Comparing pain intensity rating scales in acute postoperative pain: boundary values and category disagreements.

Pain intensity assessment scales are important in evaluating postoperative pain and guiding management. Different scales can be used for patients to self-report their pain, but research determining cut points between mild, moderate and severe pain has been limited to studies with < 1500 patients. We examined 13,017 simultaneous acute postoperative pain ratings from 913 patients taken at rest and on activity, between 4 h and 48 h following surgery using both a verbal rating scale (no, mild, moderate or severe pain) and 0-100 mm visual analogue scale. We determined the best cut points on the visual analogue scale between mild and moderate pain as 35 mm, and moderate and severe pain as 80 mm. These remained consistent for pain at rest and on activity, and over time. We also explored the presence of category disagreements, defined as patients verbally describing no or mild pain scored above the mild/moderate cut point on the visual analogue scale, and patients verbally describing moderate or severe pain scored below the mild/moderate cut point on the visual analogue scale. Using 30 and 60 mm cut points, 1533 observations (12%) showed a category disagreement and using 35 and 80 mm cut points, 1632 (13%) showed a category disagreement. Around 1 in 8 simultaneous pain scores implausibly disagreed, possibly resulting in incorrect pain reporting. The reasons are not known but low rates of literacy and numeracy may be contributing factors. Understanding these disagreements between pain scales is important for pain research and medical practice.

Validity of outcome measures used in randomized clinical trials and observational studies in degenerative lumbar spinal stenosis.

It is unclear whether outcome measures used in degenerative lumbar spinal stenosis (DLSS) have been validated for this condition. Cross-sectional analysis of studies for DLSS included in systematic reviews (SA) and meta-analyses (MA) indexed in the Cochrane Library. We extracted all outcome measures for pain and disability. We assessed whether the studies provided external references for the validity of the outcome measures and the quality of the validation studies. Out of 20 SA/MA, 95 primary studies used 242 outcome measures for pain and/or disability. Most commonly used were the VAS (n = 69), the Oswestry Disability Index (n = 53) and the Zurich Claudication Questionnaire (n = 22). Although validation references were provided in 45 (47.3%) primary studies, only 14 validation studies for 9 measures (disability n = 7, pain and disability combined n = 2) were specifically validated in a DLSS population. The quality of the validation studies was mainly poor. The Zurich Claudication Questionnaire was the only disease specific tool with adequate validation for assessing treatment response in DLSS. To compare results from clinical studies, outcome measures need to be validated in a disease specific population. The quality of validation studies need to be improved and the validity in studies adequately cited.

Association between depression and anxiety on symptom and function after surgery for lumbar spinal stenosis.

Evidence on the role of depression and anxiety in patients undergoing surgical treatment for symptomatic degenerative lumbar spinal stenosis (DLSS) is conflicting. We aimed to assess the association between depression and anxiety with symptoms and function in patients undergoing surgery for DLSS. Included were patients with symptomatic DLSS participating in a prospective multicentre cohort study who underwent surgery and completed the 24-month follow-up. We used the hospital anxiety and depression scale (HADS) to assess depression/anxiety. We used mixed-effects models to quantify the impact on the primary outcome change in the spinal stenosis measure (SSM) symptoms/function subscale from baseline to 12- and 24-months. Logistic regression analysis was used to quantify the odds of the SSM to reach a minimal clinically important difference (MCID) at 24 months follow-up. The robustness of the results in the presence of unmeasured confounding was quantified using a benchmarking method based on a multiple linear model. Out of 401 patients 72 (17.95%) were depressed and 80 anxious (19.05%). Depression was associated with more symptoms (ß = 0.36, 95% confidence interval (CI) 0.20 to 0.51, p < 0.001) and worse function (ß = 0.37, 95% CI 0.24 to 0.50, p < 0.001) at 12- and 24-months. Only the association between baseline depression and SSM symptoms/function was robust at 12 and 24 months. There was no evidence for baseline depression/anxiety decreasing odds for a MCID in SSM symptoms and function over time. In patients undergoing surgery for symptomatic DLSS, preoperative depression but not anxiety was associated with more severe symptoms and disability at 12 and 24 months.

Trends and regional variation in vertebroplasty and kyphoplasty in Switzerland: a population-based small area analysis.

