Patients undergoing surgery for lumbar spinal stenosis experience unique courses of pain and disability: A group-based trajectory analysis

Identifying Weekly Trajectories of Pain Severity Using Daily Data From an mHealth Study: Cluster Analysis

BACKGROUND

People with chronic pain experience variability in their trajectories of pain severity. Previous studies have explored pain trajectories by clustering sparse data; however, to understand daily pain variability, there is a need to identify clusters of weekly trajectories using daily pain data. Between-week variability can be explored by quantifying the week-to-week movement between these clusters. We propose that future work can use clusters of pain severity in a forecasting model for short-term (eg, daily fluctuations) and longer-term (eg, weekly patterns) variability. Specifically, future work can use clusters of weekly trajectories to predict between-cluster movement and within-cluster variability in pain severity.

OBJECTIVE

This study aims to understand clusters of common weekly patterns as a first stage in developing a pain-forecasting model.

METHODS

Data from a population-based mobile health study were used to compile weekly pain trajectories (n=21,919) that were then clustered using a k-medoids algorithm. Sensitivity analyses tested the impact of assumptions related to the ordinal and longitudinal structure of the data. The characteristics of people within clusters were examined, and a transition analysis was conducted to understand the movement of people between consecutive weekly clusters.

RESULTS

Four clusters were identified representing trajectories of no or low pain (1714/21,919, 7.82%), mild pain (8246/21,919, 37.62%), moderate pain (8376/21,919, 38.21%), and severe pain (3583/21,919, 16.35%). Sensitivity analyses confirmed the 4-cluster solution, and the resulting clusters were similar to those in the main analysis, with at least 85% of the trajectories belonging to the same cluster as in the main analysis. Male participants spent longer (participant mean 7.9, 95% bootstrap CI 6%-9.9%) in the no or low pain cluster than female participants (participant mean 6.5, 95% bootstrap CI 5.7%-7.3%). Younger people (aged 17-24 y) spent longer (participant mean 28.3, 95% bootstrap CI 19.3%-38.5%) in the severe pain cluster than older people (aged 65-86 y; participant mean 9.8, 95% bootstrap CI 7.7%-12.3%). People with fibromyalgia (participant mean 31.5, 95% bootstrap CI 28.5%-34.4%) and neuropathic pain (participant mean 31.1, 95% bootstrap CI 27.3%-34.9%) spent longer in the severe pain cluster than those with other conditions, and people with rheumatoid arthritis spent longer (participant mean 7.8, 95% bootstrap CI 6.1%-9.6%) in the no or low pain cluster than those with other conditions. There were 12,267 pairs of consecutive weeks that contributed to the transition analysis. The empirical percentage remaining in the same cluster across consecutive weeks was 65.96% (8091/12,267). When movement between clusters occurred, the highest percentage of movement was to an adjacent cluster.

CONCLUSIONS

The clusters of pain severity identified in this study provide a parsimonious description of the weekly experiences of people with chronic pain. These clusters could be used for future study of between-cluster movement and within-cluster variability to develop accurate and stakeholder-informed pain-forecasting tools.

Patient-level patterns in daily prescribed opioid dosage in single level lumbar fusion are associated with postoperative opioid dosage and adverse events: a retrospective analysis of claims data

BACKGROUND

Patients undergoing lumbar spine surgery have high rates of preoperative opioid use, which is associated with inferior outcomes and higher risks for opioid dependency postoperatively.

PURPOSE

Determine whether there are identifiable subgroups of patients that follow distinct patterns in pre- and postoperative opioid dosing. Examine how preoperative patterns in opioid dosing relate to postoperative opioid patterns, opioid cessation, and the risk for adverse events.

STUDY DESIGN/SETTING

Retrospective analysis of an administrative claims database (MeritiveTM Marketscan® Research Databases 2007-2015).

PATIENT SAMPLE

The 9,768 patients undergoing primary single level lumbar fusion.

OUTCOME MEASURES

Primary: daily morphine milligram equivalent (MME) opioid dosing calculated from prescriptions dispensed for 1 year before and after surgery; secondary: 90-day all-cause readmission and complications, 90-day acute postoperative pain, 90-day and 1-year reoperation, surgical costs, length of stay, and discharge disposition.

