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Hafliðadóttir SH, Juhl CB, Nielsen SM, Henriksen M, Harris IA, Bliddal H, Christensen R. Placebo response and effect in randomized clinical trials: meta-research with focus on contextual effects. Trials 2021; 22:493. [PMID: 34311793 PMCID: PMC8314506 DOI: 10.1186/s13063-021-05454-8] [Citation(s) in RCA: 47] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Accepted: 07/13/2021] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Contextual effects (i.e., placebo response) refer to all health changes resulting from administering an apparently inactive treatment. In a randomized clinical trial (RCT), the overall treatment effect (i.e., the post-treatment effect in the intervention group) can be regarded as the true effect of the intervention plus the impact of contextual effects. This meta-research was conducted to examine the average proportion of the overall treatment effect attributable to contextual effects in RCTs across clinical conditions and treatments and explore whether it varies with trial contextual factors. METHODS Data was extracted from trials included in the main meta-analysis from the latest update of the Cochrane review on "Placebo interventions for all clinical conditions" (searched from 1966 to March 2008). Only RCTs reported in English having an experimental intervention group, a placebo comparator group, and a no-treatment control group were eligible. RESULTS In total, 186 trials (16,655 patients) were included. On average, 54% (0.54, 95%CI 0.46 to 0.64) of the overall treatment effect was attributable to contextual effects. The contextual effects were higher for trials with blinded outcome assessor and concealed allocation. The contextual effects appeared to increase proportional to the placebo effect, lower mean age, and proportion of females. CONCLUSION Approximately half of the overall treatment effect in RCTs seems attributable to contextual effects rather than to the specific effect of treatments. As the study did not include all important contextual factors (e.g., patient-provider interaction), the true proportion of contextual effects could differ from the study's results. However, contextual effects should be considered when assessing treatment effects in clinical practice. TRIAL REGISTRATION PROSPERO CRD42019130257 . Registered on April 19, 2019.
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Affiliation(s)
- Sigurlaug H Hafliðadóttir
- Section for Biostatistics and Evidence-Based Research, the Parker Institute, Bispebjerg and Frederiksberg Hospital, Nordre Fasanvej 57, DK-2000, Copenhagen F, Denmark.,SEARCH Research Group, Research Unit of Musculoskeletal Function and Physiotherapy, Institute of Sports Science and Clinical Biomechanics, Faculty of Health Sciences, University of Southern Denmark, Odense, Denmark
| | - Carsten B Juhl
- SEARCH Research Group, Research Unit of Musculoskeletal Function and Physiotherapy, Institute of Sports Science and Clinical Biomechanics, Faculty of Health Sciences, University of Southern Denmark, Odense, Denmark.,Department of Physiotherapy and Occupational Therapy, University Hospital of Copenhagen, Herlev, Gentofte, Denmark
| | - Sabrina M Nielsen
- Section for Biostatistics and Evidence-Based Research, the Parker Institute, Bispebjerg and Frederiksberg Hospital, Nordre Fasanvej 57, DK-2000, Copenhagen F, Denmark.,Research Unit of Rheumatology, Department of Clinical Research, University of Southern Denmark, Odense University Hospital, Odense, Denmark
| | - Marius Henriksen
- The Parker Institute, Copenhagen University Hospital Bispebjerg and Frederiksberg, Copenhagen, Denmark
| | - Ian A Harris
- Whitlam Orthopaedic Research Centre, Ingham Institute for Applied Medical Research, Sydney, New South Wales, Australia.,Faculty of Medicine, South Western Sydney Clinical School, The University of New South Wales, Sydney, New South Wales, Australia.,Institute of Musculoskeletal Health, School of Public Health, The University of Sydney, Sydney, New South Wales, Australia
| | - Henning Bliddal
- The Parker Institute, Copenhagen University Hospital Bispebjerg and Frederiksberg, Copenhagen, Denmark
| | - Robin Christensen
- Section for Biostatistics and Evidence-Based Research, the Parker Institute, Bispebjerg and Frederiksberg Hospital, Nordre Fasanvej 57, DK-2000, Copenhagen F, Denmark. .,Research Unit of Rheumatology, Department of Clinical Research, University of Southern Denmark, Odense University Hospital, Odense, Denmark.
