Brehler 2006.

Methods	Randomised, placebo‐controlled, double‐blind, parallel‐group design
Participants	32 patients of mean age 37.2 years with proven sensitivity to house dust mite and symptoms of rhinoconjunctivitis
Interventions	House dust mite impermeable bedding
Outcomes	Symptom scores Use of anti‐allergic medication
Notes	—
Risk of bias
Bias	Authors' judgement	Support for judgement
Adequate sequence generation?	Unclear risk	"... the volunteers were randomised to receive either active or placebo encasings"
Allocation concealment?	Unclear risk	"... the covers for mattresses, pillows, and duvets or blankets were handed out in numbered packages"
Blinding?	Unclear risk	Insufficient information
Incomplete outcome data addressed? All outcomes	High risk	11 of the 32 patients enrolled did not complete the study; an intention‐to‐treat analysis was not undertaken
Free of selective reporting?	Low risk	—
Free of other bias?	High risk	The authors compared the outcome measures within the 2 arms not between them as required