METHODS

Distinct patient subgroups defined by patterns of daily MME pre- and postoperatively were identified via group-based trajectory modeling. Associations between these groups and outcomes were assessed with multivariable logistic regression with risk adjustment for patient and surgical factors.

RESULTS

Among primary single level lumbar fusion patients, 59.5% filled an opioid prescription in the 3 months preceding surgery, whereas 40.5% were opioid naïve (Naïve). Five distinct subgroups of daily MME were identified among those filling opioids preoperatively: (1) Naïve to 3m (21.2% of patients): no opioids until 3 months preoperatively, escalating to 15 MME/day; (2) Low to 3m (11.4%): very low or as needed dose until 3 months preoperatively, escalating to 15 MME/day; (3) 6m Rise (6.9%): no opioids until 6 months preoperatively, escalating to >30 MME/day; (4) Medium (9.8%): increased linearly from 10 to 25 MME/day across the year before surgery; (5) High (10.0%): increased linearly from 60 to >80 MME/day across the year before surgery. These five preoperative opioid groups were related to postoperative opioids filled in a dose-response manner. The two preoperative patient groups with chronic Medium to High-dose opioid dosing were associated with increased adverse events, including all-cause readmission, reoperation, and pneumonia, whereas a low baseline group with a large, earlier preoperative rise in opioid dosing (6m Rise) had increased encounters for acute postoperative pain. Postoperatively, only 9.5% of patients did not fill an opioid prescription. Five distinct postoperative subgroups were identified based on their patterns in daily MME: Two groups ceased filling opioids within the year following surgery (33.6% of patients), and three groups declined in opioid dosage following surgery but plateaued at low (0-5 MME/day, 29.1%), medium (10-15 MME/day, 12.0%), or high (70-75 MME/day), 13.1%) doses by 1 year. Patients within the higher preoperative opioid groups were more likely to belong to the postoperative groups that were unable to cease filling opioids.

CONCLUSIONS

Identification of a patient's preoperative time trend in daily opioid use may provide significant prognostic value and help guide pain management and risk reduction efforts.

LEVEL OF EVIDENCE

III.

Disability and pain after anterior cervical decompression and fusion: A group-based trajectory analysis

OBJECTIVES

This study aimed to identify the clusters of patients with different developmental trajectories of pain and disability after anterior cervical decompression and fusion (ACDF).

METHODS

Group-based trajectory analysis among 318 patients undergoing the ACDF.

RESULTS

Three developmental trajectories of disability were identified: "Steadily good functioning," "Improved functioning," and "Steadily poor functioning." Three developmental trajectories of neck pain were identified: "Worsened pain," "Pain relief," and "Steadily severe pain." Two developmental trajectories of arm pain were identified: "Decreased arm pain" and "Severe arm pain with only short-term relief." No associations were found between sex, preoperative pain duration, or body weight and probability to be classified into a particular disability trajectory group. Female sex (relative risk ratio (RRR) 1.78) and longer history of preoperative pain (RRR 2.31-2.68) increased the probability to be classified into a group with steadily severe neck pain. Longer history of preoperative pain increased the probability to be classified into group with severe arm pain with only short-term pain relief (RRR 2.68).

CONCLUSION

After the ACDF, dissimilar developmental trajectories of pain and disability were identified between the patient clusters. While sex, preoperative pain duration, and body weight were not associated with differences in improvement in disability level, female sex and longer duration of preoperative pain were correlated with more severe neck and arm pain after surgery.

Postoperative Evaluation of Pain and Disability in Patients Undergoing Spinal Discectomy

BACKGROUND

A spinal discectomy surgery (SDS) is a common surgical procedure performed to treat lumbosacral radiculopathy.

AIM

To evaluate postoperative patterns of pain and disability in patients undergoing spinal discectomy.

METHODS AND MATERIALS

This investigation was a retrospective longitudinal review of prospective information gathered from 543 enrolled patients for lumbar radiculoplasty. The study participants were divided into two categories: Category 1 (SDS) comprising patients of lumbar radiculoplasty managed with SDS (n=270) and Category 2 (non-SDS) comprising patients of lumbar radiculoplasty managed with therapy other than SDS (n=273). It included study participants taking medication for pain control including opioids and non-opioids and physiotherapy for strengthening lower back muscles. At baseline, three months, 12 months, and 24 months after surgery, patient-reported information was gathered. Leg pain magnitude, back pain magnitude, and pain-related impairment were the key outcome metrics of interest.

