomes. 20,21The measurement of patient-reported outcomes can aid in assessing the effectiveness of a treatment or the longitudinal monitoring of health status, 116 thereby supporting clinical decisionmaking.By assessing the relationship between PROMs and other clinical outcome measures, two studies confirmed the complementary value of PROMs for clinical decision-making.However, none of the PROMs were subjected to an evaluation of their impact on patient, process, and/or health servicerelated outcomes.This observation aligns with findings of previous studies 20,21 reporting on more common pediatric health conditions such as diabetes, asthma, idiopathic arthritis, and cancer.None of the identified PROMs were applied in an implementation study.This identifies impact assessment and implementation as key areas for future focus in the field of PROM research in pediatric surgery.
The field of implementation science offers a structured way of supporting the adoption and evaluation of PROM use in clinical practice. 117,118Implementation science entails the examination of methods used to facilitate the adoption of evidence-based practices.It draws on theoretical approaches to describe implementation processes, understand and explain factors influencing implementation, and assess the success and effectiveness of implementation strategies. 119ntil recently, it was little known how to effectively implement PROMs in pediatric settings.Scott et al, 22 however, present a list of effective strategies derived from a recent systematic review, based on recognized barriers and facilitators ("determinants").Barriers included a lack of evidence justifying the psychometric properties of a PROM and a lack of crosscultural validity and availability of translated versions.There may also be context-specific determinants at play, which can inform the development of context-specific implementation strategies.
The absence of implementation studies, as found in our review and by Besner et al, 11 aligns with Scott et al, 22 who also report no identified implementation studies in the field of pediatric surgery.Application of implementation science principles has gained recognition in pediatric surgery, offering added value. 120The use of valid and reliable HRQoL questionnaires in the follow-up care of patients with esophageal atresia has been recommended by the European Reference Network for rare Inherited and Congenital Anomalies (ERNICA) and the International Network for Esophageal Atresia (INoEA). 121,122However, it is important to acknowledge that many HRQoL measures were not primarily designed for individual clinical decision-making, so PROMs should complement clinical data. 15omprehensive evaluations of PROM usage in clinical practice, with or without implementation strategies, help determine whether observed changes result from PROM utilization or other factors, such as patient-provider discussions.To enhance understanding, exploring the mechanisms behind outcomes is crucial.For example, increased office visits and endoscopies post-PROM usage may indicate heightened disease awareness or greater willingness to seek care. 123Health care professionals' understanding of PROM content is also vital for accurate interpretation of changes. 15

Considerations, Strengths, and Limitations of the Study
While our review adhered to predefined quality criteria, it is not a systematic review and lacks full comprehensiveness.A strength of this review is its broad focus, allowing for the identification of studies pertinent to all stages of the PROM development and application process.In addition to validity, reliability was also considered in determining a PROM's psychometric robustness and the use of patient input in the primary item generation phase was reviewed.Our review does not attempt to provide a full overview of available PROMs recommended for use in pediatric surgery.Rather, it offers new perspectives on PROM research for pediatric surgical conditions, by incorporating lessons from the field of psychometrics.Detailed psychometric evaluations were, however, beyond the article's scope.For example, a PROM's ability to detect change over time (its "responsiveness") was not assessed.Like Besner et al, 11 we applied the Wilson and Cleary model 27 to classify the PROM content.However, there is potential domain overlap.The review focused solely on children, leaving room for further research on the use of PROMs in adult patients and on outcomes that matter to parents.

