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Yetişir A, Öztürk GY. Effects of low-level laser therapy on acupuncture points on knee pain and function in knee osteoarthritis. REVISTA DA ASSOCIACAO MEDICA BRASILEIRA (1992) 2023; 70:e20230264. [PMID: 38126411 PMCID: PMC10740188 DOI: 10.1590/1806-9282.20230264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Accepted: 06/03/2023] [Indexed: 12/23/2023]
Abstract
OBJECTIVE Knee osteoarthritis is a common and disabling disease. We aimed to examine the effect of low-level laser therapy in addition to routine physical therapy modalities (transcutaneous electrical stimulation, superficial heating modality of infrared, ultrasound, and exercise) on the functional status and pain in knee osteoarthritis. METHODS Patients with knee osteoarthritis (n=71) who underwent physical therapy (transcutaneous electrical stimulation, infrared, ultrasound, exercise therapy, and low-level laser therapy) were retrospectively screened. Patients who received low-level laser therapy on acupuncture points, transcutaneous electrical stimulation, infrared, ultrasound, and exercise were included in the low-level laser therapy (+) (n=35), and patients who received only transcutaneous electrical stimulation, ultrasound, infrared, and exercise were included in the low-level laser therapy (-) group (n=36). The Visual Analog Scale for activity pain, Lysholm Knee Scoring Scale, and walking and stair climbing tests were used before and after treatment obtained from patient files. RESULTS The post-treatment Visual Analog Scale activity score and walking and stair climbing test results were statistically significantly lower in the low-level laser therapy (+) group than in the low-level laser therapy (-) group. There was no significant difference in post-treatment Lysholm Knee Scoring Scale scores between the two groups. In both groups, the Visual Analog Scale activity, Lysholm Knee Scoring Scale, and walking and stair climbing test scores statistically significantly decreased after treatment. CONCLUSION Knee osteoarthritis increases with aging and creates significant functional limitations. low-level laser therapy with routine physiotherapy contributed to the improvement in the pain and functional status of the patients with knee osteoarthritis. Low-level laser therapy can be recommended in osteoarthritis treatment guidelines with the support of further studies, which is an easy-to-apply, effective, and reliable method.
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Affiliation(s)
- Ayşegül Yetişir
- Çukurova University, Faculty of Medicine, Department of Physical Medicine and Rehabilitation, Division of Rheumatology – Adana, Turkey
| | - Gülşah Yaşa Öztürk
- Adana City Training and Research Hospital, Department of Physical Medicine and Rehabilitation – Adana, Turkey
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Koevska V, Nikolic-Dimitrova E, Mitrevska B, Gjerakaroska-Savevska C, Gocevska M, Kalcovska B. Application of high-intensity laser in pain treatment of patients with knee osteoarthritis. Arch Public Health 2021. [DOI: 10.3889/aph.2021.6008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Osteoarthritis is a rheumatic disease characterized by degeneration and decay of cartilage in the joints. As the disease worsens, the joint space narrows causing numbness and pain, which often impairs movement. In addition to pharmacological therapy, low-intensity laser (LILT), high-intensity laser (HILT) and exercise are used to treat osteoarthritis (OA) of the knee. HILT is a new modality in our country and the experience from its application is small, especially in the treatment of OA of the knee. Aim of the paper was to compare the effect of HILT with LILT in the treatment of OA of the knee. Material and methods: This was a randomized comparative unilateral blind study involving 72 patients divided into two groups. The first group was treated with HILT, the second group treated with LILT. Outcome measure was the visual analogue scale (VAS) for pain, which was made on the first and tenth day of treatment. Statistical significance was defined as p <0.05. Results: We found a significant difference between the two groups in terms of VAS score after 10 therapies in favor to a significantly lower score, that is, less pain in the HILT group (p = 0.0035). The comparison of the VAS score between the two times in the two groups separately showed that in both, the HILT and the LILT groups, the VAS score after 10 days of therapy was significantly lower compared to thatat 0 time, for consequently p = 0.00001vsp = 0.00001. Conclusion: Treatment with HILT and LILT significantly reduces pain and stiffness in patients with OA. Patients treated with HILT had better results, i.e., had a significant reduction in pain than patients treated with LILT. HILT was more effective than LILT.