RESULTS

The mean postoperative visual analog scale (VAS) score for leg pain at three-month follow-up was 4.3±1.2 in study participants in SDS and 8.1±1.3 in the non-SDS category. The VAS score was lower in the SDS category showing greater reduction in postoperative pain with statistically meaningful results (p<0.001). The mean postoperative VAS score at 12-month follow-up was 2.8±1.1 in study participants in SDS and 7.9±1.5 in the non-SDS category. The VAS score was lower in the SDS category showing greater reduction in postoperative pain with statistically meaningful results (p<0.001). The mean postoperative VAS score at 24-month follow-up was 1.7±1.2 in study participants in SDS and 7.1±1.1 in the non-SDS category. The VAS score was lower in the SDS category showing greater reduction in postoperative pain with statistically meaningful results (p<0.001).

CONCLUSION

 It was observed that after discectomy, patients suffering from lumbar radiculopathy have significant pain and disability recovery. According to these results, only a small percentage of individuals exhibit negative results at the level of impairment.

Impact of Undergoing Thoracolumbar Surgery on Patient Psychosocial Profiles

STUDY DESIGN

Prospective cohort study.

OBJECTIVE

Investigate the impact of thoracolumbar surgery on patients' psychosocial profiles.

METHODS

A prospective cohort study of thoracolumbar surgery patients (N = 177). Measures of interest collected at baseline and 24-months after surgery were: modified Oswestry Disability Index (mODI), Numerical Rating Scores for Back Pain (NRS-B), Leg Pain (NRS-L), Pain Catastrophizing Scale (PCS), Tampa Scale of Kinesiophobia (TSK), Chronic Pain Acceptance Questionnaire-8 (CPAQ-8), Multidimensional Scale of Perceived Social Support (MSPSS), Mental Component Summary (MCS) and patient expectations for surgery impacts on mental well-being. Cohorts were separated based on attaining meaningful change defined as either 30% improvement or minimal scores in NRS-B, NRS-L and mODI. Mixed measures ANOVAs were run (α = .05).

RESULTS

Patients who showed meaningful change had significant improvements in PCS, TSK and CPAQ-8 scores but not in MSPSS scores. Patients had improvement in MCS scores over 24-months follow-up, but this change was not significantly different based on attainment of meaningful change. Overall, 75.9% of patients reported their mental well-being expectations were met. Patients who did not achieve meaningful change showed no change on any psychosocial measures with only 55.9% reporting their mental well-being expectations met.

CONCLUSION

Thoracolumbar surgery results in significant improvement of psychosocial variables for patients who experienced meaningful change for pain and disability. Worsening of psychosocial health was not evident in patients who did not attain meaningful change.

A next-generation approach to mental health outcomes: Treatment, time, and trajectories

Over the last several decades, inpatient psychiatric length of stay (LOS) has been greatly reduced to the detriment of patients. Latent variable mixture modeling, can be used to improve the quality of care for patients by identifying unobserved subgroups and optimize treatment variables, including LOS. This study had three objectives (1) to replicate the findings made by Oh et al. in a distinct sample, (2) to examine demographic differences related to inpatient treatment trajectories, and (3) to relate additional variables to each trajectory. We collected data on six key mental illness factors and information on felonies, misdemeanors, history of stopping psychiatric medication and psychotherapy, length of time in psychotherapy, and the number of therapists and psychiatrists from 489 patients at an inpatient psychiatric hospital. We derived latent mental illness scores after applying growth mixture modeling to these data. We identified three distinct trajectories of mental illness change: High-Risk, Rapid Improvement (HR-RI), Low-Risk, Partial Response (LR-PR), and High-Risk, Gradual Improvement (HR-GI). The HR-GI group was more likely to have patients who were female, Asian, younger, Yearly Income (YI) <$20,000, that spent more time in psychotherapy throughout their life, and had the longest LOS while inpatient. The LR-PR group had was more likely to be male, Hispanic/Latino and multiracial, older, YI >$500,000, have a history of misdemeanors, and this group had the shortest LOS (p < .05). These findings replicate and extend our previous findings in Oh et al. (2020a) and highlight the clinical utility of agnostically determining the treatment trajectories.