Conclusions and Recommendations to Advance the Field of PROM Research and Promote Successful and Effective Use
While this review demonstrates an increased utilization of PROMs in recent years in pediatric surgical research, this increase seems to be predominantly confined to specific conditions, particularly esophageal atresia and Hirschsprung's disease.Our review underscores the need to broaden the scope of PROM research to include anorectal malformations, biliary atresia, congenital diaphragmatic hernia, duodenal atresia, abdominal wall defects, sacrococcygeal teratoma, and short bowel syndrome.
Our review identified PROMs that are both psychometrically robust and derived from initial pediatric patient input.In future research, valid and reliable PROMs for children and adolescents should be used, and not those developed for adults.Furthermore, their recommended use in research and clinical practice and the need for future PROM development studies will depend on the patient population under investigation and the maturity of the field.This includes the "maturity" of the PROM itself, which can be determined by using the ideal process for PROM development and standardized use described in ►Supplementary Material S2.
The need for new instruments and/or the suitability of those existing should be evaluated, considering factors such as condition-specific morbidity and the views and experiences of patients.For some conditions, such as abdominal wall defects, a systematic review of HRQoL in affected children is lacking and therefore warranted.Existing condition-specific PROMs, such as the HAQL and EA-QOL, are recommended for use, translation, and cultural adaptation to standardize outcome assessment and increase the generalizability of study findings.However, a psychometrically robust PROM developed with patient input is warranted to assess colorectal function in rare and complex malformations.For all conditions investigated in this study, the longitudinal assessment of HRQoL is required.
Furthermore, patients with several pediatric surgical conditions could benefit from using existing symptom-specific PROMs, such as the PedsQL GI Module, following appropriate translation and cross-cultural psychometric evaluation.As symptom-or condition-specific PROMs are likely to demonstrate increased sensitivity to disease severity, the PedsQL GI Module, EA-QOL, and HAQL, among others, could be used to incorporate the patient perspective into clinical treatment evaluations.
Altogether, to ensure high-quality data collection from patients, our findings emphasize the importance of applying PROMs appropriately and developing psychometrically robust instruments that are translated and cross-culturally validated.However, we also recommend a future review to provide comprehensive guidance to researchers and clinicians on how to select and use PROMs appropriately for the pediatric surgical conditions investigated.
To explore PROM impact on patient, process and health service-related outcomes, rigorous study designs, such as RCTs, are recommended.Evaluating PROM use can reveal whether changes result from the PROM itself or other factors.The successful and effective implementation of PROMs is also highlighted as a key future research topic in pediatric surgery.Multicenter and international collaboration is vital for PROM development, psychometric evaluation, and implementation.This is also key to fostering research activity in all parts of the world.
Published from January 2021 to August 8, 2023 Study design: empirical research using quantitative or qualitative design Children's data ( 18 years) analyzed separately from those of the adult population when both children and adults were assessed Patient-reported outcome measurement (PROM) • Used to advance knowledge of the condition and/or treatment • Development and psychometric evaluation • Assessment of PROM impact • Use in implementation studies (e.g., attempts to understand factors influencing implementation outcomes, use of implementation strategies, and process and outcome evaluation) Conditions treated in pediatric surgery: • Anorectal malformations gastrointestinal symptoms (PedsQL Gastrointestinal Symptoms [GI] Module) 98 or cognitive functioning (PedsQL Cognitive Functioning Scale [PedsCFS] 96,97 and Pediatric Perceived Cognitive Functioning Questionnaire [PedsPCF] 104,105 ).►Table 3 also lists the number of items included in each PROM, their domain coverage as per the Wilson and Cleary model, their use of patient input during the initial item generation phase of development, and the number of articles in which the PROM was applied, grouped based on intended application.Seven psychometrically robust PROMs used patient input during the initial item generation phase of development.

A
Narrative Review of PROMs and Their Application in Recent Pediatric Surgical Research Spivack and Dellenmark-Blom et al. 147

Fig. 2
Fig.2The number of articles employing the identified PROMs, categorized per condition.
mental, and social dimensions were measured; this was regarded as evaluation of overall quality of life independent of producing a total score or not.b 23 items for children aged 5-18, 21 for children aged 2-4.

Table 2
Selected articles categorized per condition studied and publication year

Table 2 (
Continued) Narrative Review of PROMs and Their Application in Recent Pediatric Surgical Research Spivack and Dellenmark-Blom et al. 149 European Journal of Pediatric Surgery Vol.34 No. 2/2024 © 2024.The Author(s).A

Table 2 (
Continued) Narrative Review of PROMs and Their Application in Recent Pediatric Surgical Research Spivack and Dellenmark-Blom et al. 151 European Journal of Pediatric Surgery Vol.34 No. 2/2024 © 2024.The Author(s).A

Table 2 (
Continued) Narrative Review of PROMs and Their Application in Recent Pediatric Surgical Research Spivack and Dellenmark-Blom et al. 153 Abbreviations: HRQoL, health-related quality of life; PROM, patient-reported outcome measure.European Journal of Pediatric Surgery Vol.34 No. 2/2024 © 2024.The Author(s).A

Table 3
Psychometrically robust PROMs 83,85,87-91,94-98,100,103-105 the PedsQL Gastrointestinal Symptoms Scale and 74 items for the Symptoms Module.Narrative Review of PROMs and Their Application in Recent Pediatric Surgical Research Spivack and Dellenmark-Blom et al. 155 significant impact on the quality of PROM research in health care and industry-based research.
f 58 items for European Journal of Pediatric Surgery Vol.34 No. 2/2024 © 2024.The Author(s).A 14,[106][107][108]Seven of the 12 psychometrically robust PROMs identified had been developed using patient input in the primary item generation development phase, which is in accordance with current PROM development standards.