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Anaesthetists’ risk assessment of placebo nerve block studies using the SHAM (Serious Harm and Morbidity) scale
Author(s) -
Jarman J.,
Marks N.,
Fahy C.J.,
Costi D.,
Cyna A. M.
Publication year - 2012
Publication title -
anaesthesia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.839
H-Index - 117
eISSN - 1365-2044
pISSN - 0003-2409
DOI - 10.1111/j.1365-2044.2011.06998.x
Subject(s) - medicine , placebo , concordance , anesthesia , context (archaeology) , psychological intervention , psychiatry , alternative medicine , paleontology , pathology , biology
Summary The SHAM (Serious Harm and Morbidity) scale was developed to categorise the severity of potential complications of placebo control interventions in the context of local anaesthesia research. A convenience sample of 43 anaesthetists used the SHAM scale to grade ten published randomised controlled trials investigating local anaesthesia nerve blocks. The Fleiss κ statistic assessed agreement between these anaesthetists and probability of random agreement (Pr(e)) when using the SHAM scale; a κ > 0 shows concordance between assessors above random agreement. Overall κ was 0.50 (95% CI 0.49–0.51, p < 0.001), Pr(e) = 0.21. There was moderate agreement between assessors in determining whether studies were low‐risk (SHAM score 0–2) or high‐risk (SHAM score 3–4) (κ 0.60 (95% CI 0.58–0.62), Pr(e) = 0.51). Compared with anaesthetists given clinical examples of interventions when applying the SHAM score, anaesthetists who were not given examples showed significantly less inter‐individual agreement (κ 0.76 (95% CI 0.72–0.81), Pr(e) = 0.5 vs 0.45 (95% CI 0.41–0.49), Pr(e) = 0.52, p < 0.0001). These results suggest that the SHAM score can be successfully used to grade the severity of potential complications of placebo‐controlled interventions in local anaesthesia research and represent a first step towards the score’s validation.