The quality of life of 50-70 years old patients with orthopedic spinal stenosis surgery. A follow-up study (descriptive study)

Background

Background: Nowadays, surgical procedures are assessed based on the state of an individual. This study aimed to investigate the effect of lumbar spinal stenosis surgery on the patient's quality of life and motor functions in Kashani and Alzahra Hospital in Esfahan.

Methods

In the present cross-sectional study, 40 patients aged between 50-70 were respectively evaluated who underwent lumbar spine stenosis surgery in Al Zahra and Kashani Hospitals in Esfahan University of Medical Sciences, Esfahan, Iran, during 2020-2021. The SF-36 questionnaire was used as a research tool. The visual analog scale (VAS), and spine functional index (SFI), were measured initially before surgery and 6 months and 9 months after surgery.

Results

The mean scores of the SF-36, SFI, and VAS scores questionnaire were 87.95±4.94, 21.38±1.24, 6.07±0.69 (p<0.001) before surgery, 89.77±5.25, 19.73±1.40, 5.37±1.56 (p<0.001) six months after surgery, and 94.70±5.34, 18.63±1.56, 4.57±0.81 (p<0.001) nine months after surgery, and all were significant. Improvement in the domains of general health, role-physical, role disorder due to impaired physical health, social function, emotional role, and bodily pain was evident. Also, the overall quality of life was enhanced but energy levels and role disorder due to impaired mental health showed no improvement.

Conclusion

Not only does lumbar spinal stenosis surgery significantly improve the general health, role-physical, and the social function of the patients but also enhances their quality of life.

Variability in recovery following microdiscectomy and postoperative physiotherapy for lumbar radiculopathy: A latent class trajectory analysis

OBJECTIVES

The clinical course of lumbar radiculopathy following microdiscectomy and post-operative physiotherapy varies substantially. No prior studies assessed this variability by deriving outcome trajectories. The primary aims of this study were to evaluate the variability in long-term recovery after lumbar microdiscectomy followed by post-operative physiotherapy and to identify outcome trajectories. The secondary aim was to assess whether demographic, clinical characteristics and patient-reported outcome measures routinely collected at baseline could predict poor outcome trajectories.

METHODS

We conducted a prospective cohort study with a 24-month follow-up. We included 479 patients with clinical signs and symptoms of lumbar radiculopathy confirmed by Magnetic Resonance Imaging findings, who underwent microdiscectomy and post-operative physiotherapy. Outcomes were leg pain and back pain measured with Visual Analogue Scales, and disability measured with the Roland-Morris Disability Questionnaire. Descriptive statistics were performed to present the average and the individual clinical course. A latent class trajectory analysis was conducted to identify leg pain, back pain, and disability outcome trajectories. The best number of clusters was determined using the Bayesian Information Criterion, Akaike's information criteria, entropy, and overall interpretability. Prediction models for poor outcome trajectories were assessed using multivariable logistic regression analyses.

RESULTS

Several outcome trajectories were identified. Most patients were assigned to the 'large improvement' trajectory (leg pain: 79.3%; back pain: 70.2%; disability: 59.5% of patients). Smaller proportions of patients were assigned to the 'moderate improvement' trajectory (leg pain: 7.9%; back pain: 10.6%; disability: 20.7% of patients), the 'minimal improvement' trajectory (leg pain: 4.9%, back pain: 6.7%, disability: 16.3% of patients) and the 'relapse' trajectory (leg pain: 7.9%; back pain: 12.5%; disability: 3.5%). Approximately one-third of patients (32.6%) belonged to one or more than one poor outcome trajectory. Patients with previous treatment (prior back surgery, injection therapy, and medication use) and those who had higher baseline pain and disability scores were more likely to belong to the poor outcome trajectories in comparison to the large improvement trajectories in back pain, leg pain and disability, and the moderate improvement trajectory in disability. The explained variance (Nagelkerke R2) of the prediction models ranged from 0.06 to 0.13 and the discriminative ability (Area Under the Curve) from 0.66 to 0.73.

