Non-respondents do not bias outcome assessment after cervical spine surgery: a multicenter observational study from the Norwegian registry for spine surgery (NORspine).

BACKGROUND: The Norwegian registry for spine surgery (NORspine) is a national clinical quality registry which has recorded more than 10,000 operations for degenerative conditions of the cervical spine since 2012. Registries are large observational cohorts, at risk for attrition bias. We therefore aimed to examine whether clinical outcomes differed between respondents and non-respondents to standardized questionnaire-based 12-month follow-up. METHODS: All eight public and private providers of cervical spine surgery in Norway report to NORspine. We included 334 consecutive patients who were registered with surgical treatment of degenerative conditions in the cervical spine in 2018 and did a retrospective analysis of prospectively collected register data and data on non-respondents' outcomes collected by telephone interviews. The primary outcome measure was patient-reported change in arm pain assessed with the numeric rating scale (NRS). Secondary outcome measures were change in neck pain assessed with the NRS, change in health-related quality of life assessed with EuroQol 5 Dimensions (EQ-5D), and patients' perceived benefit of the operation assessed by the Global Perceived Effect (GPE) scale. RESULTS: At baseline, there were few and small differences between the 238 (71.3%) respondents and the 96 (28.7%) non-respondents. We reached 76 (79.2%) non-respondents by telephone, and 63 (65.6%) consented to an interview. There was no statistically significant difference between groups in change in NRS score for arm pain (3.26 (95% CI 2.84 to 3.69) points for respondents and 2.77 (1.92 to 3.63) points for telephone interviewees) or any of the secondary outcome measures. CONCLUSIONS: The results indicate that patients lost to follow-up were missing at random. Analyses of outcomes based on data from respondents can be considered representative for the complete register cohort, if patient characteristics associated with attrition are controlled for.

Comparing cost-effectiveness of X-Stop with minimally invasive decompression in lumbar spinal stenosis: a randomized controlled trial.

STUDY DESIGN: Randomized clinical trial with 2-year follow-up. OBJECTIVE: To compare the cost-effectiveness of X-stop to minimally invasive decompression in patients with symptomatic lumbar spinal stenosis. SUMMARY OF BACKGROUND DATA: Lumbar spinal stenosis is the most common indication for operative treatment in elderly. Although surgery is more costly than nonoperative treatment, health outcomes for more than 2 years were shown to be significantly better. Surgical treatment with minimally invasive decompression is widely used. X-stop is introduced as another minimally invasive technique showing good results compared with nonoperative treatment. METHODS: We enrolled 96 patients aged 50 to 85 years, with symptoms of neurogenic intermittent claudication within 250-m walking distance and 1- or 2-level lumbar spinal stenosis, randomized to either minimally invasive decompression or X-stop. Quality-adjusted life-years were based on EuroQol EQ-5D. The hospital unit costs were estimated by means of the top-down approach. Each cost unit was converted into a monetary value by dividing the overall cost by the amount of cost units produced. The analysis of costs and health outcomes is presented by the incremental cost-effectiveness ratio. RESULTS: The study was terminated after a midway interim analysis because of significantly higher reoperation rate in the X-stop group (33%). The incremental cost for X-stop compared with minimally invasive decompression was &OV0556;2832 (95% confidence interval: 1886-3778), whereas the incremental health gain was 0.11 quality-adjusted life-year (95% confidence interval: -0.01 to 0.23). Based on the incremental cost and effect, the incremental cost-effectiveness ratio was &OV0556;25,700. CONCLUSION: The majority of the bootstrap samples displayed in the northeast corner of the cost-effectiveness plane, giving a 50% likelihood that X-stop is cost-effective at the extra cost of &OV0556;25,700 (incremental cost-effectiveness ratio) for a quality-adjusted life-year. The significantly higher cost of X-stop is mainly due to implant cost and the significantly higher reoperation rate. LEVEL OF EVIDENCE: 2.

MRI evaluation of lumbar spinal stenosis: is a rapid visual assessment as good as area measurement?

