Influence of study design on outcomes following reflexology massage: an integrative and critical review of interventional studies

Background: Interpretation of the efficacy of reflexology is hindered by inconsistent research designs and complicated by professional views that RCT criteria are not ideal to research holistic CAM practice. The influence of research designs on study outcomes is not known. This integrative review sought to evaluate this possibility. Material and methods: 37 interventional studies (2000-2014) were identified that involved RCT or non-RCT design, and provided comparison of reflexology outcomes against a control/comparison group. Viability of integrating RCT and non-RCT studies into a single database was first evaluated by appraisal of 16 reporting fields related to study setting and objectives, sample demographics, methodological design, and treatment fidelity, and against Jadad-score quality criteria for RCTs. For appraisal the database was stratified into RCT/non-RCT or Jadad-score of 3+ or <3. Deficits in reporting were identified for blind assignment of participants, drop-out/completion rate and School of Reflexology. For comparison purposes, these fields were excluded from subsequent analysis for evidence of association between design fields and of fields with study outcomes. Results: 31 studies applied psychometric tools and 20 applied biometric tools (14 applied both). A total of 116 measures were utilised. Type of measure was associated with study objectives (p<0.001; chi square) in particular of psychometric measures with a collated ‘Behavioural/cognitive’ objective. Significant outcomes were more likely (p<0.001; chi square) for psychometric than biometric measures. Neither type of outcome was associated with choice of RCT or non-RCT methodology, but psychometric responses were associated (p=0.007) with a non-massage control strategy. Conclusions: The review provides support for psychometric responses to reflexology when study design utilises a non-massage control strategy. Findings suggest that an evaluation of outcomes against sham reflexology massage and other forms of massage, and a narrower focus of study objective, may clarify whether there is a relationship between study design and efficacy of reflexology.