Patient-Reported Outcome Measures for Pediatric Patients With Sport-Related Injuries: A Systematic Review Open Access

We conducted a computerized search of CINAHL, EBSCO, SPORTDiscus, and PubMed from inception to 2020 using the terms (sport-related OR sport OR athletic OR orthopedic OR orthopaedic) AND (youth OR adolescent OR child OR pediatric) AND (patient reported outcome OR patient rated outcome OR patient oriented outcome OR patient centered outcome) AND (instrument OR measure OR scale OR tool) for peer-reviewed articles. In addition to the computerized search, we contributed relevant articles and performed a manual search of reference lists and authors in the articles screened for inclusion to find relevant articles not identified in the initial search.

Duplicate articles were removed, and a 2-step process was used to identify relevant articles for this study (Figure 1). The titles and abstracts of all articles were screened by each author independently, using the inclusion and exclusion criteria. After the screening, a meeting was held to discuss articles that lacked consensus. We reviewed the full text of the remaining articles and met again to discuss any articles that did not receive a consensus.

Articles were included if they (1) were original research, (2) were written in English, (3) incorporated a PROM for sport-related injuries, and (4) involved participants ≤18 years of age. Studies were excluded if (1) the authors incorporated parent-generated responses or proxy reports on PROMs, (2) the authors focused on conditions outside of sport-related or orthopaedic injury, or (3) they were editorials, commentaries, case studies, guidelines, conference proceedings, or review articles. If the research involved participants <18 years old or proxy reports and we could feasibly separate the data and psychometrics of the instrument for the pediatric population, the study was included.

Articles were grouped according to the PROM(s) used, and instruments were then organized based on the region of focus: upper extremity, lower extremity, generic, single item, or activity. Considerations for clinical utility extracted from articles were acceptability (number of items, score range, time to complete, and readability; Table 1), feasibility (recall period, response format, grading, time to score, and anticipated costs; Table 2), and appropriateness (intended patient population and demonstrated use; Table 3).

Readability, including both the Flesch-Kincaid Reading Ease and Reading Grade Level formulas, was calculated for the unformatted text of each instrument using Word for Mac software (version 16.15; Microsoft Corp). Health-related quality of life is a global multidimensional concept that references an individual's unique life experiences and values and how they ultimately affect health and can be summarized through health domains and International Classification of Functioning (ICF) disablement levels.¹¹  Health domains (ie, physiological, physical, psychological, spiritual, social, economic) and ICF disablement levels (ie, body structure and function, activity, participation, environmental, personal) were determined based on a consensus method,¹¹  in which researchers with expertise in clinical outcomes assessment independently reviewed and rated each question in the included instruments to determine the primary health domain¹¹  and disablement level.²²  A more detailed description of these domains and disablement levels can be found in a previous investigation.¹¹  After the independent review, we convened to compare our individual ratings and agree on the final classification (Table 3).

Psychometric properties extracted from the articles were reliability (internal consistency, test-retest, interrater, intrarater), validity (face, criterion, construct, content, concurrent, discriminant, convergent or divergent), floor and ceiling effects (using a 15% threshold), responsiveness (effect size, minimal detectable change, standard error of measurement), interpretability (minimal clinically important difference, minimal important difference), and precision (type of score: binary, adjectival, visual analogue scale; Table 4).

The literature search resulted in 332 potential articles (Figure 1). After identifying and removing 94 duplicates, we screened the remaining 238 articles according to the inclusion and exclusion criteria. After the title and abstract review, 116 articles were removed, resulting in 122 articles for full-text review. We eliminated another 83 articles once the exclusion criteria were applied to the full text, leaving 39 articles (11.8%; Table 5) from which data were extracted and synthesized in the results. Among these 39 articles, a total of 22 PROMs were identified. Considerations for clinical utility are reported in Tables 1–3 and psychometric properties of each instrument in Table 4.

