|
Corticosteroid injections for lateral epicondylitis: a systematic overview |
Assendelft W J, Hay E M, Adshead R, Bouter L M |
|
|
Authors' objectives To assess the effectiveness of corticosteroid injections in the treatment of lateral epicondylitis.
Searching MEDLINE was searched from 1966 to 1994 and EMBASE from 1980 to 1994 using the subject headings and keywords 'epicondylitis', 'tenditis', 'elbow' and 'injection'.
Study selection Study designs of evaluations included in the reviewRandomised controlled trials (RCTs) were included.
Specific interventions included in the reviewCorticosteroid injections, using hydrocortisone, betamethasone or triamcinolone.
Participants included in the reviewPatients suffering from lateral epicondylitis. No other details (e.g. age, sex) of the participants in the individual primary studies are given, though it is stated that most studies were hospital-based, with patients referred by general practitioners.
Outcomes assessed in the reviewThe outcomes assessed by individual trials varied from visual analogue scales, to an assessor's rating of improvement in individual patients. These were transformed to a simple binary indicator of outcome, reflecting whether an individual trial showed that the treatment 'succeeded' or 'failed'. Adverse effects of treatment are also summarised.
How were decisions on the relevance of primary studies made?The authors do not state how the papers were selected for the review, or how many of the authors performed the selection.
Assessment of study quality RCTs were methodologically assessed using a 16-point checklist. This produced an overall methodological score for each trial, which was used to stratify the trials into high- and low-quality groups for the narrative review and meta-analysis. Independent assessment by two reviewers, with any disagreements resolved by a third reviewer.
Data extraction The authors do not state how the data were extracted for the review, or how many of the authors performed the data extraction.
Methods of synthesis How were the studies combined?Data on the main outcome from primary studies were combined to produce pooled odd ratios (ORs) for follow-up at 2 to 6 weeks, and more than 6 weeks, after randomisation. Studies were then stratified by methodological quality, and separate ORs were calculated for high- and low-quality studies. Adverse effects were described in a narrative review.
How were differences between studies investigated?A sensitivity analysis was carried out by calculating ORs separately for high- and low-quality trials. Statistical testing for heterogeneity also took place. Significant heterogeneity was found, which may have been due to variations in study quality, patient groups, and variation in the composition, number and interval of injections.
Results of the review Twelve trials with a total of 703 participants were included.
The pooled OR for short-term (2 to 6 weeks) improvement in outcome was 0.15 (95% confidence interval, CI: 0.10, 1.44), indicating a favourable effect of corticosteroids. For follow-up of more than 6 weeks, the OR was 0.73 (95% CI: 0.37, 0.23), indicating a lack of a long-term effect.
The sensitivity analysis found an OR for high-quality studies of only 0.14 (95% CI: 0.09, 0.23), compared to an OR of 0.49 for the lowest methodological quality studies (95% CI: 0.24, 1.02).
The summary OR was 0.20 (95% CI: 0.12, 0.35) for placebo-controlled studies, and 0.20 (95% CI: 0.11, 0.36) for 'pragmatic' studies, where the control group received some other treatment.
Authors' conclusions Corticosteroid injections seems to be safe and effective, but the evidence is inconclusive given the low methodological quality of many trials, the heterogeneity among them, and the fact that they were confined to a secondary care setting. Further trials are required (1) in a primary care setting, and (2) to determine optimum timing, dosage and injection timing, and technique.
CRD commentary The review is somewhat hampered by the lack of a meaningful outcome measure: it is uninformative to categorise trials simply according to whether they show successful or failed treatment. Firstly, this provides little information on the actual outcomes assessed within the individual trials. This is important as there seems to be heterogeneity in whether, and how, pain was measured; also, one study assessed improvement in symptoms and in grip. Secondly, in the absence of any consistent examination of outcomes assessed in individual trials, 'effectiveness' can only be summarised fairly crudely. The authors' comments on the limited generalisability of the results to general practice should be noted: as the participants were hospital-based and referred by general practitioners, there is a possibility of referral bias, i.e. the included patients may have been filtered on the basis of failure of prior treatment and chronicity of complaints. The authors' conclusions are, therefore, conservative but appropriate given the variation between the primary studies.
Bibliographic details Assendelft W J, Hay E M, Adshead R, Bouter L M. Corticosteroid injections for lateral epicondylitis: a systematic overview. British Journal of General Practice 1996; 46: 209-216 Indexing Status Subject indexing assigned by NLM MeSH Adrenal Cortex Hormones /adverse effects /therapeutic use; Humans; Injections, Intra-Articular; Randomized Controlled Trials as Topic; Statistics as Topic; Tennis Elbow /drug therapy AccessionNumber 11996008185 Date bibliographic record published 30/09/1996 Date abstract record published 30/09/1996 Record Status This is a critical abstract of a systematic review that meets the criteria for inclusion on DARE. Each critical abstract contains a brief summary of the review methods, results and conclusions followed by a detailed critical assessment on the reliability of the review and the conclusions drawn. |
|
|
|