BACKGROUND: Lumbar spinal stenosis (LSS) is commonly assessed on MRI by measuring dural sac cross-sectional area (DSCA). A new method, morphological grading A-D, has recently been introduced as an alternative method. OBJECTIVE: The aim of this study is to compare these two different methods for assessing LSS on MRI and study their reliability and intercorrelation. METHODS: On pretreatment MRI of 84 patients, two experienced radiologists independently classified level L2/L3, L3/L4 and L4/L5 as no, relative or significant stenosis using both methods. Agreement was analyzed by weighted Kappa. The correlation between the two methods was analysed using Spearman correlation, and visualized in a box plot. RESULTS: The interobserver agreement (95 % CI) was 0.69 (0.61-0.77) and 0.65 (0.56-0.74), respectively. The intraobserver agreements for DSCA were 0.77 (0.60-0.74) and 0.80 (0.66-0.93). On morphological grading A-D it was 0.78 (0.65-0.92) and 0.81 (0.68-0.94). The correlation coefficient between the two methods was 0.85 (p < 0.001). Grades C and D were under the limit value for significant stenosis using the DSCA. CONCLUSIONS: The study shows that the inter- and intraobserver agreements of DSCA and morphological grading A-D were acceptable and their intercorrelation is strong. Both methods may be used in the MRI evaluation of LSS.

Cost-effectiveness of total disc replacement versus multidisciplinary rehabilitation in patients with chronic low back pain: a Norwegian multicenter RCT.

STUDY DESIGN: Randomized clinical trial with 2-year follow-up. OBJECTIVE: To evaluate the cost-effectiveness of total disc replacement (TDR) versus multidisciplinary rehabilitation (MDR) in patients with chronic low back pain (CLBP). SUMMARY OF BACKGROUND DATA: The existing studies on CLBP report cost-effectiveness of fusion surgery versus disc replacement and fusion versus rehabilitation. This study evaluated the cost-effectiveness of TDR versus MDR. METHODS: Between April 2004 and May 2007, 173 patients with CLBP (>1 yr) were randomized to TDR (n = 86) or MDR (n = 87). Treatment effects (Euro Qol 5D [EQ-5D] and Short Form 6D [SF-6D]) and relevant direct and indirect costs at 6 weeks and at 3, 6, 12, and 24 months after treatment were assessed. Gain in quality-adjusted life years (QALYs) after 2 years was estimated. Cost-effectiveness was expressed as an incremental cost-effectiveness ratio. RESULTS: The mean QALYs gained (standard deviation) using EQ-5D was 1.29 (0.53) in the TDR group and 0.95 (0.52) in the MDR group, a significant difference of 0.34 (95% confidence interval 0.18-0.50). The mean total cost per patient in the TDR group was &OV0556;87,622 (58,351) compared with &OV0556;74,116 (58,237) in the MDR group, which was not significantly different (95% confidence interval: -4041 to 31,755). The incremental cost-effectiveness ratio for the TDR procedure varied from &OV0556;39,748 using EQ-5D (TDR cost-effective) to &OV0556;128,328 using SF-6D (TDR not cost-effective). The dropout rate was 20% (15% TDR group, 24% MDR group). Five patients moved from the MDR to the TDR group, whereas 9 patients randomized to TDR declined surgery. Using per-protocol analysis instead of intention-to-treat analysis indicated that TDR was not cost-effective, irrespective of the use of EQ-5D or SF-6D. CONCLUSION: In this study, TDR was cost-effective compared with MDR after 2 years when using EQ-5D for assessing QALYs gained and a willingness to pay of &OV0556;74,600 (kr500,000/QALY). TDR was not cost-effective when SF-6D was used; therefore, our results should be interpreted with caution. Longer follow-up is needed to accurately assess the cost-effectiveness of TDR. LEVEL OF EVIDENCE: 2.

Assessment of referrals to a multidisciplinary outpatient clinic for patients with back pain.

