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The PedsQL™: 30 years in the making

Authors

John Connelly, MA1; Catherine Acquadro, MD2; Cécile Perret, PhD2
1Boston University, Boston, Mass., USA
2Mapi Research Trust, Lyon, France


The year was 1981. James Varni, who had received his Ph.D. in psychology only five years earlier from UCLA, had just published the first article to ever run in the journal Pain1 on the subject of pediatric self-reported pain. In this article, Jim discussed the methodology he had developed to measure pain and associated measures and the possibility that children could self-report their pain and general wellbeing from a young age. “Back in those days there was a lot of skepticism that anyone could get young children to accurately selfreport on matters of their health and well-being,” Jim said.
Little did he know back then that this methodology would become widely accepted and evolve into one of the world’s most frequently used pediatric Patient-Reported Outcome (PRO) instruments: the Pediatric Quality of Life Inventory™ (PedsQL™ for short).
Dr. Varni started thinking about measuring the perceptions of very young children in the late 1970s but didn’t work out the best way to do it until the early ’80s. “It started when I was a postdoctoral fellow in the Department of Pediatrics working with kids with burns while at The Johns Hopkins University Medical Center and later with children with hemophilia at Children’s Hospital Los Angeles. I wanted to help these kids manage their pain but realized that I couldn’t develop an ideal pain management plan unless I could measure their perceptions of their pain…as they felt it and self-reported it.”

The PedsQL and its global reach

It took more than 15 years of testing and perfecting his concept before he was ready to give his Pediatric Quality of Life Inventory a global launch. Though the PedsQL was formally introduced in 1998 through its own website (www.pedsql.org), it received a real boost among the HRQL community in a lengthy 1999 article authored by Dr. Varni et al. in the journal Medical Care.2
One only needs to consider a few facts to realize the impact that the PedsQL questionnaire, in its various scales and modules, has made internationally. Over the past 15 years, it has been:

  • Used to measure the quality of life of roughly 200,000 children and adolescents worldwide
  • Translated into more than 85 languages
  • Put to use in well over 100 countries
  • Cited in nearly 1,000 peer-reviewed research journal publications

Perhaps most gratifying to Jim Varni, the PedsQL has proven to be equally effective as a measurement instrument with (a) pediatric patients with acute and chronic health conditions; (b) poor and disadvantaged children and adolescents in developing countries; and (c) with healthy school children virtually everywhere.

What distinguishes the PedsQL

Dr. Varni believes one of the things that has set the PedsQL apart is that it is the only empirically derived health-related quality-of-life instrument that has demonstrated data-based evidence that children as young as five years of age, when given an age-appropriate measure, can self-report their own health-related quality of life (HRQL). “Hearing the voices of the children in matters of their own health and wellbeing, from the youngest children empirically feasible, has been the overarching objective of the PedsQL,” Dr. Varni told us. “The success we’ve seen with very young children supports its use as designed.”

The PedsQL takes a modular approach in measuring the HRQL of children and adolescents. It consists of brief, practical, generic core scales that work well when used with healthy school and community populations as well as with those with acute and chronic health issues. A wide range of PedsQL conditionspecific modules complement the generic core scales for use in specific clinical populations.
Jim cautions that pediatric HRQL measurement instruments must be sensitive to cognitive development and must include both children’s selfreports and parents’ proxy-reports to be most effective. Accordingly, his PedsQL Measurement Model consists of four developmentally appropriate forms: for children 2 to 4, 5 to 7, 8 to 12, and 13 to 18 years of age. Pediatric self-reports are measured in children and adolescents from 5 to 18 years while his parent proxy-reports of a child’s HRQL are measured for those from age 2 through 18.
Pediatric HRQL instruments, Dr. Varni believes, must have a clear conceptualization of the HRQL construct for pediatric populations. For him, an effective pediatric HRQL instrument should be multidimensional, consisting—at a minimum—of the physical, mental, and social health generic core dimensions as delineated by the World Health Organization (WHO) in 1948.
His 23-item PedsQL Generic Core Scales measure these WHO-based core dimensions of health as well as role (school) functioning. Thus, the multidimensional PedsQL Generic Core Scales encompass four essential core domains for pediatric HRQL measurement: (a) Physical Functioning (8 items); (b) Emotional Functioning (5 items); (c) Social Functioning (5 items); and (d) School Functioning (5 items). The Generic Core Scales are printed on one side of one sheet of paper, with the instructions on the other side. Each PedsQL age-appropriate form takes less than four minutes to complete.
Dr. Varni notes that while debate continues on the relative merits of a generic-specific vs. a diseasespecific approach to measuring HRQL, recent conceptual models indicate the advantages of an integrated modular approach to HRQL measurement. “The PedsQL Measurement Model integrates seamlessly both generic core scales and disease-specific modules into one measurement system,” Jim said. “The PedsQL Generic Core Scales are designed to enable comparisons across patient and healthy populations. The complementary PedsQL chronic health condition modules are designed to provide greater measurement sensitivity for circumscribed clinical populations.”
Thus, the PedsQL Measurement Model combines the clinical utility and sensitivity of a disease-specific measure and the applicability of generic core scales across both patient and healthy populations, with healthy population norms for benchmarking purposes and community-health comparisons.

