Table 6 Quality items and scores of four studies using outcome measures in relation to somatosensory-evoked potentials included in a systematic review on the effect of spinal manipulation on ‘brain function’
1st Author Yr of publication Ref | -Were study subjects in sham controlled studies reported to be blind? (Yes / No / Unclear) -If yes / unclear, was the blinding tested for success? (Yes / No) -If yes, was it successful? (Yes / No) | -Were study subjects in studies with control group reported to be naive? (Yes / No / Unclear) -Was the origin of the subjects reported (Yes / No) -If yes, does it allow to exclude any interest? (Yes / No / Unclear) | Were study subjects reported to have been randomly allocated to study groups? (Yes / No / Unclear) | Were study groups comparable in relation to symptoms when studying symptomatic subjects (duration and pain intensity) (NA when cross-over study design)? (Yes / No) | Were the intervention and control(s) well described (at least where and how)? (Yes / No) | Was the assessor reported to be blind to group allocation? (Yes / No) | Were losses and exclusions of study subjects reported or obvious in result section (including in tables or graphs)? (Yes / No / Unclear) | Was the person who statistically analyzed the data reported to be blind to group allocation? (Yes / No) | Comments by the technical experts (i) on the statistical analysis, and (ii) in relation to the methodology and/or technical aspects |
|---|---|---|---|---|---|---|---|---|---|
Quality score (risk of bias, also including an external validity criteria) and classification | |||||||||
Haavik-Taylor 2007b [25] | -No -No -NA | 1: -No report of the testing of the normality of the data distribution. -To minimize Type 1 error, post hoc tests would be appropriate (instead of planned comparisons). -No between group comparison was performed. No expert was available in relation to the technical aspects of this outcome measure | |||||||
2/6 (33%) low | NA | =No 0 pt | Unclear ("pseudorandomized") 0.5pt | NA (SCP subjects) | -Yes 0.5pt -Yes 0.5pt | No (but data were coded by an independent person to reduce any bias during analysis) 0.5pt | No 0 pt | No 0 pt | |
Haavik-Taylor 2010a [26] | -No -No -NA | 1: Both parametric and nonparametric results on the same data are reported. Usually, either data are normally distributed and parametric tests can be used or data are not normally distributed and non-parametric tests must be used. No expert was available in relation to the technical aspects of this outcome measure | |||||||
2.5/6 (42%) medium | NA | = No 0 pt | Yes 1pt | NA (SCP subjects / cross-over) | -Yes 0.5 pt -Yes 0.5 pt | No (idem Haavik-Taylor 2007a) 0.5pt | No 0 pt | No 0 pt | |
Haavik-Taylor 2010b [21] | -No -Yes -Unclear (“students and staff population at the University of Auckland”) | 1: See comments in relation to Haavik-Taylor 2010a No expert was available in relation to the technical aspects of this outcome measure | |||||||
2.5/6 (42%) medium | NA | = No 0 pt | Yes 1 pt | NA (SCP subjects / cross-over) | -Yes 0.5 pt -Yes 0.5 pt | No (idem Haavik-Taylor 2007b) 0.5 pt | No 0 pt | No 0 pt | |
Lelic 2016 [14] | -Unclear (said to be naïve) -Yes -No (sham intervention was discovered as such by most of the subjects) | 1: Unusual reporting of statistics: no report of which were the experimental factors and how they were treated (but probably pre/post was treated within-subjects and interventions as between-subjects), and of the detailed results for the F tests of the ANOVA. No expert was available in relation to the technical aspects of this outcome measure | |||||||
2.5/6 (42%) medium | = No 0 pt | NA | Yes 1 pt | NA (SCP subjects / cross-over) | -Yes 0.5 pt -No 0 pt | No 0 pt | Yes 1 pt | No 0 pt |