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Mathur RK, Sahu K, Saraf S, Patheja P, Khan F, Gupta PK. Low-level laser therapy as an adjunct to conventional therapy in the treatment of diabetic foot ulcers. Lasers Med Sci 2016; 32:275-282. [DOI: 10.1007/s10103-016-2109-2] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Accepted: 11/14/2016] [Indexed: 12/26/2022]
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Figurová M, Ledecký V, Karasová M, Hluchý M, Trbolová A, Capík I, Horňák S, Reichel P, Bjordal JM, Gál P. Histological Assessment of a Combined Low-Level Laser/Light-Emitting Diode Therapy (685 nm/470 nm) for Sutured Skin Incisions in a Porcine Model: A Short Report. Photomed Laser Surg 2016; 34:53-5. [PMID: 26741109 DOI: 10.1089/pho.2015.4013] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
OBJECTIVE The aim of our study was to evaluate, from a histological point of view, the effect of photobiomodulation (PBM) with combined low-level laser therapy (LLLT)/light- emitting diode (LED) on porcine skin wound healing. BACKGROUND DATA Most LLLT/LED wound healing studies have been performed on various types of rat models, with their inherent limitations. Minipigs are evolutionary and physiologically closer to humans than rats. MATERIALS AND METHODS With the animals under general anesthesia, one full-thickness skin incision was performed on the back of each minipig (n = 10) and immediately closed using simple interrupted percutaneous sutures. The minipigs were randomly allocated into two groups: a PBM-treated group (LLLT λ = 685 nm, LED λ = 470 nm, both light sources producing power densities at 0.008 W/cm2; each light source delivering total daily doses of 3.36 J/cm2) and a sham-irradiated control group. Half of the animals in each group were killed on postoperative day 3, and the other half were killed on the postoperative day 7, and samples were removed for histological examination. RESULTS Combined red and blue PBM accelerated the process of re-epithelization and formation of cross-linked collagen fibers compared with sham irradiated control wounds. CONCLUSIONS Our results demonstrate that the current dose of combined red and blue PBM improves the healing of sutured skin incisions in minipigs.
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Affiliation(s)
- Mária Figurová
- 1 Department of Surgery, Orthopedics, Radiology, and Reproduction; Small Animal Clinic, University of Veterinary Medicine and Pharmacy , Košice, Slovak Republic
| | - Valent Ledecký
- 1 Department of Surgery, Orthopedics, Radiology, and Reproduction; Small Animal Clinic, University of Veterinary Medicine and Pharmacy , Košice, Slovak Republic
| | - Martina Karasová
- 1 Department of Surgery, Orthopedics, Radiology, and Reproduction; Small Animal Clinic, University of Veterinary Medicine and Pharmacy , Košice, Slovak Republic
| | - Marián Hluchý
- 1 Department of Surgery, Orthopedics, Radiology, and Reproduction; Small Animal Clinic, University of Veterinary Medicine and Pharmacy , Košice, Slovak Republic
| | - Alexandra Trbolová
- 1 Department of Surgery, Orthopedics, Radiology, and Reproduction; Small Animal Clinic, University of Veterinary Medicine and Pharmacy , Košice, Slovak Republic
| | - Igor Capík
- 1 Department of Surgery, Orthopedics, Radiology, and Reproduction; Small Animal Clinic, University of Veterinary Medicine and Pharmacy , Košice, Slovak Republic
| | - Slavomír Horňák
- 1 Department of Surgery, Orthopedics, Radiology, and Reproduction; Small Animal Clinic, University of Veterinary Medicine and Pharmacy , Košice, Slovak Republic
| | - Peter Reichel
- 2 Clinic for Swine, University of Veterinary Medicine and Pharmacy , Košice, Slovak Republic
| | - Jan M Bjordal
- 3 IGS, Physiotherapy Research Group, University of Bergen , Bergen, Norway
| | - Peter Gál
- 4 Department for Biomedical Research, East-Slovak Institute of Cardiovascular Diseases, Inc. , Košice, Slovak Republic.,5 Institute of Anatomy, 1st Faculty of Medicine, Charles University , Prague, Czech Republic .,6 Department of Pharmacology, Faculty of Medicine, Pavol Jozef Šafárik University , Košice, Slovak Republic.,7 Department of Pharmacognosy and Botany, Faculty of Pharmacy, Comenius University , Bratislava, Slovak Republic