Four PROMs were identified for use with upper extremity conditions^23–28  and 5 for lower extremity conditions.^{19,20,29–39}  In addition, 4 generic,^{25,27,28,36,37,40–50}  4 single-item,^23,26,42  and 5 activity-based^{18,31,51–57}  instruments were identified. Twelve of the PROMs were developed specifically for the pediatric population,^{18,23,25,27,28,31–37,40–53,55–58}  3 were modified versions of an adult scale,^{20,23–29,31,36–39}  and 7 were adult measures used in a pediatric population^{18,23,26,29–31,36–38,42,54}  (Figure 2).

Despite a call to incorporate PROMs into all aspects of health care,^59,60  little is known about which measures are best suited for a pediatric patient population with sport-related injuries. Instruments are typically developed for specific patient populations, which can be problematic if clinicians and researchers expand their use beyond the originally intended group. Selecting and implementing PROMs that are suitable for youth and adolescents is challenging, and not all measures reflect the unique demands of this population.^17,19,20  Although the authors of a recent systematic review⁶¹  investigated the psychometric properties of PROMs used in the pediatric population, they did not report the specific psychometric findings, nor did they include several critical considerations related to the clinical utility of the measures (eg, readability, health domains, ICF disablement levels). To the best of our knowledge, we are the first to review the literature and assemble a repository of PROMs that are used by sports medicine health care professionals for pediatric patients, along with these associated variables. Our findings will help guide both clinicians and researchers in using PROMs in pediatric sports medicine.

The current standards for the development of a PROM, established by the Scientific Advisory Committee of the Medical Outcomes Trust,⁶²  consist of the following attributes: (a) the conceptual and measurement model, (b) reliability, (c) validity, (d) responsiveness, (e) interpretability, (f) the respondent and administrative burden, (g) alternative forms, and (h) cultural and language adaptation translations. Clinicians and researchers should consider these psychometric values when selecting an instrument, as adequate measurement properties of a PROM are essential to ensuring the integrity of an instrument and enabling the administrator to trust the quality of the information provided. In those instruments with reports of various types of validity (81.8%, 18/22 instruments) or reliability (72.7%, 16/22 instruments), the measurement qualities were sufficient (Table 4). For instance, the Activities Scale for Kids (ASK) demonstrated the highest value for test-retest reliability (intraclass correlation coefficient = 0.97),⁵¹  whereas the Multidimensional Fatigue Scale produced the highest value for internal consistency (Cronbach α = 0.95).⁵⁸  Additionally, the presence of floor or ceiling effects helps to determine how an instrument will perform in populations with broad ranges of function, those that experience extreme limits on function, or both. Floor or ceiling effects were not provided for 54.5% (12/22 instruments) of the PROMs (Table 4); however, a floor effect was observed for the Micheli Functional Scale³²  and a ceiling effect for the Marx Activity Scale.¹⁸  Most instruments lacked estimates of responsiveness (72.7%, 16/22 instruments) or interpretability (90.9%, 20/22 instruments; Table 4), which potentially limits our confidence in their ability to accurately measure change. Incorporating instruments into patient care without considering the associated psychometric properties can result in adverse consequences, including an increased burden on the patient, missing or unreliable data, or biased results.⁶³ 

Clinicians working with a pediatric population also need to choose PROMs that are age appropriate. The intended patient population for each of these instruments varies from children as young as 2 to 5 years old through adults. Readability formulae offer some indication of how easily a document is understood, and health literacy experts recommend that the maximum US reading grade level for a PROM used in a youth or adolescent population should be fifth to sixth grade.^64,65  Nonetheless, 40.9% (9/22) of the instruments assessed in this review exceed that threshold (Table 1). Interestingly, 3 of the PROMs that exceed the threshold were specifically developed for the pediatric population: the Micheli Functional Scale,³²  the Oxford Ankle Foot Questionnaire for Children (OxAFQ-C),^33–35  and the Hospital for Special Surgery Pediatric Functional Activity Brief Scale.^18,31,52,53  This is significant because if a patient is unable to understand the instrument, the other psychometric properties of the tool, such as validity and reliability, are assumed to be negatively affected.⁶⁶ 