OBJECTIVE: Each year our multidisciplinary outpatient clinic for patients with back pain receives a large number of referrals from primary care physicians, manual physiotherapists, and chiropractors. We wanted to assess the quality of the referrals regarding the information provided about case history, clinical findings, and results from additional investigations. MATERIAL AND METHODS: Two hundred and eighty six consecutive referrals received in the time period from 1 October 2008 to 1 March 2009 were reviewed. We investigated if the referrals contained 12 given items. The items were defined by consensus of the broad range of specialists working at the multidisciplinary outpatient clinic. All registered items were regarded as useful when assigning patients with a priority and appropriate caregiver at the outpatient clinic. The 12 items that our group felt were reflective of good referrals were information about occupational status, duration of symptoms, pain distribution, sensory symptoms, use of analgesics, alleviating and/or aggravating factors, systems enquiry (i.e. urination, bowel movements, and sleep), provided treatment, deep tendon reflexes, motor function, sensory examination, and radiculopathy tests (i.e. straight leg raise and/or foraminal compression test). RESULTS: Two hundred and fifty six (89·5%) referrals were from primary care physicians, and the remaining came from physicians in internships, manual physiotherapists, and chiropractors. Six (2·1%) referrals contained all 12 items. On average each referral contained 5·95 items (95% CI: 5·66-6·25). Information about analgesics, sensory symptoms, systems enquiry, and alleviating and aggravating factors was most frequently missing. Information about provided treatment, motor function, deep tendon reflexes, clinical tests, and occupational status was included in about half of the referrals. In 27·3% of the referrals from primary care physicians information about clinical findings was missing. Referrals from manual physiotherapists contained statistically significant more information (9·67 items, 95% CI: 7·63-11·70) than from the other groups (P<0·001). The number of patients registered with each primary care physician did not affect the number of items in the referrals. CONCLUSION: Many of the referrals were inadequate. Inadequate referrals can lead to prolonged waiting time for examination and treatment. Referrals with relevant information about patient history and clinical findings are essential in order to assign patients with an appropriate caregiver at the outpatient clinic and to determine if and which diagnostic imaging findings are of clinical relevance.

Clinical outcomes and safety assessment in elderly patients undergoing decompressive laminectomy for lumbar spinal stenosis: a prospective study.

BACKGROUND: To assess safety, risk factors and clinical outcomes in elderly patients with spinal stenosis after decompressive laminectomy. METHODS: A prospective cohort of patients 70 years and older with spinal stenosis undergoing conventional laminectomy without fusion (n = 101) were consecutively enrolled from regular clinical practice and reassessed at 3 and 12 months. Primary outcome was change in health related quality of life measured (HRQL) with EuroQol-5 D (EQ-5D). Secondary outcomes were safety assessment, changes in Oswestry disability index (ODI), Visual Analogue Scale (EQ-VAS) score for self reported health, VAS score for leg and back pain and patient satisfaction. We used regression analyses to evaluate risk factors for less improvement. RESULTS: The mean EQ-5 D total score were 0.32, 0.63 and 0.60 at baseline, 3 months and 12 months respectively, and represents a statistically significant (P < 0.001) improvement. Effect size was > 0.8. Mean ODI score at baseline was 44.2, at 3 months 25.6 and at 27.9. This represents an improvement for all post-operative scores. A total of 18 (18.0%) complications were registered with 6 (6.0%) classified as major, including one perioperative death. Patients stating that the surgery had been beneficial at 3 months was 82 (89.1%) and at 12 months 73 (86.9%). The only predictor found was patients with longer duration of leg pain had less improvement in ODI (P < 0.001). Increased age or having complications did not predict a worse outcome in any of the outcome variables. CONCLUSIONS: Properly selected patients of 70 years and older can expect a clinical meaningful improvement of HRQL, functional status and pain after open laminectomy without fusion. The treatment seems to be safe. However, patients with longstanding leg-pain prior to operation are less likely to improve one year after surgery.

Health-related quality of life assessment by the EuroQol-5D can provide cost-utility data in the field of low-back surgery.

There is limited data on the cost-utility of low-back surgical procedures. The EuroQol-5D (EQ-5D) is a generic health-related quality of life (HRQL) instrument, which was designed for cost-utility analyses and for comparisons of therapeutic effects across different diseases. Disease-specific (HRQL) instruments cannot be used for such purposes. However, there is little evidence of the usefulness of the EQ-5D in the field of low-back surgery, and it might be too general to assess specific conditions. We therefore tested its validity and responsiveness against a widely used disease-specific HRQL instrument [the Oswestry disability index (ODI)], in a prospective study on 326 patients operated for degenerative disorders in the lumbar spine. The reliability of the EQ-5D was also evaluated. Follow-up time was 12 months. Cross-sectional construct validity of the EQ-5D and ODI in the assessments of pain, functional status, health state and employment status were equal. The ODI performed better only in the assessment of walking capability. Only small differences in responsiveness were found. The reliability of the EQ-5D was solid. Our results indicate that the EQ-5D is useful for estimating health state values and for monitoring outcome of patients undergoing low-back surgery. Hence, this instrument would provide valid data for cost-utility analyses.