Friday, June 2, 2023
| Study by first author | Year | Method score | Laser wavelength | Application technique | Result | Reason for exclusion |
|---|---|---|---|---|---|---|
| Mulcahy [40] | 1995 | 5 | 904 | Not stated | No significant differences between active and placebo LLLT | Does not satisfy control group criterion: Lacks sufficient patient numbers in placebo control group as only 3 patients had tendinopathy |
| Simunovic [41] | 1998 | 3 | 830 | Tendon + Trigger Points | LLLT significantly better than placebo | Does not satisfy criterion for specific endpoint and standard number of treatments: Only bilateral conditions were given placebo treatment, but data for this group were not presented |
| Vasseljen [42] | 1992 | 5 | 904 | Tendon | Traditional physiotherapy significantly better than LLLT | Does not satisfy blinding criterion: Neither therapist, patients or observers were blinded in the traditional physiotherapy group |
Randomised LLLT-trials Excluded for not Meeting Trial Design Criteria for Diagnosis, Blinding or Specific Endpoints
Trial characteristics by first author, method score, laser wavelength in nanometer, laser application technique, trial results and reason for exclusion.
| Study by first author | Method score | Wave-length | Application technique | Result | Reason for exclusion |
|---|---|---|---|---|---|
| Haker [43] | 6 | 904 | Tendon | No significant differences | Photograph in trial report shows that the laser probe was kept in skin contact and thereby violated the manufacturers' recommendation of a keeping the laser head at a distance of 10 cm. This violation caused a central blind spot of ca 3 cm2 which left the tendon pathology unexposed to LLLT (See Figure 2) |
| Siebert [44] | 6 | 904 + 632 | Tendon | No significant differences | Active laser treatment to the placebo group received red 632 nm LLLT, which we calculated to be (2.25J), which again is an adequate LLLT dose. Consequently this trials lacks a placebo or non-laser control group |
Randomised LLLT-trials Excluded for not Meeting Criteria of Valid Procedures for Active Laser and Placebo Laser Treatment
Trial characteristics given by first author, method score, laser wavelength, laser application technique, trial results and reason for exclusion.
| Study by first author | Method score | Patient numbers | Application technique | Control | Trial results |
|---|---|---|---|---|---|
| Basford [53] | 8 | 47 | Tendon | Placebo | 0 |
| Gudmundsen [51] | 6 | 92 | Tendon | Placebo | ++ |
| Haker [46] | 7 | 49 | Acupoints | Placebo | 0 |
| Haker [50] | 6 | 58 | Tendon | Placebo | + |
| Krashenninikoff [54] | 6 | 36 | Tendon | Placebo | 0 |
| Lam [55] | 7 | 37 | Tendon | Placebo | ++ |
| Løgdberg-Anderson [49] | 7 | 142 | Tendon | Placebo | ++ |
| Lundeberg [47] | 6 | 57 | Acupoints | Placebo | 0 |
| Oken [56] | 7 | 59 | Tendon | UL, Brace | ++ |
| Palmieri [57] | 6 | 30 | Tendon | Placebo | ++ |
| Papadoupolos [52] | 4 | 31 | Tendon | Placebo | - |
| Stergioulas [48] | 7 | 62 | Tendon | Placebo | ++ |
| Vasseljen [58] | 8 | 30 | Tendon | Placebo | + |
| Total | 6.5(Mean) | 730 |
Included Randomised LLLT-trials
Trial characteristics by first author, method score, laser application technique, control group type, trial results. The abbreviations used are determined by the following categories: (-) means a result in favour of the control group, (0) means a non-significant result, (+) means a positive result for LLLT in at least one outcome measure, and (++) means a consistent positive results for more than one outcome measure.
processing....
A literature search was performed on Medline, Embase, Cinahl, PedRo and the Cochrane Controlled Trial Register as advised by Dickersin et al.[35] for randomised controlled clinical trials. Key words were: Low level laser therapy OR low intensity laser therapy OR low energy laser therapy OR phototherapy OR HeNe laser OR IR laser OR GaAlAs OR GaAs OR diode laser OR NdYag, AND tendonitis OR lateral epicondylitis OR lateral epicondylopathy OR tennis elbow OR elbow tendonitis OR lateral epicondylalgia OR extensor carpi radialis tendonitis. Handsearching was also performed in national physiotherapy and medical journals from Norway, Denmark, Sweden, Holland, England, Canada and Australia. Additional information was gathered from researchers in the field.
The randomised controlled trials were subjected to the following seven inclusion criteria:
1) Diagnosis: Lateral elbow tendinopathy, operationalised as pain from the lateral elbow epicondyle upon finger or wrist extension
2) Treatment: LLLT with wavelengths in the range 632 – 1064 nm, irradiating either the tendon pathology, acupuncture points or trigger points
3) Design: Randomised parallel group design or crossover design
4) Blinding: Outcome assessors should be blinded
5) Control group: Placebo control groups or control groups receiving other non-laser interventions with at least 10 persons per group
6) Specific endpoints for pain intensity or global improvement of health measured within 1 – 52 weeks after inclusion.
Primary Outcome Measures. measured after the end of treatment, either as:
a) pain intensity on a 100 mm visual analogue scale (VAS) defined as the pooled estimate of the difference in change between the means of the treatment and the placebo control groups, weighted by the inverse of the pooled standard deviation of change for each study, i.e. weighted mean difference (WMD) of change between groups. The variance was calculated from the trial data and given as 95% confidence intervals [95% CI] in mm on VAS, or
b) improved global health status. This was defined as any one of the following categories: "improved", "good", "better", "much improved", "pain-free", "excellent". The numbers of "improved" patients were then pooled to calculate the relative risk for change in health status. A statistical software package (Revman 4.2) was used for calculations.
Secondary Outcome Measures. c) painfree grip strength (dynamometer, vigorimeter)
d) pain pressure threshold (algometer)
e) sick leave (days)
f) follow-up results at more than 1 week after the end of treatment for pain intensity (WMD) and/or improved global health status (RR) as described for the primary outcome measures
Due to possibility of measurement by different scales, the results for outcomes c) and d) are defined as the unitless pooled estimate of the difference in change between the mean of the treatment and the placebo control groups, weighted by the inverse of the pooled standard deviation of change for each study, i.e. standardised mean difference (SMD) of change between groups. The variance are calculated from the trial data and given as 95% confidence intervals.
Positive Bias Direction, Caused by Flaws in Trial Methodology, Funding Source. Trials were subjected to methodological assessments by the 10 point Delphi/PedRo checklists.[36] as trials of weaker methodology have been found to exaggerate results in a positive direction.[37] As profit funding has been shown to affect trial conclusions in a positive direction,[38] analysis of funding sources was also performed.
Negative Bias Direction, Caused by Poor Prognosis or Effective Co-interventions. LET patients with long symptom duration and high baseline pain intensity are found to have significantly poorer prognosis in a trial with symptom durations of 8 to 21 weeks.[2] Recent steroid injections have been reported to negatively affect prognosis in LET over a period of 3–12 months after injections.[6] Patient selection of known responders only has been shown to inflate trial results with 38%,[39] and consequently the inclusion of non-responders to treatments is likely to deflate effect sizes. Exercise therapy has been found effective in LET[13] and other tendinopathies,[17] and the use of exercise therapy as a co-intervention may also deflate effect sizes or erase positive effects of LLLT. Consequently, we decided to analyze the included trials for presence of long symptom duration, treatment and treatment failures prior to inclusion, and effective co-interventions.
