Identification of health trajectories of patients with persistent spinal pain syndrome type 2 using latent class trajectory methods

Abstract

Background: Persistent spinal pain syndrome Type 2 (PSPS-T2) is a long-lasting condition that consists of persistent pain following spinal surgery. Although this condition has long-term effects, it is currently studied at a given time point or over a limited period of time, which does not reflect the true impact of pain patients. To bridge this gap, we used latent class trajectory models to extract clusters with different trajectories of patients with PSPS-T2.

Materials and methods: Data from the PREDIBACK study, an observational, multicentric, and longitudinal investigation carried out prospectively, were used. This study focuses on patients with PSPS-T2, tracking their outcomes at 3-month intervals over a one-year period. Health status was evaluated using a novel multidimensional clinical response index (MCRI). The trajectories of patients' health status were extracted using mixture of mixed effect models.

Results: Two hundred (200) PSPS-T2 patients were included. Two clusters were identified, including 'persistent low health' trajectories (63.1%) and 'improving health' trajectories (36.9%). Regarding the factors associated with these trajectories, our results showed that lower age, lower body mass index, lower pain intensity, lower functional disability, lower anxiety and less extended pain surface were associated with improving health status.

Conclusion: Clustering methods provide an opportunity to identify two distinct clusters of pain-related health trajectories of PSPS-T2 patients. Persistence of the symptoms was not observed in one third of the PSPS-T2 study patients, who belong to the improving pain-related health cluster, while the other two thirds did not achieve improved health over a 1-year follow-up.

Significance statement: Our study findings suggest that the use of trajectory-based methods could improve patient evaluation and pain management as it allows for obtaining a global view of patients during their care pathway compared to conventional methods, which only focus on specific visits. Our study also advocates for multidimensional assessment and management of pain by targeting not only pain intensity but also the psychological distress, functional capacity and pain surface at an early stage of pain onset after spine surgery.