CONCLUSION

The clinical course of lumbar radiculopathy varied following microdiscectomy and post-operative physiotherapy, and several outcome trajectories could be identified. Although most patients were allocated to favorable trajectories, one in three patients was assigned to one or more poor outcome trajectories following microdiscectomy and post-operative physiotherapy for lumbar radiculopathy. Routinely gathered data were unable to predict the poor outcome trajectories accurately. Prior to surgery, clinicians should discuss the high variability and the distinctive subgroups that are present in the clinical course with their patients.

Postoperative recovery patterns following discectomy surgery in patients with lumbar radiculopathy

This retrospective study of prospectively collected data aimed to identify unique pain and disability trajectories in patients following lumbar discectomy surgery. Patients of this study population presented chiefly with lumbar radiculopathy and underwent discectomy surgery from thirteen sites enrolled in the CSORN registry. Outcome variables of interest included numeric rating scales for leg/back pain and modified Oswestry disability index scores at baseline, 3, 12, and 24 months post-operatively. Latent class growth analysis was used to identify distinct courses in each outcome. Data from 524 patients revealed three unique trajectories for leg pain (excellent = 18.4%, good = 55.4%, poor = 26.3%), disability (excellent = 59.7%, fair = 35.6%, poor = 4.7%) and back pain (excellent = 13.0%, good = 56.4%, poor = 30.6%). Construct validity was supported by statistically significant differences in the proportions of patients attaining the criteria for minimal important change (MIC; 30%) or clinical success in disability (50% or Oswestry score ≤ 22) (p < 0.001). The variable proportions of patients belonging to poor outcome trajectories shows a disconnect between improved disability and persistence of pain. It will be beneficial to incorporate this information into the realm of patient expectation setting in concert with future findings of potential factors predictive of subgroup membership.

Physical Predictors of Favorable Postoperative Outcomes in Patients Undergoing Laminectomy or Laminotomy for Central Lumbar Spinal Stenosis: Secondary Analysis of a Randomized Controlled Trial

Study Design

Secondary analysis of a randomized controlled trial.

Objective

To identify preoperative physical variables associated with favorable postoperative outcome in individuals undergoing laminectomy or laminotomy for degenerative central lumbar spinal stenosis.

Summary of Background Data

Clinical or condition specific variables have most commonly been studied as predictors of postoperative outcome in lumbar spinal stenosis. If associated to favorable postoperative outcome, modifiable physical variables would inform prehabilitation interventions for patients with degenerative central lumbar spinal stenosis.

Methods

Patients awaiting surgery for central lumbar spinal stenosis were recruited to participate in a randomized controlled trial. Following baseline data collection of demographics, clinical portrait and physical testing, participants were randomized to either 6-week active prehabilitation program or hospital standard care. Complete baseline and postoperative data were obtained from 58 participants which were included in the present analysis. Favorable postoperative outcome was determined based on two outcome measures. Favorable outcome was defined as a decrease of ≥30% on the Numerical Rating Scale for leg pain intensity and a decrease of ≥30% on the Oswestry Disability Index for low back disability. Baseline physical variables were used to conduct binary logistic regression.

Results

Sixty percent of participants were determined as having a favorable postoperative outcome. None of the included physical variables were found to be predictors of a favorable postoperative outcome based on leg pain intensity and low back pain-associated disability [trunk flexors muscle strength (OR = 0.73; 95%CI (0.02–27.12)] lumbar extensors muscle endurance [OR= 1.09; 95%CI (0.95–1.24)] total ambulation time [OR = 1.00 95%CI (0.99–1.01)] lumbar active range of motion in extension [OR = 1.08; 95%CI (0.95–1.23)] and knee extensors muscle strength [OR=1.02; 95%CI (0.98–1.06)].

Conclusion

Results show that none of the investigated variables, all related to low back and lower limbs physical capacity, were predictors of postoperative recovery. Further testing in larger cohort is needed to assess the full potential of physical outcome measures as predictors of postoperative recovery.

Construct validity and responsiveness of commonly used patient reported outcome instruments in decompression for lumbar spinal stenosis

BACKGROUND

Validity and responsiveness of Oswestry disability index (ODI), Roland Morris disability questionnaires (RMDQ), Short Form-12 Physical Component Score (SF-12 PCS) and Short Form-12 Mental Component Score (SF-12 MCS) in patients undergoing open decompression for lumbar canal stenosis has not been previously reported.