Five of the 22 identified PROMs (22.7%) have acceptable measurement properties and readability levels (Tables 1 and 4). These instruments are the Youth Throwing Scale, Knee Injury and Osteoarthritis Outcome Score for Children (KOOS-Child), Pediatric International Knee Documentation Committee Subjective Knee Evaluation Form (Pedi-IKDC), Pediatric Quality of Life Inventory (PedsQL), and ASK. Each of these measures has reported acceptable reliability, validity, and responsiveness and meets the fifth- to sixth-grade readability threshold. However, we also need to balance these psychometric properties with practical considerations.

One factor in determining an instrument's clinical utility is the feasibility of administering the measure. Of the PROMs identified, none require clinician training, all are easy to administer, and each has a relatively quick time to completion (≤20 minutes; Table 2). Only the Child Health Questionnaire (CHQ)^36,37  requires a license, and both the CHQ^36,37  and Pediatric Outcomes Data Collection Instrument (PODCI)^27,49,50  were identified as long assessments (87 and 83 items, respectively). Several of the PROMs had identified recall periods (31.8%, 7/22 instruments), most of which lasted about a week. These findings provide a perspective on how often an instrument should be administered and should correspond with the purpose of the assessment. When choosing a PROM, clinicians and researchers should consider the length of the instrument as well as the documented recall period in order to match their patient care goals.

Estimating HRQOL helps to integrate the patient's perspective into health care and is an important component in delivering effective, whole-person, patient-centered care. Health-related quality of life is a multifaceted concept comprising several health domains; however, PROMs may assess only 1 or a few aspects.⁶³  In our review, nearly all of the PROMs included questions that addressed the physical health domain (90.9%, 20/22 instruments); most, the physiological domain (63.6%, 14/22 instruments); and a few, the social domain (36.4%, 8/22 instruments; Table 3). Regarding the ICF disablement levels, each PROM addressed either the body, structure and function level or the activity and participation level. Only 1 measure had questions related to environmental and personal factors (OxAFQ-C). Health-related quality of life is an important concept, as any of its constructs may be affected by a sport-related injury or health condition. Therefore, to provide patient-centered care, it is essential for clinicians and researchers to know which components are evaluated by the instruments of interest so that the PROM selected fulfills its intended purpose.⁶³ 

This systematic review was not without limitations. First, we chose not to include parent or proxy PROMs. Although these options may be appropriate to use in youth athletes, our intent was to focus specifically on identifying self-report instruments, as having patients assess their own HRQOL has been recommended.^67,68  Additionally, we did not include foreign-language translations of pediatric instruments; however, we did note if the included PROMs had additional versions available. Finally, we supplied the level of evidence for each included study (Table 1) but did not analyze the methodologic quality due to the varied study designs. Future researchers should address the gaps in the literature and continue to evaluate the psychometric properties and clinical utility of the PROMs identified in this systematic review. Furthermore, we observed that few PROMs address the spiritual, social, and economic health domains and the environmental and personal ICF disablement levels. Investigators should consider these areas when developing future PROMs for the pediatric sports medicine population.

In this systematic review, we provide insight into the PROMs used by athletic health care providers for pediatric patients with sport-related injuries. The measures identified are the most comprehensive in their development and generally have appropriate psychometric properties; however, most of the instruments require further evaluation. For example, reporting of interpretability and responsiveness is lacking, which may make it difficult to assess change over time. Most of the measures were short in length and feasible to administer; the recall period, readability, and areas of HRQOL the instruments measured varied. Furthermore, evidence indicates that adolescent athletes may be their own patient population⁴⁴  and may require PROMs developed specifically for them. Considering the acceptability, feasibility, appropriateness, and psychometric qualities, the OxAFQ-C and the PedsQL had the greatest number of items assessed and reported in the literature. Although a variety of instruments are presently used in pediatric sports medicine, clinicians and researchers should select a PROM that has appropriate psychometric evidence and meets both their goals and the goals of the patient.