Study	Reason for exclusion
Arlian 1999	Laboratory based controlled observation
Burr 2007	Randomised study of strategies to reduce indoor mould & complications of asthma. Humidification was not provided as standard across the intervention group
Cabrera 1995	Not a randomised controlled trial
Chivato 1997	Not a randomised controlled trial but an observational study.
Crane 1998	Not a randomised controlled trial.
Emenius 1993	Not a randomised controlled trial, observational study reported as an abstract.
Harving 1994	Not a randomised controlled trial.
Hyndman 2000	A randomised study where dehumidification has been used to control house dust mite. No patient outcomes have been studied.
Kercsmar 2006	Randomised study of numerous environmental remediation strategies to reduce indoor mould. Humidification was not provided as standard across the intervention group.
Korsgaard 1983	Not a randomised controlled trial
Morgan 2004	The focus of study was in the reduction of level of cockroach allergen & dust mite & complication of asthma. No outcome was recorded regarding dehumidification.
Mosbech 1988	Controlled study with no mention about randomisation.