Predicting back pain treatment outcomes among workers' compensation patients: important information for clinical neuropsychologists

Vertebroplasty and Return to Work for Thoracolumbar Fractures Within the Workers' Compensation Population

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

Analyze efficacy of vertebroplasty and its affect on return to work (RTW) in a workers' compensation (WC) population SUMMARY OF BACKGROUND DATA.: Vertebroplasty remains a controversial treatment modality for vertebral compression fractures (VCFs). No studies have analyzed use of vertebroplasty in the clinically distinct WC population.

METHODS

A total of 371 Ohio WC subjects were identified who sustained VCFs and were treated with either vertebroplasty or conservative medical therapy between 1993 and 2013 using Current Procedural Terminology procedural and International Classification of Diseases, Ninth Revision diagnosis codes. Subjects with a prior smoking history, prior thoracolumbar surgery or comorbidities, or underwent decompression and/or fusion within 3 months after injury were excluded. Forty-six subjects had undergone vertebroplasty within 1 year of injury and were therefore included in the vertebroplasty group. The remaining 325 subjects received spinal orthosis and formed the control group. The primary outcomes were whether subjects returned to work at early and late time points. Early RTW was defined as returning to work within 3 months and remaining at work for more than 6 months of the following year. Late RTW was defined as returning to work within 2 years and remaining at work for more than 6 months of the following year. Secondary outcomes included opioid use, all-cause mortality, and additional VCFs.

RESULTS

Approximately 37% (17/46) of vertebroplasty group made an early RTW, compared with 35.4% (115/325) of control group (P = 0.835). Regarding late RTW, only 54.3% (25/46) of vertebroplasty group made a sustainable RTW, compared with 70.8% (230/325) of subjects in control group (P = 0.025). In addition, the vertebroplasty group was associated with significantly higher postoperative opioid use.

CONCLUSION

Vertebroplasty may not be an effective treatment modality for VCFs in the WC population when RTW is the primary goal.

LEVEL OF EVIDENCE

3.

Return to Work After Diskogenic Fusion in Workers' Compensation Subjects

Lumbar fusion for degenerative disk disease (DDD) is associated with variable clinical outcomes. Patients with workers' compensation claims often have worse fusion outcomes than the general population. Few studies have evaluated the risk factors for poor outcomes within this clinically distinct population. The goal of this study was to identify preoperative predictors of return to work status after fusion for DDD in a workers' compensation setting. The authors used International Classification of Diseases, Ninth Revision (ICD-9), diagnosis and Current Procedural Terminology (CPT) procedural codes to identify 1037 subjects from the Ohio Bureau of Workers' Compensation database who underwent fusion for DDD between 1993 and 2013. Of these subjects, 23.2% (n=241) made a sustained return to work within 2 years after fusion. To identify preoperative predictors of postoperative return to work status, the authors used multivariate logistic regression analysis, adjusting for many important covariates. These included prolonged time out of work (P<.001; odds ratio [OR], 0.24), psychiatric history (P<.001; OR, 0.14), prolonged use of opioid analgesics (P<.001; OR, 0.46), male sex (P=.014; OR, 0.65), and legal representation (P=.042; OR, 0.67). The return to work rates associated with these risk factors were 10.4%, 2.0%, 11.9%, 21.1%, and 20.7%, respectively. Of the study subjects, 76.8% (n=796) did not return to work and had considerably worse postoperative outcomes, highlighted by chronic opioid dependence and high rates of failed back syndrome, additional surgery, and new psychiatric comorbidity. The low return to work rates and other generally poor outcomes reported in this study may indicate a more limited role for lumbar fusion among patients with DDD who have workers' compensation claims. More studies are needed to determine whether fusion for DDD can improve function and quality of life in these patients.

Older Age and Leg Pain Are Good Predictors of Pain and Disability Outcomes in 2710 Patients Who Receive Lumbar Fusion

BACKGROUND

Identifying appropriate candidates for lumbar spine fusion is a challenging and controversial topic. The purpose of this study was to identify baseline characteristics related to poor/favorable outcomes at 1 year for a patient who received lumbar spine fusion.

QUESTIONS/PURPOSES

The aims of this study were to describe baseline characteristics of those who received lumbar surgery and to identify baseline characteristics from a spine repository that were related to poor and favorable pain and disability outcomes for patient who received lumbar fusion (with or without decompression), who were followed up for 1 full year and discriminate predictor variables that were either or in contrast to prognostic variables reported in the literature.

