Swallowing Exercise During Head and Neck Cancer Treatment: Results of a Randomized Trial.

The sample size was based on fatigue for the resistance-training part of the intervention, not on the primary swallowing safety outcome. The control groups were not the same at both hospitals: one hospital used a non-active control and the other used an active occupational therapy exercise control. Separate hospital analyses found more benefits in the non-active control hospital, so those findings are not the primary comparison and may not be stable. Participants received both swallowing exercises and progressive resistance training, so the contribution of either component alone cannot be separated. Baseline radiotherapy dose differed between groups, with the intervention group receiving less total Gy. Follow-up was affected by deaths and loss to follow-up: 19 participants (8%) dropped out, 12 (5%) died and 2 (0.9%) were terminal at 12 months, and another 26 (11%) were lost to follow-up for other reasons. Analyses used complete cases and assumed data were missing at random. The primary swallowing safety assessment was not done at end of treatment or 6 months because fiberoptic endoscopic evaluation was too burdensome. Adherence to the swallowing intervention was analysed only in a sub-sample of 45 participants. The exercise programmes were individualised, which makes the intervention hard to compare with fixed exercise programmes in other studies. The study did not collect data on non-trial rehabilitation services or therapeutic interventions that could have affected outcomes.

Do not read the separate hospital analysis or the secondary mouth opening and symptom findings as proof that swallowing exercises improve aspiration safety. The primary swallowing safety outcome was null, and the intervention combined swallowing exercises with progressive resistance training, so the contribution of either component cannot be separated.