Study	Reason for exclusion
Antonicelli 1991	Randomised study examining air filter in patients sensitive to house dust mite.
Bjornsdottir 2003	Study conducted in participants with rhinitis
Boquete 1997	Non‐randomised study.
Carter 2001	Randomised study on allergen avoidance. Excluded as pet ownership not specified as criterion for study entry. No skin prick tests were undertaken until completion of the study.
De Blay 2003	Randomised study assessing the effects of advice on mite allergen exposure reduction. This was excluded as it was a multiple treatment intervention.
Francis 2003	Randomised study assessing the effects of HEPA filter when compared with vacuum cleaner. This study was excluded as no placebo HEPA filter was included in the study.
Gore 2003	Before and after study.
Karlsson 2004	Scholl‐based study.
Reisman 1990	This randomised trial was conducted with patients who had an allergy to house dust mite.
Sabbah 2000	Review article.
van der Heide 1997	This randomised double‐blind study focused on participants with an allergic reaction to house dust mite allergen. Pet ownership was not an inclusion criteria, although in one third of the homes of participants, pets were resident. Pet allergic participants were included but only if they had an allergic reaction to house dust mite allergen.
Villaveces 1977	Double‐blind non‐randomised crossover study.