METHODS

Outcome assessment was prospectively evaluated using the ODI, RMDQ, SF-12 PCS and SF-12 MCS pre-intervention and at average follow-up of three months post-intervention. Pearson correlation coefficient was used to evaluate the association between change in values of ODI, RMDQ, SF-12 PCS and SF-12 MCS. Distribution based methods (Effect size [ES], standardised response mean [SRM]) and anchor based method (Area under the curve [AUC] of receiver operating curve [ROC]) were used to determine responsiveness. AUC value ≥ 0.70 is considered as adequate level of responsiveness and the outcome instrument with the largest AUC is considered to be the most responsive outcome instrument.

RESULTS

This study included 77 participants. Responsiveness was assessed at a mean follow-up of 12 weeks postoperatively. There was significant strong correlation between ODI and RMDQ (r = 0.65, p < 0.0001). The ES of ODI, RMDQ, SF-12 PCS and SF-12 MCS were 1.54, 1.48, 1.85 and 0.51 respectively. The SRM of RMDQ, ODI, SF-12 PCS and SF-12 MCS were 1.22, 1.17, 1.0 and 0.47 respectively. AUC of ODI, RMDQ, SF-12 PCS and SF-12 MCS were 0.83-0.88, 0.82 to 0.86, 0.78 to 0.81 and 0.69 to 0.70 respectively.

CONCLUSION

It is recommended to use either ODI or RMDQ as region specific patient reported outcome instrument and SF-12 PCS as a health related quality of life outcome instrument to evaluate outcome after decompressive laminectomy for lumbar canal stenosis.

The impact of multijoint symptoms on patient-reported disability following surgery for lumbar spine osteoarthritis

BACKGROUND CONTEXT

In the lumbar spine osteoarthritis (LS-OA) population having surgery for lumbar spinal stenosis (LSS) symptoms, a significant proportion of patients experience limited benefit following the intervention. Thus, identifying contributing factors to this is important. Individuals with OA often have multiple joint symptoms, yet this has received limited attention in this population.

PURPOSE

Document the occurrence of joint symptoms among patients undergoing surgery for LS-OA, and investigate the influence of these symptoms on disability postsurgery.

DESIGN

Prospective study of consecutive patients followed to 12-month postsurgery.

PATIENT SAMPLE

Patients undergoing surgery (decompression surgery, with or without fusion) for neurogenic claudication with or without back pain due to LSS with a primary pathology diagnosis of LS-OA.

OUTCOMES MEASURES

Patient self-reported: Oswestry Disability Index (ODI), completed pre- and 12-month postsurgery; and, completed presurgery, age, sex, education, smoking, comorbid conditions, opioid use, short/long-term disability, depression and anxiety symptoms, back and leg pain intensity, presence of spondylolisthesis, procedure, prior spine surgery, and joints with arthritis and "pain/stiffness/swelling most days of the month" indicated on a homunculus (a joint site count was derived).

ASSESSMENTS

Height and weight, used to calculate body mass index; timed-up-and-go performance-based test.

METHODS

Outcome of interest was achieving a clinically important improvement (CII) in ODI by 12-month postsurgery (yes/no). The association between joint site count and achieving a CII was examined by multivariable logistic regression analyses, adjusted for other measures.

RESULTS

In all, 165 patients were included. The mean age was 67 years (range: 44-90) and 47% were female. Seventy-seven percent reported 1+ joint site other than the back, 62% reported 2+, and 25% reported 4+. Among those achieving a CII, 21% had 4+ joint sites, compared with 31% among those not achieving a CII. Adjusted analyses: Increasing joint site count was associated with increasing risk (odds ratio [OR]: 1.32, 95% confidence interval [CI]: 1.05, 1.66) of not achieving a CII; for those with 4+ joints, adjusted probability of not achieving a CII exceeded 50%. Also associated with an increased risk of not achieving a CII was presurgery anxiety (OR: 2.97, 95% CI: 1.02, 8.65), opioid use (OR: 2.89, 95% CI: 1.07, 7.82), and worse back pain intensity score (OR: 1.27, 95% CI: 1.05, 1.53).