Regional variation in procedure use often reflects the uncertainty about the risks and benefit of procedures. In Switzerland, regional variation in vertebroplasty and balloon kyphoplasty rates was high, although the variation declined between 2013 and 2018. Substantial parts of the variation remained unexplained, and likely signal unequal access and differing physician opinion. PURPOSE: To assess trends and regional variation in percutaneous vertebroplasty (VP) and balloon kyphoplasty (BKP) use across Switzerland. METHODS: We conducted a population-based analysis using patient discharge data from all Swiss acute care hospitals for 2013-2018. We calculated age/sex-standardized mean procedure rates and measures of variation across VP/BKP-specific hospital areas (HSAs). We assessed the influence of potential determinants of variation using multilevel regression models with incremental adjustment for demographics, cultural/socioeconomic, health, and supply factors. RESULTS: We analyzed 7855 discharges with VP/BKP from 31 HSAs. The mean age/sex-standardized procedure rate increased from 16 to 20/100,000 persons from 2013 to 2018. While the variation in procedure rates across HSAs declined, the overall variation remained high (systematic component of variation from 56.8 to 6.9 from 2013 to 2018). Determinants explained 52% of the variation. CONCLUSIONS: VP/BKP procedure rates increased and regional variation across Switzerland declined but remained at a high level. A substantial part of the regional variation remained unexplained by potential determinants of variation.

[Pain medications for acute and chronic low back pain]. / Medikamentöse Therapie bei akuten und chronischen lumbalen Rückenschmerzen.

Low back pain is common. In the acute (duration <6 weeks) and subacute pain phases (6-12 weeks) the main goal of pharmacological pain treatment is to enable patients to move and to stay as active as possible. In the chronic phase, pain medications can support non-pharmacological measures and improve physical function. Although almost every person will experience low back pain at least once in a lifetime, for many pain medications no clinical studies on their efficacy exist. Most data are available on the efficacy of non-steroidal anti-inflammatory drugs (NSAIDs) in acute and chronic low back pain; however, potential adverse effects and contraindications for NSAIDs need to be taken into account when the medication is prescribed. For other non-opioid medications (e. g. paracetamol, metamizole) the efficacy is not well studied. Weak and strong opioids have been shown to be effective compared to placebo in the short term; however, there is increasing evidence that opioids are no more effective than non-opioid medications in the treatment of acute and chronic low back pain. Furthermore, gastrointestinal and central nervous system adverse effects of opioids should be considered. Conclusion: in low back pain, the choice of a specific pain medications is based on the individual patient preferences, contraindications, and potential adverse effects. The main goal of pain medications is to enable patients to stay active. In persisting pain, non-pharmacological measures are important and should complement pharmacological pain treatment.

Painful swelling after a noxious event and the development of complex regional pain syndrome 1: A one-year prospective study.

BACKGROUND: The timing of diagnosis of complex regional pain syndrome (CRPS) 1 remains a challenge due to the large heterogeneity of clinical presentations. We describe the distribution and differences in outcomes and clinical manifestations between time points and patient groups with and without CRPS 1 following an initiating event. METHODS: Prospective cohort study with a consecutive registration of patients presenting with painful swelling of the affected extremity after an initiating event and follow-up visits after 3, 6 and 12 months. RESULTS: Forty-two patients were enrolled (37 females, mean age 55.1 years). At baseline, 35 participants (83%, females n = 30) fulfilled the diagnostic criteria for CRPS 1. At 3 months, 19 out of the initial 35 CRPS 1 patients (54%) did not meet the diagnostic criteria anymore. Besides our inclusion criteria of a painful swelling, early manifestations indicating a CRPS 1 primarily include an impaired quality of life (SF-35, EQ5-D), more pain (NRS, MPQ) and restricted range of motion. CONCLUSIONS: CRPS 1 develops within 8 weeks following a noxious event. Although many CRPS 1 patients reach partial remission within the first 3 months, signs and symptoms do not improve significantly at 1 year. In order to identify prognostic risk factors large prospective cohort studies are needed. SIGNIFICANCE: This prospective cohort study follows patients with complaints most suspected for complex regional pain syndrome (CRPS) 1. CRPS 1 develops within 8 weeks following a noxious event. Although many CRPS 1 patients reach partial remission within the 3 months, symptoms do not improve significantly at 1 year.