Low Back Pain

The pre-final standards, criteria, and rating system were pilot-tested by five authors (CB, CP, AC, HV, and LM) in a systematic review of PROMs measuring physical functioning in patients with low back pain [19 (link)] and in a systematic review of PROMs for hand osteoarthritis (manuscript in preparation). Issues that came up during the pilot test were discussed within the steering committee, resulting in final changes in the standards, criteria, and rating system. The rating system was also discussed with the chairman of the Dutch GRADE network. Finally, the “COSMIN Methodology for assessing the content validity of PROMs—user manual” was written, available from http://www.cosmin.nl.

In GBD 2017, as in previous GBDs, causes of mortality and morbidity are structured using a four-level classification hierarchy to produce results that are mutually exclusive and collectively exhaustive. GBD 2017 estimates 359 causes of DALYs, 77 of which are a source of disability but not a cause of death (eg, attention-deficit hyperactivity disorder, headache disorders, low back pain, and neck pain), and five of which are causes of death but not sources of morbidity (sudden infant death syndrome, aortic aneurysm, late maternal deaths, indirect maternal deaths, and maternal deaths aggravated by HIV/AIDS). In the GBD hierarchy, the number of mutually exclusive and collectively exhaustive fatal and non-fatal causes in each level for which GBD estimates is three at Level 1, 22 at Level 2, 169 at Level 3, and 293 at Level 4. The full GBD cause hierarchy, including corresponding International Classification of Diseases (ICD)-9 and ICD-10 codes and detailed cause-specific methods, is in GBD 2017 publications on cause-specific mortality11 and non-fatal health outcomes12 in the corresponding appendices.
GBD 2017 includes 195 countries and territories that are grouped into 21 regions on the basis of epidemiological similarities and geographical proximity.15 (link) For the purposes of statistical analyses, we further grouped regions into seven super-regions (central Europe, eastern Europe, and central Asia; high income; Latin America and Caribbean; north Africa and Middle East; south Asia; southeast Asia, east Asia and Oceania; and sub-Saharan Africa). Each year, GBD includes subnational analyses for a few new countries and continues to provide subnational estimates for countries that were added in previous cycles. Subnational estimation in GBD 2017 includes five new countries (Ethiopia, Iran, New Zealand, Norway, and Russia) and countries previously estimated at subnational levels (GBD 2013: China, Mexico, and the UK [regional level]; GBD 2015: Brazil, India, Japan, Kenya, South Africa, Sweden, and the USA; and GBD 2016: Indonesia and the UK [local government authority level]). All analyses are at the first level of administrative organisation within each country except for New Zealand (by Māori ethnicity), Sweden (by Stockholm and non-Stockholm), and the UK (by local government authorites). All subnational estimates for these countries were incorporated into model development and evaluation as part of GBD 2017. To meet data use requirements, we present all subnational estimates excluding those pending publication (Brazil, India, Japan, Kenya, Mexico, Sweden, the UK, and the USA); these results are presented in appendix tables and figures (appendix 2). Subnational estimates for countries with populations larger than 200 million people (as measured according to our most recent year of published estimates) that have not yet been published elsewhere are presented wherever estimates are illustrated with maps but are not included in data tables.

An electronic survey was used to gather information on weight and height in order to calculate each participant’s Body Mass Index (BMI). Climbing level for the last 12 months was collected and classified according to the recommendations of the IRCRA [18 (link)]. The prevalence of jumping descent in bouldering was recorded through questions designed by the authors.
The Nordic questionnaire of back pain [19 (link)], adjusted for sport specific settings [20 (link)], was used to examine the lifetime and one-year prevalence of thoracolumbar back pain as well as training volume of the participants. The Nordic questionnaire of back pain has shown acceptable test–retest reliability and validity to clinical examination [19 (link), 20 (link)]. Based on the sport adjusted Nordic questionnaire, questions focusing on training volume between 10 and 20 years of age were computed, since athletes are plausibly more susceptible to develop radiographic spinal changes of the spine during the growth spurt [13 (link), 21 (link)]. The Oswestry back pain disability index [22 (link)] was used to examine disability associated to thoracic and lumbar back pain.

During this background phase, the principal investigator (G.D.S.) and a research assistant (A.G.) reviewed literature and conducted a panel discussion with PCPs and communication experts (n = 5). Based on the findings from this stage, 4 clinical vignettes were developed. The vignettes described the following general medical diagnostic uncertainty scenarios: (1) enlarged lymph node in a patient with a history of lymphoma in remission (ie, worrisome for a recurrence), (2) new-onset headache, (3) fever and upper respiratory infection, and (4) subacute low back pain (eAppendix 2 in Supplement 1).

Following the institutional review board approval for the study (number: 119/2019; Muğla Sıtkı Koçman University Ethical Committee), a retrospective cohort analysis was performed using the medical records of patients. For the current study, patient consent is not required. All procedures executed involving human participants were in accordance with the ethical standards of the institutional ethical committee and with the 1964 Helsinki declaration.
A total of 146 patients who applied to the neurosurgery outpatient clinic with a recent abdominal CT (max three months) because of a lower back pain complaint were included in the study. Patients with a previous history of surgery or a vertebral fracture were excluded. After excluded patients, a total of 146 patients were included in the study, of whom 90 were female (61.6%) and 56 were male (38.4%). The mean age of the patients was 51.42±13.91 (20-82) years.
Lumbar vertebra CT scans of all patients were reviewed retrospectively. CT images at the level from L3-L4 intervertebral disc were analyzed for body composition of fat tissue and muscle mass volume through the dedicated CT software (Syngo.via, SOMATOM Definition Flash: Siemens Healthcare, Forchheim, Germany). The L3-L4 level was selected in sagittal reformat CT images with the software (Figure 1).
The density range of -200, -40 HU was selected for the fat density measurement in the cross-section with the "region grooving" application in the angled axial images obtained parallel to the disc plane at this level. First, the fat volume in the whole section was measured (visceral and subcutaneous). Then, only the visceral adipose tissue volume was calculated by drawing borders to exclude subcutaneous adipose tissue (Figure 2). The subcutaneous fat tissue volume was obtained by subtracting the visceral fat tissue volume from the total fat volume (Figure 3).
With the same application, muscle density was selected and paravertebral muscle tissue volume was calculated (bilateral musculus psoas major, musculus quadratus lumborum, musculus iliocostalis, musculus longissimus, musculus multifidus volumes). A Spearman correlation model was used to analyze visceral adiposity, subcutaneous fat, and muscle mass.
In CT images, each intervertebral disc space was evaluated in terms of the presence of osteophytes, loss of disc height, sclerosis in the end plates, and spinal stenosis (spinal canal narrowing under 15 mm AP diameter) to investigate the presence of degeneration. Each level was scored according to the presence of findings, with 1 point for the presence of osteophytes, loss of disc height, sclerosis in the end plates, and spinal stenosis. The total score at all levels (L1-S1) was calculated for each patient.
Statistical analyses were performed using IBM SPSS version 20.0 software (IBM Corp., Armonk, NY). The conformity of the data to normal distribution was assessed using the Shapiro-Wilk test. Normally distributed variables were presented as mean±standard deviation and those not showing normal distribution as median (minimum-maximum) values. Categorical variables were presented as numbers (n) and percentages (%). The Spearman's rank correlation coefficient test was used to determine the correlation between the measured parameters in various vertebral pathologies. Continuous variables were compared using the Mann-Whitney U test. The receiver operating characteristic (ROC) analysis was used to detect the area under the curve (AUC) and define the cutoff values with their sensitivities and specificities of the measurements. An alpha value of p<0.05 was accepted as statistically significant.