CONCLUSIONS

Multijoint involvement was highly prevalent in this LS-OA surgical sample. Its association with poorer postsurgery outcome supports a comprehensive approach to OA management and care. Knowledge of multijoint symptoms should inform patient education, shared decision-making, and recommendations for postsurgical rehabilitation and self-management strategies.

Trajectories of Disability and Low Back Pain Impact: 2-year Follow-up of the Groningen Spine Cohort

STUDY DESIGN

Prospective cohort study.

OBJECTIVE

The aim of this study was to identify treatment response trajectories in patients with low back pain (LBP) during and after multidisciplinary care in a tertiary spine center, and to examine baseline patient characteristics that can distinguish trajectories.

SUMMARY OF BACKGROUND DATA

Treatment response is often heterogeneous between patients with LBP. Knowledge on key characteristics that are associated with courses of disability could identify patients at risk for less favorable outcome. This knowledge will help improve shared decision-making.

METHODS

Adult patients with LBP completed questionnaires on disability (Pain Disability Index) and LBP impact (Impact Stratification of the National Institutes of Health minimal dataset) at baseline, 6, 12, 18, and 24 months' follow-up. Latent class analyses were applied to identify trajectories of disability and LBP impact. Baseline sociodemographic and clinical patient characteristics were compared between trajectory subgroups.

RESULTS

Follow-up was available for 996 patients on disability and 707 patients on LBP impact. Six trajectories were identified for both outcome measures. Three disability trajectories remained stable at distinct levels of severity (68% of patients) and three trajectories showed patterns of recovery (32%). For LBP impact there was one stable trajectory (17%), two slightly improving (59%), two recovering (15%), and one with a pattern of recovery and relapse (15%). Significant differences between trajectories were observed for almost all baseline patient characteristics.

CONCLUSION

On average, patients show moderate improvements in disability and LBP impact 2 years after visiting a multidisciplinary tertiary spine center. However, latent class analyses revealed that most patients belong to subgroups experiencing stable levels of disability and LBP impact. Differences in baseline patient characteristics were mostly associated with baseline levels of functioning, instead of (un)favorable outcome during follow-up.

LEVEL OF EVIDENCE

2.

Preoperative Factors Predict Postoperative Trajectories of Pain and Disability Following Surgery for Degenerative Lumbar Spinal Stenosis

STUDY DESIGN

Longitudinal analysis of prospectively collected data.

OBJECTIVE

Investigate potential predictors of poor outcome following surgery for degenerative lumbar spinal stenosis (LSS).

SUMMARY OF BACKGROUND DATA

LSS is the most common reason for an older person to undergo spinal surgery, yet little information is available to inform patient selection.

METHODS

We recruited LSS surgical candidates from 13 orthopedic and neurological surgery centers. Potential outcome predictors included demographic, health, clinical, and surgery-related variables. Outcome measures were leg and back numeric pain rating scales and Oswestry disability index scores obtained before surgery and after 3, 12, and 24 postoperative months. We classified surgical outcomes based on trajectories of leg pain and a composite measure of overall outcome (leg pain, back pain, and disability).

RESULTS

Data from 529 patients (mean [SD] age = 66.5 [9.1] yrs; 46% female) were included. In total, 36.1% and 27.6% of patients were classified as experiencing a poor leg pain outcome and overall outcome, respectively. For both outcomes, patients receiving compensation or with depression/depression risk were more likely, and patients participating in regular exercise were less likely to have poor outcomes. Lower health-related quality of life, previous spine surgery, and preoperative anticonvulsant medication use were associated with poor leg pain outcome. Patients with ASA scores more than two, greater preoperative disability, and longer pain duration or surgical waits were more likely to have a poor overall outcome. Patients who received preoperative chiropractic or physiotherapy treatment were less likely to report a poor overall outcome. Multivariable models demonstrated poor-to acceptable (leg pain) and excellent (overall outcome) discrimination.

CONCLUSION

Approximately one in three patients with LSS experience a poor clinical outcome consistent with surgical non-response. Demographic, health, and clinical factors were more predictive of clinical outcome than surgery-related factors. These predictors may assist surgeons with patient selection and inform shared decision-making for patients with symptomatic LSS.

LEVEL OF EVIDENCE

2.