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Beckmann KH, Meyer-Hamme G, Schröder S. Low level laser therapy for the treatment of diabetic foot ulcers: a critical survey. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE : ECAM 2014; 2014:626127. [PMID: 24744814 PMCID: PMC3976827 DOI: 10.1155/2014/626127] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 10/14/2013] [Revised: 01/10/2014] [Accepted: 01/19/2014] [Indexed: 12/17/2022]
Abstract
Diabetic foot ulcers as one of the most common complications of diabetes mellitus are defined as nonhealing or long-lasting chronic skin ulcers in diabetic patients. Multidisciplinary care for the diabetic foot is common, but treatment results are often unsatisfactory. Low level laser therapy (LLLT) on wound areas as well as on acupuncture points, as a noninvasive, pain-free method with minor side effects, has been considered as a possible treatment option for the diabetic foot syndrome. A systematic literature review identified 1764 articles on this topic. Finally, we adopted 22 eligible references; 8 of them were cell studies, 6 were animal studies, and 8 were clinical trials. Cell studies and animal studies gave evidence of cellular migration, viability, and proliferation of fibroblast cells, quicker reepithelization and reformed connective tissue, enhancement of microcirculation, and anti-inflammatory effects by inhibition of prostaglandine, interleukin, and cytokine as well as direct antibacterial effects by induction of reactive oxygen species (ROS). The transferral of these data into clinical medicine is under debate. The majority of clinical studies show a potential benefit of LLLT in wound healing of diabetic ulcers. But there are a lot of aspects in these studies limiting final evidence about the actual output of this kind of treatment method. In summary, all studies give enough evidence to continue research on laser therapy for diabetic ulcers, but clinical trials using human models do not provide sufficient evidence to establish the usefulness of LLLT as an effective tool in wound care regimes at present. Further well designed research trials are required to determine the true value of LLLT in routine wound care.
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Affiliation(s)
- Kathrin H Beckmann
- HanseMerkur Center for Traditional Chinese Medicine, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20246 Hamburg, Germany
| | - Gesa Meyer-Hamme
- HanseMerkur Center for Traditional Chinese Medicine, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20246 Hamburg, Germany
| | - Sven Schröder
- HanseMerkur Center for Traditional Chinese Medicine, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20246 Hamburg, Germany
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Chung H, Dai T, Sharma SK, Huang YY, Carroll JD, Hamblin MR. The nuts and bolts of low-level laser (light) therapy. J Periodontal Implant Sci 2011; 40:105-10. [PMID: 20607054 PMCID: PMC2895515 DOI: 10.5051/jpis.2010.40.3.105] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2010] [Accepted: 04/20/2010] [Indexed: 01/11/2023] Open
Abstract
Soon after the discovery of lasers in the 1960s it was realized that laser therapy had the potential to improve wound healing and reduce pain, inflammation and swelling. In recent years the field sometimes known as photobiomodulation has broadened to include light-emitting diodes and other light sources, and the range of wavelengths used now includes many in the red and near infrared. The term "low level laser therapy" or LLLT has become widely recognized and implies the existence of the biphasic dose response or the Arndt-Schulz curve. This review will cover the mechanisms of action of LLLT at a cellular and at a tissular level and will summarize the various light sources and principles of dosimetry that are employed in clinical practice. The range of diseases, injuries, and conditions that can be benefited by LLLT will be summarized with an emphasis on those that have reported randomized controlled clinical trials. Serious life-threatening diseases such as stroke, heart attack, spinal cord injury, and traumatic brain injury may soon be amenable to LLLT therapy.
