Recalculation of the Table 2 by Safdar et al.
Source:    Publish Time: 2012-08-23 06:59   1368 Views   Size:  16px  14px  12px
I conducted these analyses were for: Sinclair A, Xie X, Dendukuri N. The Use of Lactobacillus probiotics in the Preven

Author: Xuanqian Xie

#: All cells add 0.5 in calculation. Exact p-values and confidence limits cannot be computed when there are non-integer frequencies.

 

/*Reproduce results of Safdar et al. (2008) study. */

data aa;

input outcomes $ group $ response $ count;

cards;

AAD Florajen Yes 4

AAD Florajen No 19

AAD Placebo  Yes 6

AAD Placebo  No 10

CDAD Florajen Yes 0

CDAD Florajen No 3

CDAD Placebo  Yes 1

CDAD Placebo  No 3

;

 

proc freq data=aa (where= (outcomes="AAD" )) order=data;

      weight Count;

      tables group*Response / chisq relrisk;

      exact FISHER chisq pchi or;

run;

 

 

proc freq data=aa (where= (outcomes="CDAD" )) order=data;

      weight Count;

      tables group*Response / chisq relrisk;

        exact FISHER ;

run;

 

 

 

data aa1;

set aa (where= (outcomes="CDAD" ));

count=count+0.5;

run;

 

proc freq data=aa1  order=data;

      weight Count;

      tables group*Response / chisq relrisk;

      exact FISHER chisq pchi or;

run;

 


 

                                      Fisher's Exact Test

                                ƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒ

                                Cell (1,1) Frequency (F)         3

                                Left-sided Pr <= F          0.1066

                                Right-sided Pr >= F         0.9721

 

                                Table Probability (P)       0.0786

                                Two-sided Pr <= P           0.2072

 

                               ƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒ

                               Odds Ratio                   0.3434

 

                               Exact Conf Limits

                               95% Lower Conf Limit         0.0557

                               95% Upper Conf Limit         1.5553

 

                                         Sample Size = 79

 

/*Reproduce results of Gotz et al. (1979) study. */

data bb;

input outcomes $ group $ response $ count;

cards;

AAD LA Yes 3

AAD LA No 33

AAD Placebo  Yes 9

AAD Placebo  No 34

;

 

proc freq data=bb order=data;

      weight Count;

      tables group*Response / chisq relrisk;

      exact FISHER chisq pchi or;

run;



Safdar N, Barigala R, Said A, McKinley L. Feasibility and tolerability of probiotics for prevention of antibiotic-associated diarrhoea in hospitalized US military veterans. J Clin Pharm Ther 2008;33(6):663-668.

Gotz V, Romankiewicz JA, Moss J, Murray HW. Prophylaxis against ampicillin-associated diarrhea with a lactobacillus preparation. Am J Hosp Pharm 1979; 36(6):754-757.