How the PedsQL has evolved

The PedsQL builds on and expands a programmatic, instrumentdevelopment effort by Dr. Varni and his associates over the past 30 years. The PedsQL 1.0, originally derived from a pediatric cancer database, was designed as a generic quality-of-life inventory to be utilized noncategorically, i.e., across multiple pediatric populations.
“I’ve found that, to be truly successful, instrument development must be an iterative process,” Dr. Varni noted. “The PedsQL 2.0 and 3.0 were further advancements in the measurement model, including additional constructs and items, a more sensitive scaling range, and a broader age range for patient selfreport and parent proxy-report.”
The PedsQL has resulted from a rapid cycle-improvement strategy, and has been field tested with children and adolescents in pediatricians’ offices, hospital specialty clinics, and various community settings internationally. The PedsQL Generic Core Scales are currently in use in healthcare settings across the US, as well as by the Departments of Health of many states as a straightforward way to monitor the health status of large numbers of both ill and healthy children. One of the largest studies that used the PedsQL3 took place in California in 2003. With over 10,000 children in the study, the state was able to evaluate how well its health insurance program was doing in terms of health outcomes. To ensure that results will be culturally relevant and linguistically harmonized, the PedsQL has been translated and linguistically validated from US English into dozens of languages by Mapi Linguistic Validation.
As of this writing, PedsQL Disease- Specific Modules are available for numerous pediatric chronic health conditions, such as asthma, arthritis, cancer, cardiac disease, diabetes, Duchenne muscular dystrophy, endstage renal disease, eosinophilic esophagitis, neurofibromatosis, neuromuscular disease, and sickle cell disease. Modules and scales also exist for pediatric pain, fatigue, and transplant patients, as well as a family impact module for families with children with chronic health conditions.
When we asked Jim what’s in store for the PedsQL, he told us that he plans to develop several more disease-specific modules. “We introduced the Pediatric Sickle Cell Disease Module in an article published this year in the journal Pediatric Blood and Cancer.4” He then mentioned that he plans on bringing out a Gastrointestinal Symptoms Module in 2014. “Right now nine children’s hospitals across the US are beta-testing this module for us,” he added.
As to the most recent developments, the drug Soliris (ecalizumab) was approved with a PRO labeling claim by the EMA5 on April 29th of this year for the treatment of paroxysmal nocturnal haemoglobinuria, with the submission of a PRO endpoint including the PedsQL 4.0 Generic Core Scales (physical, emotional, social, and school functioning) and the PedsQL Multidimensional Fatigue questions and scores.
A disease-specific module of the PedsQL, the PedsQL 3.0 Neuromuscular Module (NMM), has recently become available that could be administered together with the PedsQL 4.0 Generic Core Scales. Using the PedsQL Generic Core Scales in combination with the Neuromuscular Module was mentioned in an EMA draft guideline6 published in March 2013 as a secondary endpoint to assess the quality of life of patients with Duchenne and Becker muscular dystrophy.
Finally, Jim wasn’t satisfied that the lowest age limit of parent proxyreport scales had been at the toddler stage, around two years old. So his team developed the parent proxyreport PedsQL Infant Scales geared to assess the well-being of babies from the age of one month up to 24 months. Mapi is presently involved in the linguistic validation of 46 international translations of these landmark infant scales.