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Affiliation(s)
- Hoon Chung
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA, USA
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Chung H, Dai T, Sharma SK, Huang YY, Carroll JD, Hamblin MR. The nuts and bolts of low-level laser (light) therapy. Ann Biomed Eng 2011; 40:516-33. [PMID: 22045511 DOI: 10.1007/s10439-011-0454-7] [Citation(s) in RCA: 808] [Impact Index Per Article: 62.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2011] [Accepted: 10/20/2011] [Indexed: 01/03/2023]
Abstract
Soon after the discovery of lasers in the 1960s it was realized that laser therapy had the potential to improve wound healing and reduce pain, inflammation and swelling. In recent years the field sometimes known as photobiomodulation has broadened to include light-emitting diodes and other light sources, and the range of wavelengths used now includes many in the red and near infrared. The term "low level laser therapy" or LLLT has become widely recognized and implies the existence of the biphasic dose response or the Arndt-Schulz curve. This review will cover the mechanisms of action of LLLT at a cellular and at a tissular level and will summarize the various light sources and principles of dosimetry that are employed in clinical practice. The range of diseases, injuries, and conditions that can be benefited by LLLT will be summarized with an emphasis on those that have reported randomized controlled clinical trials. Serious life-threatening diseases such as stroke, heart attack, spinal cord injury, and traumatic brain injury may soon be amenable to LLLT therapy.
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Affiliation(s)
- Hoon Chung
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA, USA
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Taradaj J, Franek A, Cierpka L, Brzezinska-Wcislo L, Blaszczak E, Polak A, Chmielewska D, Krol P, Dolibog P, Kucio C. Early and long-term results of physical methods in the treatment of venous leg ulcers: randomized controlled trial. Phlebology 2011; 26:237-45. [PMID: 21478141 DOI: 10.1258/phleb.2010.010048] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE To estimate early and long-term results of physical methods in the treatment of venous leg ulcers. METHOD In group A after surgical operation, 40 patients were treated with the high-voltage stimulation (HVS) (100 µs, 100 Hz, 100 V) and drug therapy. In group B after operation, 37 patients were treated with ultrasound (0.5 W/cm(2), 1 MHz) and drug therapy. In group C after operation, 33 patients were treated with low-level laser therapy (LLLT) (810 nm, 65 mW) and drug therapy. In group D after operation, 35 patients were treated with the compression stockings (25-31 mmHg) and drug therapy. In group E after operation, 37 patients were only treated with drug therapy. Group F consisted of 32 patients, conservatively treated with the HVS and drug therapy. Group G consisted of 20 patients, conservatively treated with ultrasound and drug therapy. Group H consisted of 21 patients, conservatively treated with LLLT and drug therapy. Group I consisted of 30 patients, conservatively treated with compression and drug therapy. Group J consisted of 27 patients only treated with drug therapy. RESULTS Both short and long term parameters showed that compression therapy is the most efficient in ulcer healing. The electrical and ultrasound methods are less effective. The laser therapy ared useless. CONCLUSION Superficial venous surgery in addition to compression therapy is the most efficient treatment of venous leg ulcers. The compression therapy should be continued both surgically and conservatively treated patients with healed ulcers. In special cases after superficial venous surgery (isolated superficial reflux) compression therapy could be applied only to the time of ulcer closure without continuing it longer. HVS and ultrasound therapy are useful methods in conservative treatment of venous leg ulcers. For surgically-treated patients these physical therapies are efficient only in superficial plus deep reflux cases. HVS and ultrasound can be alternative methods, but are less effective in recurrence risk. LLLT is not an efficient physical method in treatment of venous leg ulcers.
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Affiliation(s)
- J Taradaj
- Department of Medical Biophysics, Medical University of Silesia, ul. Medykow 18 budynek C2, 40-752 Katowice, Poland.
