Odour detection in children and young people with profound intellectual and multiple disabilities.

Only 22 children completed the study, and they were selected by teachers or support workers from three special schools, so the group may not represent all children with PIMD. The study excluded children with food allergies or chronic airway problems needing daily respiratory therapy, so it does not show how those children respond. The study used one concentration for each odour, so it does not show how children respond to weaker or stronger odours. Prior odour experience was not controlled well; only 15 of 22 families returned familiarity ratings, and these were not used. The coding team included experimenters, and an experimenter-coder might remember which number matched which odour. The reflux and nausea questionnaires were recognised by speech therapists but had never been scientifically validated. The study measured short-term behavioural responses, not whether odour stimulation improves communication, feeding, mood, or daily function. Group analyses do not capture each child's individual pattern; one child's repeated nausea response to strawberry was an individual observation.

Do not read these behaviours as proof that odour stimulation helps children with PIMD. The study compared behaviour during odour and neutral presentations, not clinical outcomes. The repeated nausea response to strawberry was seen in one participant and cannot be treated as a general adverse effect.