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Liao FY, Lin CL, Lo SF, Chang CC, Liao WY, Chou LW. Efficacy of Acupoints Dual-Frequency Low-Level Laser Therapy on Knee Osteoarthritis. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE : ECAM 2020; 2020:6979105. [PMID: 33029170 PMCID: PMC7532399 DOI: 10.1155/2020/6979105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Revised: 07/30/2020] [Accepted: 08/04/2020] [Indexed: 11/18/2022]
Abstract
BACKGROUND Knee osteoarthritis (OA) presented with knee pain and limitation of mobility is common, and it may become a chronic problem resulting in major loss of function, with related impaired activity of daily living. Current traditional therapy for knee OA includes pharmacological treatment and physiotherapy, but the efficacies are limited. An alternative noninvasive treatment low-level laser therapy (LLLT) applied to acupoints is still contradictory and the efficacy needs to be assessed. METHODS AND MATERIALS We conduct the randomized double-blind control study to investigate the efficacy of a dual-frequency LLLT (combines red light (780 nm) and near-infrared light (830 nm)) in patients suffering knee OA. Participates were randomly assigned into active laser therapy (ALT) and placebo laser therapy (PLT) groups. Subjects in the ALT group were separately treated by laser apparatus at the three acupoints (SP9, SP10, and EX-LE2) on their knee joints under continuous radiation for 15 min at the maximum intensity, three times per week for four weeks. The PLT group used laser apparatus of the same model according to similar procedures without laser light emission. Outcome Measurements including visual analog scale (VAS), pain pressure threshold (PPT), and Lequesne index were used. RESULTS A total of 30 subjects with two-sided knee OA in both groups completed the experiment. Statistically significant decreases were observed in the Lequesne index (5.27 ± 3.26 vs. 10.83 ± 3.83), conscious VAS 4 weeks after treatment (moving: 2.87 ± 1.13 vs. 5.67 ± 1.72; resting: 0.33 ± 0.62 vs. 2.67 ± 1.29), and the increase was noted in PPT (21.23 ± 1.82 kg vs. 13.02 ± 1.46 kg) in the ALT group compared with the PLT group. CONCLUSION It appears that the knee OA pain and disability can be decreased after a dual-frequency LLLT applied to acupoints (SP9, SP10, and EX-LE2). The clinical efficacy of LLLT is highly related to the therapeutic settings of the laser apparatus; hence, more clinical trials with diffident parameter settings are needed to be further clarified.
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Affiliation(s)
- Fang-Yin Liao
- Department of Physical Medicine and Rehabilitation, China Medical University Hospital, Taichung 40432, Taiwan
| | - Chien-Lin Lin
- Department of Physical Medicine and Rehabilitation, China Medical University Hospital, Taichung 40432, Taiwan
- School of Chinese Medicine, College of Chinese Medicine, China Medical University, Taichung 40433, Taiwan
| | - Sui-Foon Lo
- Department of Physical Medicine and Rehabilitation, China Medical University Hospital, Taichung 40432, Taiwan
- School of Chinese Medicine, College of Chinese Medicine, China Medical University, Taichung 40433, Taiwan
| | - Chun-Ching Chang
- Department of Rehabilitation, New Bodhi Hospital, Taichung 41222, Taiwan
| | - Wen-Yen Liao
- Department of Physical Medicine and Rehabilitation, China Medical University Hospital, Taichung 40432, Taiwan
| | - Li-Wei Chou
- Department of Physical Medicine and Rehabilitation, China Medical University Hospital, Taichung 40432, Taiwan
- Department of Physical Therapy and Graduate Institute of Rehabilitation Science, China Medical University, Taichung 40433, Taiwan
- Department of Physical Medicine and Rehabilitation, Asia University Hospital, Asia University, Taichung 41350, Taiwan
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Ailioaie LM, Litscher G. Molecular and Cellular Mechanisms of Arthritis in Children and Adults: New Perspectives on Applied Photobiomodulation. Int J Mol Sci 2020; 21:E6565. [PMID: 32911717 PMCID: PMC7554967 DOI: 10.3390/ijms21186565] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 08/31/2020] [Accepted: 09/02/2020] [Indexed: 12/13/2022] Open
Abstract