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Houreld N, Abrahamse H. Low-intensity laser irradiation stimulates wound healing in diabetic wounded fibroblast cells (WS1). Diabetes Technol Ther 2010; 12:971-8. [PMID: 21128844 DOI: 10.1089/dia.2010.0039] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
BACKGROUND Patients with diabetes suffer from slow-to-heal wounds, which often necessitate amputation. Low-intensity laser irradiation (LILI) has been shown to reduce the healing time in such patients. This study aimed to determine the effect of different wavelengths of LILI on cellular migration, viability, and proliferation in a wounded diabetic cell model. METHODS Diabetic wounded and unwounded human skin fibroblast cells (WS1) were irradiated at 632.8, 830, or 1,064 nm with 5 J/cm(2). Cellular morphology and migration were determined microscopically, while cellular viability was determined by ATP luminescence, and proliferation was determined by basic fibroblast growth factor expression and alkaline phosphatase activity. RESULTS Diabetic wounded cells irradiated at 1,064 nm showed a lesser degree of migration, viability, and proliferation compared to cells irradiated at 632.8 or 830 nm. Cells irradiated at 632.8 nm showed a higher degree of haptotaxis and migration as well as ATP luminescence compared to cells irradiated at 830 nm. CONCLUSIONS This study showed that LILI of diabetic wounded cells in the visible range (632.8 nm) was more beneficial to wound healing than irradiating the same cells to wavelengths in the infrared range. Cells irradiated at a longer wavelength of 1,064 nm performed worse.
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Affiliation(s)
- Nicolette Houreld
- Laser Research Centre, Faculty of Health Sciences, University of Johannesburg, Doornfontein, South Africa
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Abstract
BACKGROUND Placebo interventions are often claimed to substantially improve patient-reported and observer-reported outcomes in many clinical conditions, but most reports on effects of placebos are based on studies that have not randomised patients to placebo or no treatment. Two previous versions of this review from 2001 and 2004 found that placebo interventions in general did not have clinically important effects, but that there were possible beneficial effects on patient-reported outcomes, especially pain. Since then several relevant trials have been published. OBJECTIVES Our primary aims were to assess the effect of placebo interventions in general across all clinical conditions, and to investigate the effects of placebo interventions on specific clinical conditions. Our secondary aims were to assess whether the effect of placebo treatments differed for patient-reported and observer-reported outcomes, and to explore other reasons for variations in effect. SEARCH STRATEGY We searched the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library Issue 4, 2007), MEDLINE (1966 to March 2008), EMBASE (1980 to March 2008), PsycINFO (1887 to March 2008) and Biological Abstracts (1986 to March 2008). We contacted experts on placebo research, and read references in the included trials. SELECTION CRITERIA We included randomised placebo trials with a no-treatment control group investigating any health problem. DATA COLLECTION AND ANALYSIS Two authors independently assessed trial quality and extracted data. We contacted study authors for additional information. Trials with binary data were summarised using relative risk (a value of less than 1 indicates a beneficial effect of placebo), and trials with continuous outcomes were summarised using standardised mean difference (a negative value indicates a beneficial effect of placebo). MAIN RESULTS Outcome data were available in 202 out of 234 included trials, investigating 60 clinical conditions. We regarded the risk of bias as low in only 16 trials (8%), five of which had binary outcomes.In 44 studies with binary outcomes (6041 patients), there was moderate heterogeneity (P < 0.001; I(2) 45%) but no clear difference in effects between small and large trials (symmetrical funnel plot). The overall pooled effect of placebo was a relative risk of 0.93 (95% confidence interval (CI) 0.88 to 0.99). The pooled relative risk for patient-reported outcomes was 0.93 (95% CI 0.86 to 1.00) and for observer-reported outcomes 0.93 (95% CI 0.85 to 1.02). We found no statistically significant effect of placebo interventions in four clinical conditions that had been investigated in three trials or more: pain, nausea, smoking, and depression, but confidence intervals were wide. The effect on pain varied considerably, even among trials with low risk of bias.In 158 trials with continuous outcomes (10,525 patients), there was moderate heterogeneity (P < 0.001; I(2) 42%), and considerable variation in effects between small and large trials (asymmetrical funnel plot). It is therefore a questionable procedure to pool all the trials, and we did so mainly as a basis for exploring causes for heterogeneity. We found an