Extracorporeal shock wave therapy, ultrasound-guided percutaneous lavage, corticosteroid injection and combined treatment for the treatment of rotator cuff calcific tendinopathy: a network meta-analysis of RCTs

To determine the validity of adjusted indirect comparisons by using data from published meta-analyses of randomised trials. Direct comparison of different interventions in randomised trials and adjusted indirect comparison in which two interventions were compared through their relative effect versus a common comparator. The discrepancy between the direct and adjusted indirect comparison was measured by the difference between the two estimates. Database of abstracts of reviews of effectiveness (1994-8), the Cochrane database of systematic reviews, Medline, and references of retrieved articles. 44 published meta-analyses (from 28 systematic reviews) provided sufficient data. In most cases, results of adjusted indirect comparisons were not significantly different from those of direct comparisons. A significant discrepancy (P<0.05) was observed in three of the 44 comparisons between the direct and the adjusted indirect estimates. There was a moderate agreement between the statistical conclusions from the direct and adjusted indirect comparisons (kappa 0.51). The direction of discrepancy between the two estimates was inconsistent. Adjusted indirect comparisons usually but not always agree with the results of head to head randomised trials. When there is no or insufficient direct evidence from randomised trials, the adjusted indirect comparison may provide useful or supplementary information on the relative efficacy of competing interventions. The validity of the adjusted indirect comparisons depends on the internal validity and similarity of the included trials.

To investigate discrepancies between direct comparison and adjusted indirect comparison in meta-analyses of new versus conventional pharmaceutical interventions. Results of direct comparison were compared with results of adjusted indirect comparison in three meta-analyses of new versus conventional drugs. The three case studies are (1) bupropion versus nicotine replacement therapy for smoking cessation, (2) risperidone versus haloperidol for schizophrenia, and (3) fluoxetine versus imipramine for depressive disorders. In all the three cases, effects of new drugs estimated by head-to-head trials tend to be greater than that by adjusted indirect comparisons. The observed discrepancies could not be satisfactorily explained by the play of chance or by bias and heterogeneity in adjusted indirect comparison. This observation, along with analysis of possible systematic bias in the direct comparisons, suggested that the indirect method might have produced less biased results. Simulations found that adjusted indirect comparison may counterbalance bias under certain circumstances. Adjusted indirect comparison could be used to cross-examine the validity and applicability of results from head-to-head randomized trials. The hypothesis that adjusted indirect comparison may provide less biased results than head-to-head randomized trials needs to be investigated by further research.

Extracorporeal shock wave therapy (ESWT) has been used to treat calcific tendonitis of the shoulder, but trials of ESWT for this purpose have had methodological deficiencies and thus there is limited evidence for its effectiveness. To determine whether fluoroscopy-guided ESWT improves function, reduces pain, and diminishes the size of calcific deposits in patients with chronic calcific tendonitis of the shoulder. Double-blind, randomized, placebo-controlled trial conducted between February 1997 and March 2001 among 144 patients (of 164 screened) recruited from referring primary care physicians, orthopedic surgeons, and sports physicians in 7 orthopedic departments in Germany and Austria. Either high-energy ESWT, low-energy ESWT, or placebo (sham treatment). The 2 ESWT groups received the same cumulative energy dose. Patients in all 3 groups received 2 treatment sessions approximately 2 weeks apart, followed by physical therapy. The primary end point was the change in the mean Constant and Murley Scale (CMS) score from baseline to 6 months after the intervention. Secondary end points were changes in the mean CMS scores at 3 and 12 months, as well as changes in self-rated pain and radiographic change in size of calcific deposits at 3, 6, and 12 months. Of 144 patients enrolled, all completed treatment as randomized and 134 completed the 6-month follow-up. Both high-energy and low-energy ESWT resulted in significant improvement in the 6-month mean (95% confidence interval [CI]) CMS score compared with sham treatment (high-energy ESWT: 31.0 [26.7-35.3] points; low-energy ESWT: 15.0 [10.2-19.8] points; sham treatment: 6.6 [1.4-11.8] points; P<.001 for both comparisons). Patients who received high-energy ESWT also had significant 6-month CMS improvements compared with those who received low-energy ESWT (P<.001). We found similar results for both the 3-month and 12-month CMS comparisons, as well as for self-rated pain and radiographic changes at 3, 6, and 12 months. Both high-energy and low-energy ESWT appeared to provide a beneficial effect on shoulder function, as well as on self-rated pain and diminished size of calcifications, compared with placebo. Furthermore, high-energy ESWT appeared to be superior to low-energy ESWT.