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Sex differences in pain perception are known to exist; however, the exact pathomechanism remains unclear. This work aims to elucidate sex differences in subjective and objective measures of pain, functional impairment, and health-related quality of life (HRQoL) in patients with lumbar degenerative disc disease. In a prospective 2-center study, back and leg pain (visual analogue scale [VAS]), functional disability (Oswestry Disability Index and Roland-Morris Disability Index), and HRQoL (EuroQol-5D and Short Form [SF12]) were collected for consecutive patients undergoing lumbar spine surgery. Objective functional impairment (OFI) was estimated using age-adjusted and sex-adjusted cutoff values for the timed-up-and-go (TUG) test. A healthy cohort of n = 110 subjects served as the control group. Univariate and multivariate analyses were performed to test the association between sex and pain, subjective and OFIs, and HRQoL. The study comprised n = 305 patients (41.6% females). Female patients had more VAS back pain (P = 0.002) and leg pain (P = 0.014). They were more likely to report higher functional impairment in terms of Oswestry Disability Index (P = 0.005). Similarly, HRQoL measured with the EuroQol-5D index (P = 0.012) and SF12 physical composite score (P = 0.005) was lower in female patients. Female patients reported higher VAS back and leg pain, functional impairment, and reduced HRQoL than male patients. However, there were no sex differences with respect to the presence and degree of OFI measured by the TUG test using age-adjusted and sex-adjusted cutoff values. As such, the TUG may be a good test to overcome sex bias for the clinical assessment of patients with degenerative disc disease.

Chronic low back pain (CLBP) is one of the most common, poorly understood, and potentially disabling chronic pain conditions from which older adults suffer. Many older adults remain quite functional despite CLBP, and because age-related comorbidities often exist independently of pain (e.g., medical illnesses, sleep disturbance, mobility difficulty), the unique impact of CLBP is unknown. We conducted this research to identify the multidimensional factors that distinguish independent community dwelling older adults with CLBP from those that are pain-free. Three hundred twenty cognitively intact participants (162 with moderate pain for 3 months, and 158 pain-free) underwent comprehensive assessment of pain severity, medical comorbidity (illnesses, body mass index, medications), severity of degenerative disc and facet disease, lumbar flexion, psychological constructs (self-efficacy, mood, overall mental health), and self-reported as well as performance-based physical function. Significant differences were ascertained for all 22 measures. Discriminant function analysis revealed that eight measures uniquely maximized the separation between the two groups (self-reported function with the Functional Status Index and the SF-36, performance-based function with repetitive trunk rotation and functional reach, mood with the Geriatric Depression Scale, comorbidity with the Cumulative Illness Rating Scale and BMI, and severity of degenerative disc disease). These results should help to guide investigators that perform studies of CLBP in older adults and practitioners that want an easily adaptable battery for use in clinical settings.

Prior studies evaluating predictors of pain-related outcomes following treatment for sciatica have been limited by methodological problems, including retrospective study design, use of unvalidated outcome measures, and short-term follow-up periods. Despite these limitations, some reports have suggested that symptoms of psychological distress may predict individual differences in pain treatment-related outcomes (e.g., higher levels of depressive and anxious symptomatology are associated with greater pain and disability after treatment). In this study, we sought to determine whether acute symptoms of depression and anxiety were prospectively associated with treatment outcomes over a 3-year follow-up period in surgically treated and non-surgically treated patients with sciatica. Patients were recruited from the practices of community-based physicians throughout the state of Maine, and underwent in-person baseline assessments, with mailed follow-up questionnaires at 3, 6, 12, 24, and 36 months. Study outcomes included patient-reported symptoms of pain and disability. For each outcome variable, we examined whether baseline mood (i.e., mood assessed prior to the initiation of treatment), as well as mood at the immediately preceding assessment point, prospectively predicted outcomes over 3 years in multivariate repeated-measures analyses. In most analyses, symptoms of depression and anxiety, both at baseline and at the preceding time point, were significant independent predictors of worse pain and function after controlling for relevant covariates. Collectively, elevated distress appears to be a significant risk factor for reduced treatment benefit (i.e., less improvement in pain and disability) over short and medium-term follow-up periods in patients with sciatica. Future research should determine whether the prospective identification and treatment of patients with high levels of distress (a "yellow flag") is associated with improved treatment outcomes.

In a prospective controlled trial on 46 patients undergoing lumbar discectomy, three classes of variables (medical data including MRI-identified morphological abnormalities, general psychological factors and psychosocial aspects of work) were analyzed with regard to their predictive value for the outcome of lumbar disc surgery at 2 year follow-up. Multiple regression analyses were used to identify the best predictor variables of four different outcome measures (i.e. pain relief, reduction of disability in daily activities, return to work and surgical outcome). MRI-identified nerve root compromise and social support from the spouse were independent predictors of pain relief 2 years after surgery (R2 = 0.40, P < 0.01). Return to work 2 years after surgery was best predicted by depression and occupational mental stress (R2 = 0.36, P < 0.001). MRI-identified extent of herniation and depression were significant predictors of a good surgical outcome after lumbar discectomy (R2 = 0.61, P < 0.001). This study has demonstrated that the outcome of discectomy is critically dependent on which outcome variables are selected and that different sorts of predictor variables have a distinct influence on the various outcome variables. Obvious morphological alterations (i.e. disc extrusions, nerve root compromise) proved to be significant predictors of postoperative pain relief and improvement of disability in daily activities justifying a surgical treatment approach in these cases. The most important finding of this study was that return to work was not influenced by any clinical findings or MR-identified morphological alterations, but solely by psychological factors (i.e. depression) and psychological aspects of work (i.e. occupational mental stress).