Maximising response to postal questionnaires – A systematic review of randomised trials in health research

Table 2 Quality assessment scores of included studies

Author	Random-isation performed?	Allocation concealed?	Similar baseline characteristics?	Eligibility criteria specified?	Blind outcome assessment?	Adequate reporting of results?	ITT analysis?	No performance bias?	Quality score
Dorman 1997	√	?	√	√	?	√	?	√	A
Dunn 2003	√	?	√	√	√	X	√	√	A
Evans 2004	√	?	√	√	?	X	?	√	B
Iglesias 2000	√	√	√	X	√	√	√	√	A
Jenkinson 2003	√	?	?	√	?	X	?	√	D
Jones a,b 2000	√	?	?	X	?	X	?	√	D
Leigh Brown 1997	√	?	?	√	?	√	?	√	B
McColl a,b 2003	√	?	√	√	X	√	√	√	A
Parkes 2000	√	?	?	√	?	√	?	√	B
Salim Silva 2002	√	?	?	X	?	√	√	√	B
Sutherland 1996	√	?	√	√	?	X	?	√	B
Tai 1997	√	?	√	X	?	√	?	√	B
Ward 1996	√	?	?	X	?	X	?	√	D

ISSN: 1471-2288