study	treatment	diff	std.err
1    	A       	NA  	0.5035062
1    	C       	-0.31  	0.668089651
2    	A       	NA  	0.2821224
2    	B       	-1.7  	0.382640605
3    	C       	NA  	0.2651650
3    	D       	-0.35  	0.441941738
4    	C       	NA  	0.3354102
4    	D       	0.55  	0.555114559
5    	D       	NA  	0.1973566
5    	E       	-0.3  	0.274276316
6    	D       	NA  	0.1998441
6    	E       	-0.3  	0.320087245
7    	A       	NA  	0.5047146
7    	B       	-2.3  	0.71774604
7    	D       	-0.9  	0.694988091
