Model validity of randomised placebo-controlled trials of individualised homeopathic treatment

Abstract

Purpose : A new programme of systematic reviews of randomised controlled trials (RCTs) of homeopathy distinguishes several key attributes of study design and quality: placebo controlled cf. other-than-placebo controlled; individualised cf. non-individualised homeopathy; treatment cf. prophylaxis; internal validity cf. model validity. The present phase of the review programme focuses on assessing the model validity (MV) of peer-reviewed, placebo-controlled, RCTs of individualised homeopathic treatment. Methods : A systematic literature search and subsequent reappraisal of retrieved records identified 31 RCTs that satisfied the inclusion criteria for the present study. MV of the eligible RCTs was appraised using a novel criterion-based method. Assessment domains address: (i) the rationale for the choice of the particular homeopathic intervention; (ii) the homeopathic principles reflected in the intervention; (iii) the extent of homeopathic practitioner input; (iv) the relevance of the main outcome measure; (v) the capability of the main outcome measure to detect change; (vi) the length of follow-up to the endpoint of the study. These six MV domains per RCT were categorised by each of three independent assessors as ?acceptable?, ?unclear? or ?unacceptable?, disparities of opinion being resolved by consensus discussion. Results : Domain-specific and overall ratings of MV per RCT await the outcome of ongoing consensus discussions. A full set of findings will be presented at conference. Conclusions : MV data contribute importantly to the appraisal of RCT quality in systematic reviews of homeopathy.

Model validity and risk of bias in randomised placebo-controlled trials of individualised homeopathic treatment

“…As previously reported, 3 there were 19 trials with acceptable MVHT, nine with uncertain MVHT, and four with inadequate MVHT (Table 2).…”

“…Those with 'high quality' are the three RCTs that comprise 'reliable evidence' based on RoB 2 and that also possess acceptable MVHT. 3 The main finding from our prior meta-analysis 2 has therefore not been modified by accommodating MVHT: there is cautious support for the hypothesis that the effect of the individualised homeopathic intervention is distinguishable from the same approach using placebos.…”

“…We previously applied the appraisal methods for RoB and for model validity of homeopathic treatment (MVHT), as described, 1,[3][4][5] to peer-reviewed papers that reported randomised placebo-controlled trials of individualised homeopathy, published up to the end of 2013. Through formal literature search methods, and after application of defined exclusion criteria, 31 papers (reporting a total of 32 RCTs) were found to be eligible for systematic review.…”

“…For each trial, the domains for MVHT assessment are summarised as follows 3,5 : Domain I (Rationale): Would a significant body of accredited homeopaths support the rationale for the intervention used in the study? Domain II (Principles): Is the specific intervention used consistent with homeopathic principles?…”

“…2 As regards MV of the same 32 RCTs, 19 were considered acceptable, nine uncertain, and four inadequate. 3 Sensitivity analysis reflecting the 'reliable evidence' produced cautious support for the hypothesis that the effect of the individualised homeopathic intervention is distinguishable from the same approach using placebos. 2 The purpose of the present paper is to merge together our previously published RoB and MV findings, 2,3 and, using an approach based on the GRADE method 4 to establish an overall quality designation for each of the 32 RCTs and to examine its impact on the sensitivity analysis findings.…”