More Realistic Spine Patients: Assessing the Effect of Dialogue Support Tool.

In Norway, data from the Norwegian Registry for Spine Surgery (NORspine) indicate that the proportion of patients reporting improvement 12 months after lumbar spinal surgery ("success rate") ranges from 63% to 67%. This suggests that a considerable proportion of patients remain dissatisfied, and that spinal surgery carries an inherent risk of symptom deterioration.

Studies have shown that patients frequently hold high preoperative expectations, yet only approximately 30% ultimately achieve their anticipated clinical outcome. Likewise, surgeons may overestimate the potential benefits of surgery while underestimating the likelihood of unfavourable outcomes.

The overall costs associated with spine surgery are substantial, and unsuccessful procedures have significant consequences for patients' health-related quality of life and impose a considerable economic burden on society. The advisory board of NORspine has therefore recommended that Norwegian hospitals promote studies to improve surgical outcomes.

Tools that improve surgeon-patient communication and facilitate patients' understanding of the medical information provided may be a useful strategy for reducing unfavourable outcomes. With the rapid advancement of digital technology and artificial intelligence, healthcare systems should consider implementing validated prognostic tools to support informed decision-making. However, these tools must undergo rigorous evaluation to ensure real-world applicability and to assess their impact on the healthcare system.

One such tool is the Dialogue Support (DS) application, an online platform based on the Swedish national quality register for spine patients (Swespine), designed to predict outcomes one year after surgery for degenerative spinal disorders. The DS application has been publicly available since October 2020 through a collaboration between the Eurospine steering board and the Swedish Society of Spinal Surgeons. The predicted outcomes are presented both numerically and graphically via a pie chart, thereby facilitating patients' comprehension of potential outcomes, including the possibility of symptom deterioration in the worst-case scenario. Additionally, second-opinion consultations may serve as a safeguard by providing patients scheduled for surgery or conservative treatment with repeated information.

This project will investigate the use of the DS application as a supplementary information and communication tool for patients with degenerative spinal disorders. The overarching aim is to improve patient treatment and specialised care through clinical research.

A multicenter superiority randomised controlled trial (RCT) will be conducted, in which the intervention consists of one additional study visit using the DS tool, referred to as the interventional arm. The RCT design ensures equal study groups and allows for comparison of groups treated during the same period, by the same surgeons, and under identical clinical guidelines, thereby effectively eliminating confounders and reducing bias.

All patients aged 18 years or older who are scheduled to undergo lumbar spinal surgery for disc herniation, spinal stenosis, or degenerative disc disease will be eligible for inclusion. Patients who do not understand spoken or written Norwegian will be excluded, as language barriers may interfere with the intervention study visit, comprehension of the information provided, and completion of study questionnaires. Additional exclusion criteria include patients with spondylolysis or lytic spondylolisthesis, as well as those already participating in other clinical studies.

Eligible patients will receive verbal and written information about the study and will sign an informed consent form if willing to participate. Randomisation will assign eligible patients to one of two arms: either one additional study visit prior to planned surgery without using the DS tool or one additional study visit using the DS tool. Blinding of patients and surgeons will not be feasible. To account for an anticipated dropout rate of 25%, a total of 440 patients will be included for analysis of the primary outcome. REDCap will be used for stratified block randomisation, with stratification based on diagnosis-disc herniation, spinal stenosis, or degenerative disc disease-to ensure balanced allocation across subgroups. Variable block sizes will be used to reduce the predictability of allocation sequences. Randomisation will be performed separately within each participating hospital to ensure balance between intervention and control groups and to minimise centre-related confounding.

All participants in both study arms will attend an additional outpatient clinic study visit scheduled about 2 to 6 weeks before surgery. This study visit will last 30 to 40 minutes and will be conducted either in person or via video consultation, according to patient's preference. Before the study visit, patients in both groups will complete a questionnaire to collect baseline data, as well as the Oswestry Disability Index (ODI) and EuroQol 5-Dimension 5-Level (EQ-5D-5L), in paper or electronic format.

The additional study visit will follow an identical framework in both study arms. In the intervention arm, the DS tool will be utilised, and these results, as well as the prognostic uncertainty, will be presented and explained to the patient. In the control arm, the DS tool will not be employed.

In both groups, patients will have the opportunity to ask questions about the surgical procedure, potential complications, hospitalisation, discharge, and the anticipated recovery period. The primary objective of the additional study visit is to improve patients' understanding of the surgical procedure and expected outcomes. This study visit is not intended to reassess or revisit the surgical indication.

Follow-up will be conducted at 3 and 12 months, in line with the Norwegian spine registry, and will include the same Patient-Reported Outcome Measures (PROMs) as the registry (ODI, NRS back and leg pain, GPE translation scale). This approach will facilitate collaboration with the Norwegian Spine Registry and minimise the number of follow-up forms for patients. Radiological examinations will not be performed as part of this study.

Four studies will be derived from this project.

• The first study will establish external validation of the DS tool using Norwegian registry data and assess inter-rater reliability. To the best of our knowledge, this is the first systematic assessment of DS interpretations among surgeons.
• The second study will provide new insights into how DS may influence patients' expectations.
• The third study will evaluate whether the use of DS improves surgical outcomes by providing better patient information. Ongoing studies on DS tools compare results from the DS tool with either historical data or results from other regions that do not use the DS tool. This RCT will compare patients from the same region and time period, ensuring equal surgical techniques and mindsets.
• The fourth study will assess whether the use of DS can reduce surgery cancellations and thereby contribute new data to health services research on efficiency, cost-effectiveness, and resource allocation in surgical care.

The primary outcome measure is the difference in mean ODI between the groups. We have deliberately chosen a target value of 5 points. Many studies are powered to detect differences of around 10 points, which is a relatively large difference; detecting or refuting it requires far fewer participants. In the present context, the study group considered a target value of 5 points a more appropriate aim for determining whether the intervention with an additional DS study visit would justify the use of resources and its implementation in clinical practice.

The primary analysis will be based on the intention-to-treat principle, whereby all randomised patients will be analysed according to the study arm to which they were originally assigned, regardless of protocol deviations. Patients who discontinue participation or are lost to follow-up will remain included in the intention-to-treat population. Additionally, a per-protocol analysis, including only patients who strictly adhere to the study protocol, will be performed and reported. Subgroup analysis will be conducted according to diagnosis category: disc herniation, spinal stenosis, and degenerative disc disease.

A statistician blinded to treatment allocation will analyse the primary and secondary outcome measures using masked group labels. Data will be analysed using standard methods, with descriptive statistics including means and 95% confidence intervals (CIs) for continuous variables and numbers with proportions for categorical variables. The main analyses comparing the two study groups will be based on Student's t-tests for independent groups (continuous outcomes) and chi-square tests (categorical outcomes). Where appropriate, mixed-effects models will be used to account for missing data. The study database will be locked before the final statistical analyses are initiated, after which no further data entry or modification will be permitted. A separate Statistical Analysis Plan (SAP) will provide detailed specifications for the planned analyses, including handling of missing data. The SAP will be finalised, dated, and signed before database lock and made publicly available through ClinicalTrials.gov. A study group meeting will be organised when 220 patients have completed the 3-month follow-up to review recruitment and response rates. Strategies to address non-response will be considered as needed.

The validation study will be an observational cohort study based on prospectively collected data from the Norwegian Spine Registry, including 1500 patients, with 500 in each of the diagnosis subgroups (disc herniation, spinal stenosis, or degenerative disc disease).