Juvenile idiopathic arthritis and adult rheumatoid arthritis are two major groups with chronic joint pain and inflammation, extra-articular manifestations, and high risk of comorbidities, which can cause physical and ocular disability, as well as create great socio-economic pressure worldwide. The pathogenesis of arthritis manifested in childhood and adulthood is multifactorial, unclear, and overly complex, in which immunity plays an important role. Although there are more and more biological agents with different mechanisms of action for the treatment of arthritis, the results are not as expected, because there are partial responses or non-responsive patients to these compounds, high therapeutic costs, side effects, and so on; therefore, we must turn our attention to other therapeutic modalities. Updating knowledge on molecular and cellular mechanisms in the comparative pathogenesis of chronic arthritis in both children and adults is necessary in the early and correct approach to treatment. Photobiomodulation (PBM) represents a good option, offering cost-effective advantages over drug therapy, with a quicker, more positive response to treatment and no side effects. The successful management of PBM in arthritis is based on the clinician's ability to evaluate correctly the inflammatory status of the patient, to seek the optimal solution, to choose the best technology with the best physical parameters, and to select the mode of action to target very precisely the immune system and the molecular signaling pathways at the molecular level with the exact amount of quantum light energy in order to obtain the desired immune modulation and the remission of the disease. Light is a very powerful tool in medicine because it can simultaneously target many cascades of immune system activation in comparison with drugs, so PBM can perform very delicate tasks inside our cells to modulate cellular dysfunctions, helping to initiate self-organization phenomena and finally, healing the disease. Interdisciplinary teams should work diligently to meet these needs by also using single-cell imaging devices for multispectral laser photobiomodulation on immune cells.
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Affiliation(s)
- Laura Marinela Ailioaie
- Department of Medical Physics, Alexandru Ioan Cuza University, 11 Carol I Boulevard, 700506 Iaşi, Romania;
- Ultramedical & Laser Clinic, 83 Arcu Street, 700135 Iaşi, Romania
| | - Gerhard Litscher
- Research Unit of Biomedical Engineering in Anesthesia and Intensive Care Medicine, Research Unit for Complementary and Integrative Laser Medicine, and Traditional Chinese Medicine (TCM) Research Center Graz, Medical University of Graz, Auenbruggerplatz 39, 8036 Graz, Austria
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Sardim AC, Prado RP, Pinfildi CE. Efeito da fotobiomodulação associada a exercícios na dor e na funcionalidade de pacientes com osteoartrite de joelho: estudo-piloto. FISIOTERAPIA E PESQUISA 2020. [DOI: 10.1590/1809-2950/18020027022020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
RESUMO O objetivo do estudo foi avaliar o efeito da fotobiomodulação associada a exercícios na dor e na funcionalidade de pacientes com osteoartrite de joelho. Para isso foram recrutados 20 pacientes com osteoartrite do joelho uni ou bilateral, que foram distribuídos em dois grupos: grupo-controle (GC), que realizou aplicação de fotobiomodulação (FBM) placebo e um protocolo de exercício; e grupo fotobiomodulação (GF), que realizou aplicação ativa da FBM e o protocolo de exercício, sendo esse realizado duas vezes por semana durante oito semanas e consistindo de alongamentos passivos dos músculos de membros inferiores, straight leg raise, treinamento proprioceptivo e exercícios para o controle da marcha. A FBM foi aplicada com o aparelho cluster contendo quatro diodos de 670 nm e cinco diodos de 850 nm, com uma potência de saída de 540 mW, sendo a dose utilizada de 4 J/cm2. Os grupos foram avaliados pré e pós-tratamento com os questionários SF-36, Lequesne, Tinetti, e por meio da Escala Visual Analógica de dor (EVA). Os dados foram analisados com o método Anova, seguido do Bonferroni. Os dados indicaram melhoras significativas para o GF ao fim do tratamento para as avaliações da EVA (2±1,25 vs. 0,7±0,82; p=0,009). Embora ambos os grupos tenham obtido melhoras significativas ao longo do tratamento, não foi possível observar diferenças significativas entre eles para o restante das avaliações ao final do tratamento. Portanto, conclui-se que o uso da FBM associada a exercícios apresentou melhora da dor nos pacientes com osteoartrite de joelho, embora não tenha sido possível observar diferenças significativas no que diz respeito à funcionalidade.
