Table 3.

Direct comparisons between different types of hormone replacement therapy (HRT). Values are adjusted odds ratios (95% confidence intervals)

HRT comparison	QResearch	CPRD	Combined analysis	P
Oral v transdermal	1.74 (1.57 to 1.93)	1.61 (1.39 to 1.87)	1.70 (1.56 to 1.85)	<0.001
E2 only v CEE only	0.87 (0.76 to 1.00)	0.81 (0.66 to 0.98)	0.85 (0.76 to 0.95)	0.005
E2 combined v CEE combined	0.85 (0.76 to 0.94)	0.81 (0.69 to 0.94)	0.83 (0.76 to 0.91)	<0.001
CEE norgestrel v CEE MPA	0.72 (0.61 to 0.85)	1.07 (0.85 to 1.35)	0.87 (0.59 to 1.29)	0.5
E2 MPA v CEE MPA	0.70 (0.50 to 1.00)	0.64 (0.39 to 1.07)	0.68 (0.51 to 0.91)	0.01
E2 dydrogesterone v CEE MPA	0.54 (0.42 to 0.69)	0.61 (0.42 to 0.88)	0.56 (0.45 to 0.69)	<0.001
E2 norethisterone v CEE MPA	0.76 (0.66 to 0.87)	0.88 (0.72 to 1.08)	0.80 (0.71 to 0.89)	<0.001
E2 other v CEE MPA	0.60 (0.39 to 0.93)	0.88 (0.44 to 1.76)	0.67 (0.47 to 0.97)	0.03

CEE=conjugated equine oestrogen; CPRD=Clinical Practice Research Datalink; E2=estradiol; MPA=medroxyprogesterone acetate.