- Thread starter Puriwai
- Start date

This is a simple audit cycle - two groups of 30

27 adults in the Audit 1 group and 29 in Audit 2

When I am reporting the Chi-Square result - the adult result will br N=56, and overall results N=60 as katxt has pointed out ?

Is that correct ? It makes perfect sense

I am, as you no doubt have picked up, very new to biostats

Parameter : Waist circumference

Audit 1. Audit 2

N(%) N(%)

Children 3(100) 1(100)

Adults 11(41) 21(72)

Totals 14(47) 22(73)

Audit 1 has 27 adults and 3 children

Audit 2 has 29 adults and 1 child

Absolute adherence to measuring waist circumference increased in adults by 31%,

chi-square (1,N=56)=6.70,p=.01, and overall by 26%, chi-square(1,N=60)=4.44,p=0.035.

Its the N=56 and N=60 I need to make sure is correct.

You are looking at two separate tests, Adults and Totals. (We will ignore the fact that these two tests use much the same data and so are not independent)

Let's look at the Totals first. We have two audits of 30 total each, a grand total of 60.

14 and 22 adhere, a total of 36.

If there was no difference you would expect 30/60x36 = 18 in each group.

Is a 14 22 split significantly different from a 18 18 split? This is your chi square test. X2 turns out to be 1.78 with a p value of 0.18, so X2(1, N=36) = 1.78, p = 0.18 not sig.

For the adults, 27 and 29 per group 56 total

32 adults adhered so expect 27/56x32 and 29/56x32 = 15.4 and 16.6 for the audits

We actually see 11 and 21. Is this significantly different from 15.4 and 16.6? Chi square test.

This one turns out X2(1, N=32) = 2.45, p = 0.12 not sig.