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Fangel R, Vendrusculo-Fangel LM, Albuquerque CPD, Parizotto NA, Paz CCDSC, Matheus JPC. Low level laser therapy for reducing pain in rheumatoid arthritis and osteoarthritis: a systematic review. FISIOTERAPIA EM MOVIMENTO 2019. [DOI: 10.1590/1980-5918.032.ao29] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Abstract Introduction: Treatments for rheumatoid arthritis (RA) and osteoarthritis (OA) can reduce, modulate inflammation, and reduce deformities. Low-Level Laser Therapy is a biomodulator and may aid in the clinical picture of these conditions. Objective: To analyze the parameters most frequently used to determine the responses of patients with RA and OA in controlled and uncontrolled clinical trials. Method: This is a systematic review with search of articles in English, Portuguese and Spanish in PUBMED, SCOPUS, LILACS and Web of SCIENCE, of articles published between 2006 and 2018. MeSH terms were used. Inclusion criteria: evaluation of LLLT in the evaluations, evaluation and evaluation of the period, controlled and uncontrolled clinical trials, full publications. The base date of the energy dosimetry and the analysis of mean, median and mode of energy per point and energy per treatment. Results: Three articles on RA and 16 on OA were included in this study. Regarding dosimetry, it was one of the most recent of the pain, being this one with a greater energy dose. In OA, most of the articles presented are of importance, with variability in the dosage applied. Conclusion: There are several reports for patient studies purposes, mainly with doses of 6 J per point and 48 J. In the joints affected with OA and AR, it would be important to publish more scientific articles with better methodological quality and description of dosimetry.
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Affiliation(s)
- Renan Fangel
- Centro Universitário EuroAmericano, Brazil; Universidade de Brasília, Brazil
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White PF, Elvir Lazo OL, Galeas L, Cao X. Use of electroanalgesia and laser therapies as alternatives to opioids for acute and chronic pain management. F1000Res 2017; 6:2161. [PMID: 29333260 PMCID: PMC5749131 DOI: 10.12688/f1000research.12324.1] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 12/11/2017] [Indexed: 12/28/2022] Open
Abstract
The use of opioid analgesics for postoperative pain management has contributed to the global opioid epidemic. It was recently reported that prescription opioid analgesic use often continued after major joint replacement surgery even though patients were no longer experiencing joint pain. The use of epidural local analgesia for perioperative pain management was not found to be protective against persistent opioid use in a large cohort of opioid-naïve patients undergoing abdominal surgery. In a retrospective study involving over 390,000 outpatients more than 66 years of age who underwent minor ambulatory surgery procedures, patients receiving a prescription opioid analgesic within 7 days of discharge were 44% more likely to continue using opioids 1 year after surgery. In a review of 11 million patients undergoing elective surgery from 2002 to 2011, both opioid overdoses and opioid dependence were found to be increasing over time. Opioid-dependent surgical patients were more likely to experience postoperative pulmonary complications, require longer hospital stays, and increase costs to the health-care system. The Centers for Disease Control and Prevention emphasized the importance of finding alternatives to opioid medication for treating pain. In the new clinical practice guidelines for back pain, the authors endorsed the use of non-pharmacologic therapies. However, one of the more widely used non-pharmacologic treatments for chronic pain (namely radiofrequency ablation therapy) was recently reported to have no clinical benefit. Therefore, this clinical commentary will review evidence in the peer-reviewed literature supporting the use of electroanalgesia and laser therapies for treating acute pain, cervical (neck) pain, low back pain, persistent post-surgical pain after spine surgery (“failed back syndrome”), major joint replacements, and abdominal surgery as well as other common chronic pain syndromes (for example, myofascial pain, peripheral neuropathic pain, fibromyalgia, degenerative joint disease/osteoarthritis, and migraine headaches).