METHODS

This study analyzed data from 2710 patients who underwent lumbar spine fusion. All patient data was part of a multicenter, multi-national spine repository. Ten relatively commonly captured data variables were used as predictors for the study. Univariate/multivariate logistic regression analyses were run against outcome variables of pain/disability.

RESULTS

Multiple univariate findings were associated with pain/disability outcomes at 1 year including age, previous surgical history, baseline disability, baseline pain, baseline quality of life scores, and leg pain greater than back pain. Notably significant multivariate findings for both pain and disability include older age, previous surgical history, and baseline mental summary scores, disability, and pain.

CONCLUSION

Leg pain greater than back pain and older age may yield promising value when predicting positive outcomes. Other significant findings may yield less value since these findings are similar to those that are considered to be prognostic regardless of intervention type.

Psychological Predictors of Outcomes with Lumbar Spinal Fusion: A Systematic Literature Review

PURPOSE

To review the predictive/risk psychological factors at baseline that are associated with a favourable (or non-favourable) outcome following lumbar spinal fusion (LSF).

METHODS

A computer-assisted literature search of PubMed, CINAHL complete and EMBASE for studies published between January 1, 1990 and October 1, 2014 with controlled vocabulary and key words related to LSF, degenerative lumbar spine diagnoses and appropriate terms for predictive variables. Each study was required to be a retrospective or prospective design that involved LSF (all forms). Quality assessment was conducted with the Quality In Prognosis Studies tool. A study protocol was registered with the International Prospective Register of Systematic Reviews (PROSPERO# CRD42014008728).

RESULTS

The majority of the eight accepted studies were observational, prospective cohorts (n = 6). High levels of baseline depression and lower SF-36 Mental Component Scores (MCS) lower quality of life were associated with non-favourable outcomes. Two studies were rated as high quality, five were moderate and one study had low quality.

CONCLUSIONS

At present, there are a number of psychological variables that are associated with a poorer outcome with LSF. Higher levels of depression and lower scores on the SF-36 MCS are the most commonly implicated. However, based on the results of the studies using single arm designs there is not enough evidence to determine which psychological variables are influential in predicting outcomes for LSF. Copyright © 2015 John Wiley & Sons, Ltd.

Clinical depression is a strong predictor of poor lumbar fusion outcomes among workers' compensation subjects

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

Determine how psychosocial factors, particularly depression, impact lumbar fusion outcomes in a workers' compensation (WC) setting.

SUMMARY OF BACKGROUND DATA

WC patients are less likely to return to work (RTW) after fusion. Few studies evaluate risk factors within this clinically distinct population.

METHODS

A total of 2799 Ohio WC subjects were identified who underwent lumbar fusion between 1993 and 2013 using Current Procedural Terminology (CPT) procedural and International Classification of Diseases, Ninth Revision (ICD-9) diagnosis codes. A total of 123 subjects were diagnosed with depression before fusion. Subjects with a smoking history, prior lumbar surgery, permanent disability, and failed back syndrome were excluded. The primary outcome was whether subjects returned to work within 2 years of fusion and sustained this RTW for more than 6 months of the following year. To determine the impact depression had on RTW status, we performed a multivariate logistic regression analysis. We also compared time absent from work and other secondary outcomes using χ2 and t tests.

RESULTS

Subjects with preoperative depression had significantly higher rates of legal representation, degenerative lumbar disease, and higher medical costs, and used opioid analgesics for considerably longer before and after fusion (P<0.001).Depression group (10.6% [13/123]) and controls (33.0% [884/2676]) met our RTW criteria (P<0.001). Preoperative depression was a negative predictor of RTW status (P<0.001; odds ratio [OR]: 0.38). Additional predictors included working during same week as fusion (OR: 2.15), age more than 50 years (OR: 0.58), chronic preoperative opioid analgesia (OR: 0.58), and legal representation (OR: 0.64). After surgery, depression subjects were absent from work 184 more days compared with controls (P<0.001).

CONCLUSION

Overall, RTW rates after fusion were low, which was especially true for those with pre-existing depression. Depression was a strong negative predictor of postoperative RTW status. Psychological screening and treatment may be beneficial in these subjects. The poor outcomes in this study may highlight a more limited role for fusion among WC subjects with chronic low back pain where RTW is the treatment goal.

LEVEL OF EVIDENCE

3.