overall effect of placebo treatments, standardised mean difference (SMD) -0.23 (95% CI -0.28 to -0.17). The SMD for patient-reported outcomes was -0.26 (95% CI -0.32 to -0.19), and for observer-reported outcomes, SMD -0.13 (95% CI -0.24 to -0.02). We found an effect on pain, SMD -0.28 (95% CI -0.36 to -0.19)); nausea, SMD -0.25 (-0.46 to -0.04)), asthma (-0.35 (-0.70 to -0.01)), and phobia (SMD -0.63 (95% CI -1.17 to -0.08)). The effect on pain was very variable, also among trials with low risk of bias. Four similarly-designed acupuncture trials conducted by an overlapping group of authors reported large effects (SMD -0.68 (-0.85 to -0.50)) whereas three other pain trials reported low or no effect (SMD -0.13 (-0.28 to 0.03)). The pooled effect on nausea was small, but consistent. The effects on phobia and asthma were very uncertain due to high risk of bias. There was no statistically significant effect of placebo interventions in the seven other clinical conditions investigated in three trials or more: smoking, dementia, depression, obesity, hypertension, insomnia and anxiety, but confidence intervals were wide.Meta-regression analyses showed that larger effects of placebo interventions were associated with physical placebo interventions (e.g. sham acupuncture), patient-involved outcomes (patient-reported outcomes and observer-reported outcomes involving patient cooperation), small trials, and trials with the explicit purpose of studying placebo. Larger effects of placebo were also found in trials that did not inform patients about the possible placebo intervention. AUTHORS' CONCLUSIONS We did not find that placebo interventions have important clinical effects in general. However, in certain settings placebo interventions can influence patient-reported outcomes, especially pain and nausea, though it is difficult to distinguish patient-reported effects of placebo from biased reporting. The effect on pain varied, even among trials with low risk of bias, from negligible to clinically important. Variations in the effect of placebo were partly explained by variations in how trials were conducted and how patients were informed.
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Affiliation(s)
- Asbjørn Hróbjartsson
- RigshospitaletThe Nordic Cochrane CentreBlegdamsvej 9, 3343CopenhagenDenmark2100
| | - Peter C Gøtzsche
- RigshospitaletThe Nordic Cochrane CentreBlegdamsvej 9, 3343CopenhagenDenmark2100
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Ferrer-del Castillo E, Pérez-Hernández J. Úlcera venosa crónica malignizada. Presentación de un caso. ANGIOLOGIA 2008. [DOI: 10.1016/s0003-3170(08)01009-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Banzer W, Hübscher M, Seib M, Vogt L. Short-Time Effects of Laser Needle Stimulation on the Peripheral Microcirculation Assessed by Laser Doppler Spectroscopy and Near-Infrared Spectroscopy. Photomed Laser Surg 2006; 24:575-80. [PMID: 17069486 DOI: 10.1089/pho.2006.24.575] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
OBJECTIVE The aim of the present study was to evaluate immediate effects of a standardized laser needle stimulation over a defined acupuncture point on the microvascular blood flow and muscle oxygenation in the human forearm. BACKGROUND DATA Recently, it has been shown that laser stimulation improves tissue perfusion. This is relevant since adequate blood supply is an important factor in the treatment of pain syndromes. METHODS The study was designed as a randomized, double-blinded, placebo-controlled trial. Thirty-three healthy non-smoking males were randomly assigned to a control group (n = 15) with no laser irradiation and to an intervention group (n = 18) for which laser needle irradiation was performed on the right forearm at acupuncture point Pe6. Non-invasive blood flow measurements (laser Doppler spectroscopy [LDS]) were performed before, during, and after intervention. Additionally, the dynamic changes in muscle oxygenation of the m. flexor carpi ulnaris were investigated using near-infrared spectroscopy (NIRS). RESULTS Repeated measures MANOVA demonstrated a statistically significant interaction between time and group (p = 0.034, effect size = 0.39), indicating that peripheral blood flow was influenced by laser needle application. In contrast, tissue oxygenation was not affected by the experimental treatment. CONCLUSION It has been demonstrated that laser needle stimulation may improve peripheral microcirculation under standardized conditions, whereas tissue oxygenation remained unchanged. Further research is required to determine the influence of various parameter settings and irradiation treatments on the peripheral microcirculation. Moreover, different acupuncture points should be investigated in order to appraise the clinical effectiveness of laserneedle stimulation.
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Affiliation(s)
- Winfried Banzer
- Department of Sports Medicine, Johann Wolfgang Goethe-University Frankfurt am Main, Frankfurt/Main, Germany.
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