Great Diversity Found in Outcome Domains Used in Adult Spinal Deformity Studies

Marinus de Kleuver MD, PhD, and Miranda van Hooff, PhD, comment on findings from the first phase of this international project, and Kevin R. O’Neill, MD, MS, provides his insights.

New research shows “great diversity” in outcome domains and patient-reported outcome measures (PROMs) used in 144 studies on adult spinal deformity (ASD) surgery published between 2000 and 2015, according to a study in the August issue of the European Spine Journal.

The study, which was partly funded by a grant from AOSpine, is “a first and important step toward establishing a global standard set of outcomes that matter to patients for which international consensus (among professionals and patients) will be reached. Such a standard set is important to have and to implement in daily routine practice in order to speak the same language,” said principal investigator Marinus de Kleuver MD, PhD, Professor and Head of the Orthopaedic Department at Radboud University Medical Center, Nijmegen, The Netherlands.
Puzzle piece with the word "Outcomes"The findings are part of a 2-part project with the overall goal of “reaching an international consensus on a patient-relevant standard set of core outcome domains. Photo Source:123RF.comThe findings are part of a 2-part project with the overall goal of “reaching an international consensus on a patient-relevant standard set of core outcome domains (eg, walking, sensation of pain, pulmonary function and patient satisfaction) and accompanying measurement instruments (eg, Oswestry Disability Index and/or Scoliosis Research Society [SRS-22]). This includes risk and case-mix factors to adjust outcomes," explained co-author, and overall project coordinator Miranda van Hooff, PhD, clinical epidemiologist, Radboud University Medical Center.

“The derived core outcome set will be recommended to be included in international and national spine outcome registries for continuous quality of care monitoring and use in future clinical research with patients with spinal deformity undergoing reconstructive surgery,” Dr. de Kleuver said. “When universally applied, this contributes to facilitate international comparisons and benchmarking, ultimately enhancing value-based spine care.”

The present study describes findings from the first phase of the international project, which is a systematic review of the literature performed to identify currently used PROMs and measured outcome domains in ASD surgery.

Systematic Literature Review Reveals Gaps in Outcomes Measures

“We identified 9 frequently used PROMs that were linked to 29 outcome domains, covering 3 out of 4 main chapters of the World Health Organization’s International Classification of Functioning and Health framework: body function (n=7), activity and participation (n=19), and environmental factors (n=3),” Sayf S.A. Faraj (PhD student) and lead author said. “It is remarkable that outcome domains related to neurological function (eg, muscle power function, bladder, or bowel functions) and pulmonary function are not evaluated by PROMs in the current literature even though both observed to be affected before and after ASD surgery. Although we expect these outcomes to be of relevance to patients, the question remains whether this holds true in the future," explained Dr. de Kleuver.

“The outcome domains related to walking, mobility, and sensation of pain were well represented and duly covered, but a great diversity in measurement instruments used was seen,” Dr. de Kleuver told SpineUniverse. The authors believe the variability in outcome domains found in the literature hampers the ability to comparing results and outcomes.

“As treatment outcomes could be regarded as a 'proxy' for the quality of care delivered, any future benchmark is limited,” Dr. de Kleuver said. “In light of patient-centered care and increasing healthcare costs, this has direct implications for international data pooling and benchmark of standardized, for risk and case-mix adjusted outcomes, and most importantly for future value-based spine care.”

“Furthermore, we found the level of clinimetric quality of PROMs used in this specific population was rather poor,” Dr. de Kleuver said. The highest level was found for the SRS-22. More research is needed to evaluate the methodological (ie, clinimetric) properties of PROMs used in ASD.”

“This group is to be commended on their effort and contribution in seeking to improve our measurement of patient reported outcomes for adult spinal deformity surgery,” commented Kevin R. O’Neill, MD, MS, who is a spine surgeon at OrthoIndy, Inc., Indianapolis, IN, and a member of the SpineUniverse Editorial Board. “It gives insight into the depth of scientific rigor necessary to develop an adequate measuring tool to answer a seemingly basic and fundamental question—are we helping patients with our treatment? This is yet another step forward in the continuously evolving effort to improve our outcome measurements. As the authors point out, this will be useful in developing the next iteration of an outcome measurement for adult spinal deformity surgery.”

Next Steps

With grant funding from the Scoliosis Research Society, the researchers’ next step is to use a Delphi method to develop a set of core outcome domains and accompanying PROMs based on the list of outcome domains identified in the current study. The domains will be assessed in three rounds using a formal international consensus process of a multidisciplinary group of 25 experts in ASD. This will be followed by two rounds to reach consensus on accompanying PROMs and/or clinical outcome measures to cover the outcome domains, including a patient panel to validate the set.

“It is of utmost importance to internationally agree upon a core set of outcome domains, measurement instruments and predictive factors contributing to these outcomes (ie, risk and case-mix factors),” Dr. de Kleuver concluded.

Updated on: 03/19/19
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