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Affiliation(s)
- Paul F White
- P.O. Box 548, Gualala, CA 95445, USA.,The White Mountain Institute, The Sea Ranch, CA, USA.,Department of Anesthesiology, Cedars-Sinai Medical Center, 8700 Beverly Boulevard, Los Angeles, CA 95445, USA
| | - Ofelia Loani Elvir Lazo
- Department of Anesthesiology, Cedars-Sinai Medical Center, 8700 Beverly Boulevard, Los Angeles, CA 95445, USA
| | | | - Xuezhao Cao
- Department of Anesthesiology, Cedars-Sinai Medical Center, 8700 Beverly Boulevard, Los Angeles, CA 95445, USA.,First Hospital of China Medical University, Shenyang, China
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Treatment of drug-resistant fibromyalgia symptoms using high-intensity laser therapy: a case-based review. Rheumatol Int 2017; 38:517-523. [PMID: 29080932 DOI: 10.1007/s00296-017-3856-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Accepted: 10/13/2017] [Indexed: 12/11/2022]
Abstract
Fibromyalgia is a chronic musculoskeletal condition characterized by widespread pain in the body and is associated with tender points at the shoulder, back and hip regions. A wide variety of pharmacologic drugs and dietary supplements have been used with limited success in treating the musculoskeletal pain. Early clinical studies with low level laser therapy (LLLT) alone or in combination with drugs commonly used to treat fibromyalgia suggested that LLLT may be effective in reducing musculoskeletal pain and stiffness, as well as the number of tender locations. However, a sham-controlled study reported that LLLT was not significantly better than the sham treatment and kinesiotape. Preliminary studies with high-intensity laser therapy (HILT) suggest that it may be more effective than LLLT for treating chronic pain syndromes. Therefore, we evaluated low (1 W), intermediate (42 W) and high level (75 W) HILT in a woman with long-standing fibromyalgia syndrome which was resistant to both standard pharmacotherapy and treatment in an interdisciplinary pain management program. The patient received a series of treatments with a HILT device (Phoenix Thera-lase) at a wavelength of 1275 nm administered at both the paraspinous region and tender points in the shoulder and hip regions. Although the 1 W treatment produced minimal symptom relief, both the 42 and the 75 W treatments produced a dramatic reduction in her overall pain, improved quality of sleep, and increased her level of physical activity for 4-10 days after these treatment sessions. This case illustrates the potential beneficial effects of using higher power levels of HILT for patients with fibromyalgia syndrome who have failed to respond to conventional interdisciplinary treatment regimens.
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Milares LP, Assis L, Siqueira A, Claudino V, Domingos H, Almeida T, Tim C, Renno AC. Effectiveness of an aquatic exercise program and low-level laser therapy on articular cartilage in an experimental model of osteoarthritis in rats. Connect Tissue Res 2016; 57:398-407. [PMID: 27220395 DOI: 10.1080/03008207.2016.1193174] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE The aim of this study was to evaluate the effects of an aquatic exercise program and low-level laser therapy (LLLT) (associated or not) on degenerative modifications and inflammatory mediators on the articular cartilage using an experimental model of knee OA. METHOD Forty male Wistar rats were divided into 4 groups: knee OA - without treatment (OA); OA plus exercise program group (OAE); OA plus LLLT (OAL); OA plus exercise program associated with LLLT (OAEL). Trained rats performed a water-jumping program carrying a load equivalent to 50-80 % of their body mass strapped to their chest. The laser irradiation was used either as the only method or after the exercise training had been performed, at 2 points contact mode (medial and lateral side of the left joint). The treatments started 4 weeks after the surgery, 3 days/week for 8 weeks. RESULTS The results revealed that all treated groups (irradiated or not) exhibited a better pattern of tissue organization, with less fibrillation and irregularities along the articular surface and improved chondrocytes organization. Also, a lower cellular density and structural damage (OARSI score) and higher thickness values were observed in all treated groups. Additionally, OAE and OAEL showed a reduced expression in IL-1β and caspase-3 as compared with OA. Furthermore, a statistically lower MMP-13 expression was only observed in OAEL as compared with OA. CONCLUSION These results suggest that aquatic exercise program and LLLT were effective in preventing cartilage degeneration. Also, physical exercise program presented anti-inflammatory effects in the knees in OA rats.
