Initially we screened the Cochrane Library database (http://www.thecochranelibrary.com
) for randomised controlled trial (RCT) data on treatments for ULDs likely to be administered by, or to influence the referral practices of primary care practitioners. We found Cochrane reports on four categories of treatment at the shoulder (steroid injections, acupuncture, physiotherapy, surgery vs. not surgery) [15
], four at the elbow (acupuncture, physiotherapy, surgery vs. not surgery, shockwave therapy) [19
], and three at wrist/hand (steroid injections, surgery vs. not surgery, other non-surgical interventions) [22
]. We listed all the primary research reports referenced in these reviews.
Additionally, as the searches underlying the Cochrane reviews were 2-8 years old and Cochrane reviews on certain treatments of interest (steroid injections and physiotherapy at the elbow) were planned but as yet unpublished, we updated all Cochrane searches to 30th
June 2010 and identified other non-Cochrane reviews on the two elbow treatments of interest. For these purposes, we searched in Medline and Embase (from the last relevant Cochrane search date to June 2010) and in Google Scholar (first 300 hits in March 2010), combining terms for ULD with those for randomised controlled trials (RCTs). After elimination of duplicate references, these searches yielded 156 potentially relevant papers from Cochrane reviews and 189 other potentially relevant titles (including several that were cited in four non-Cochrane reviews (on steroid injections [25
] and physiotherapy for epicondylitis [28
]) identified by the search.
We next excluded studies which: (1) lacked any ULD case definition; (2) did not allow analysis by anatomical site, or did not allow ULDs to be distinguished from neck problems; (3) did not report an outcome involving change in upper limb pain or function (or give enough information to quantify such an outcome); (4) had fewer than 10 subjects in a treatment arm (these were deemed to be at high potential for publication bias); (5) involved only select patient groups (e.g. stroke patients or victims of external trauma); (6) involved only a comparison between alternative surgical techniques or a choice of alternative oral drug therapies; (7) were not in English.
By these criteria, 160 (25 Cochrane-cited and 135 non-Cochrane cited) trial reports could be excluded by a review of their abstracts, while the remaining 185 RCT reports were retrieved for full inspection. lists the interventions considered by this report, the Cochrane and other reviews used as primary sources for the search (dates of currency and yield of papers), and the numbers of papers by source that were retrieved for full inspection.
Sources used to identify treatment trials of upper limb disorder
Retrieved reports were further screened to determine whether they supplied within-study estimates of treatment effect for more than one case definition (i.e. whether analyses were presented for subgroups of cases). Then, from the remainder, we excluded studies that were insufficiently similar in their main features ((i) anatomical site, (ii) intervention(s), (iii) comparison group, (iv) follow-up time, (v) outcome measure) to allow between-study comparison. Failure to match a study with at least one other study according to these criteria meant that informative comparison of effect sizes by case definitions could not be made.
In analysing responses to treatment we restricted attention to those that could be expressed as the prevalence of a binary outcome (e.g. cured/improved vs. not). We chose to omit continuous measures (e.g. change in mean pain score), since studies may have differed in their initial baseline distribution of values, leading to non-comparable potential for change. Decisions about the adequacy of matching and other exclusions were agreed in consensus by two of us (CHL and KTP).
For the finally included studies, note was made of the case definitions employed; and for all binary outcomes shared in common, the effect sizes (relative risks (RR)) with estimates of precision (95% confidence intervals (95%CI)) were recorded. Where RRs or their 95%CIs were not presented in the published reports, we estimated them from the numbers in each exposure-outcome combination, using the immediate command in STATA version 11 (StataCorp. 2009. Stata Statistical Software: Release 11. College Station, TX: StataCorp LP).
Comparisons of RR between paired case definitions were summarised by their ratios – taking the RR for the more complex and specific case definition (e.g. shoulder symptoms with signs) as the numerator and that for the simpler and broader case definition (e.g. shoulder symptoms) as the denominator. Where two definitions were equally complex, the numerator RR was chosen arbitrarily. 95% CIs for ratios of RRs were computed as the exponent of the confidence intervals of the difference between the logged RRs [29
]. Separate summary statistics were compiled by anatomical site and for each treatment-comparison combination.
Finally, to explore the possibility that the ratio of RRs might be biased towards unity where a treatment was ineffective (since RRs for both definitions and their ratio would all tend towards unity), in sensitivity analysis we restricted focus to those comparisons in which at least one of the paired RRs was ≥2 or ≤0.5.