How the PedsQL measures up

The PedsQL Generic Core Scales and its various disease-specific modules represent a substantive advancement in pediatric HRQL measurement, combining the reliability, validity, responsiveness, and practicality not typically found in an “all-in-one” pediatric HRQL instrument.
In study after study, internal consistency reliability of the PedsQL has been excellent, with alphas for the generic core scales in both selfand proxy-reports greater than the 0.70 standard, and alphas for the full 23-item scale approaching 0.90 for self- and proxy-reports. Missing data were minimal. Item response distributions were across the fullscale range, with no floor effects, and minimal ceiling effects.7
The validity of the PedsQL Generic Core Scales has been demonstrated through known group comparisons, and correlations with other measures of disease burden. These scales are also responsive to clinical changes, as demonstrated in field trials.7 (To learn more, see “Publications” at www.pedsql.org)
Dr. Varni believes that researchers, policy-makers, providers, and health plans that employ the PedsQL instrument will find it to be a welcome addition in their evaluation of pediatric health outcomes. Long term, Jim sees the PedsQL will be used more and more as an outcome measure for pediatric healthcare. “The Affordable Care Act goes into effect across the US in January 2014. If it functions the way it is supposed to, it should lead to far more medical facilities focusing on health outcomes and improvements in quality of life,” Jim told us. “The PedsQL is designed to measure such data.”
Dr. Varni is also encouraged that the PedsQL is being used for people of all ages. “Though it was designed for pediatric patients, because it is so easy to use it can work well with adult patients,” he said. “We’re always happy to adapt the core scales and modules for such populations and purposes.”

Keeping up with Dr. Varni

Jim Varni has never been one to sit still-or rest on his laurels. A Fellow of the American Psychological Association, he has published over 290 peer-reviewed research journal articles and numerous book chapters in pediatric behavioral medicine, and has written four books on children and families. His publications range broadly from behavioral medicine to environmental design. All told, Jim’s work has been cited in peer-reviewed journals more than 10,000 times in just the last five years.
Though he will claim his primary areas of expertise are measurement instrument development, conceptual models, and cognitive-behavior therapy interventions in pediatric chronic health conditions, Jim has been involved in several other fields, including architecture.
One of his passions combines these interests: conducting research and evaluating the healing environment of children’s hospitals, focusing on the effect of the way structures are built and how these environments influence child, parent, and staff outcomes. “I believe in evidence-based architectural design for pediatric healthcare facilities, including pediatric healing gardens,” Jim added. “You’d be surprised the impact they can have on quality of life.”

How to get and use the PedsQL

Since 2002, Mapi Research Trust (MRT) has been the sole international distributor for the PedsQL Generic Core Scales and its disease-specific modules.
Dr. Varni has selected Mapi as the exclusive linguistic validation company to ensure the production of harmonized and consistent language versions of the PedsQL. For more information on Mapi’s unique linguistic validation methodology, please visit https://mapigroup.com/services/language-services/
To learn more about the many PedsQL modules and scales and how to get access to them for your research study, go to www.pedsql.org or contact MRT by email at PROinformation@mapi-trust.org.

Acknowledgments

The authors would like to warmly thank Dr. James Varni for his enthusiasm and availability during the interview and permission to use the information from the PedsQL website.
James W. Varni, Ph.D., is a Professor and Vice Chair for Research, College of Medicine, and Professor and holder of the Julie and Craig Beale 1971 Endowed Professorship in Health Facilities, Center for Health System + Design, Department of Landscape Architecture and Urban Planning, College of Architecture, Texas A&M University at College Station, Texas, USA. He is also a recipient of the Significant Research Contributions Award from the American Psychological Association. He can be reached by email at jvarni@arch.tamu.edu.

References

  1. Varni JW, Gilbert A, Dietrich SL. Behavioral medicine in pain and analgesia management for the hemophilic child with Factor VIII inhibitor. Pain 1981;11:121-126
  2. Varni JW, Seid M, Rode CA. The PedsQL™: Measurement model for the Pediatric Quality of Life Inventory, Medical Care 1999;37:126-139
  3. Varni JW, Burwinkle TM, Seid M, et al. The PedsQL 4.0 as a pediatric population health measure: Feasibility, reliability, and validity. Ambulatory Pediatrics 2003; 3:329-341
  4. Panepinto JA, Torres S, Bendo CB, et al. PedsQL™ Sickle Cell Disease Module: Feasibility, reliability and validity. Pediatric Blood & Cancer 2013; 60:1338-1344
  5. European Medicine Agency. Soliris: EPARProduct information, 2013. Available at http:// www.ema.europa.eu/docs/en_GB/document_ library/EPAR_-_Product_Information/ human/000791/WC500054208.pdf (as accessed on August 26, 2013)
  6. Committee for Medicinal Products for Human Use – European Medicine Agency. Draft guideline on the clinical investigation of medicinal products for the treatment of Duchenne and Becker muscular dystrophy, 2013. Available at http://www.ema.europa. eu/docs/en_GB/document_library/Scientific_ guideline/2013/03/WC500139508.pdf (as accessed on August 26, 2013)
  7. Varni JW and Limbers CA. The Pediatric Quality of Life Inventory: Measuring pediatric health-related quality of life from the perspective of children and their parents. Pediatric Clinics of North America 2009;56:843-863