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Affiliation(s)
- Luiz Paulo Milares
- a Department of Bioscience , Federal University of São Paulo , Santos , Brazil
| | - Lívia Assis
- a Department of Bioscience , Federal University of São Paulo , Santos , Brazil
| | - Amanda Siqueira
- a Department of Bioscience , Federal University of São Paulo , Santos , Brazil
| | - Vitoria Claudino
- a Department of Bioscience , Federal University of São Paulo , Santos , Brazil
| | - Heloisa Domingos
- a Department of Bioscience , Federal University of São Paulo , Santos , Brazil
| | - Thais Almeida
- a Department of Bioscience , Federal University of São Paulo , Santos , Brazil
| | - Carla Tim
- a Department of Bioscience , Federal University of São Paulo , Santos , Brazil
| | - Ana Claudia Renno
- a Department of Bioscience , Federal University of São Paulo , Santos , Brazil
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Heller GZ, Manuguerra M, Chow R. How to analyze the Visual Analogue Scale: Myths, truths and clinical relevance. Scand J Pain 2016; 13:67-75. [PMID: 28850536 DOI: 10.1016/j.sjpain.2016.06.012] [Citation(s) in RCA: 282] [Impact Index Per Article: 35.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Revised: 06/07/2016] [Accepted: 06/30/2016] [Indexed: 01/17/2023]
Abstract
BACKGROUND AND AIMS The Visual Analogue Scale (VAS) is a popular tool for the measurement of pain. A variety of statistical methods are employed for its analysis as an outcome measure, not all of them optimal or appropriate. An issue which has attracted much discussion in the literature is whether VAS is at a ratio or ordinal level of measurement. This decision has an influence on the appropriate method of analysis. The aim of this article is to provide an overview of current practice in the analysis of VAS scores, to propose a method of analysis which avoids the shortcomings of more traditional approaches, and to provide best practice recommendations for the analysis of VAS scores. METHODS We report on the current usage of statistical methods, which fall broadly into two categories: those that assume a probability distribution for VAS, and those that do not. We give an overview of these methods, and propose continuous ordinal regression, an extension of current ordinal regression methodology, which is appropriate for VAS at an ordinal level of measurement. We demonstrate the analysis of a published data set using a variety of methods, and use simulation to compare the power of the various methods to detect treatment differences, in differing pain situations. RESULTS We demonstrate that continuous ordinal regression provides the most powerful statistical analysis under a variety of conditions. CONCLUSIONS AND IMPLICATIONS We recommend that in the situation in which no covariates besides treatment group are included in the analysis, distribution-free methods (Wilcoxon, Mann-Whitney) be used, as their power is indistinguishable from that of the proposed method. In the situation in which there are covariates which affect VAS, the proposed method is optimal. However, in this case, if the VAS scores are not concentrated around either extreme of the scale, normal-distribution methods (t-test, linear regression) are almost as powerful, and are recommended as a pragmatic choice. In the case of small sample size and VAS skewed to either extreme of the scale, the proposed method has vastly superior power to other methods.
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Affiliation(s)
- Gillian Z Heller
- Department of Statistics, Faculty of Science and Engineering, Macquarie University, NSW, 2109, Australia
| | - Maurizio Manuguerra
- Department of Statistics, Faculty of Science and Engineering, Macquarie University, NSW, 2109, Australia
| | - Roberta Chow
- Brain and Mind Centre, 94 Mallett Street, Camperdown, NSW 2050, Australia
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