Hi Everyone! I am conducting a retrospective research study to determine if a new specific sign of an injury is correlated with more related injuries to the region than two other signs.

Patients have been sorted into one of three groups (one independent variable):

There are five types of injury that we have measured in each patient (five dependent variables):

In SPSS, I ran a one-way ANOVA with a Bonferroni post-hoc. This seems to give me what I want: 10 P-values for the null hypotheses that Group 2 has the same number of [Injury X] as [Group 1/3].

I have two questions:

1. I used a dummy variable for Injury 5, assigned 0 if the injury is absent, 1 if the injury is present. I recall a professor teaching me that this was acceptable, but I'm having doubts because I can't find examples on the Internet. Is this acceptable? What are the implications if it is?

2. My statistics are a little rusty, so I've been doing a lot of reading and was reminded that, before I chose my post-hoc test, I should have checked that my error variances were equal. A Levene's test gave the following significances:

Patients have been sorted into one of three groups (one independent variable):

- Group 1: Cluster of signs that DOES NOT include the sign of interest (N=22)
- Group 2: Cluster of signs that DOES include the sign of interest (N=19)
- Group 3: Another cluster of signs that DOES NOT include the sign of interest (N=50)

There are five types of injury that we have measured in each patient (five dependent variables):

- Injury 1-Injury 4 are counts of the number of that injury in a patient. e.g. Patient 39 has 5 ligament tears, 2 fractures, etc.
- Injury 5 is whether or not there was any injury to a particular anatomical structure.

In SPSS, I ran a one-way ANOVA with a Bonferroni post-hoc. This seems to give me what I want: 10 P-values for the null hypotheses that Group 2 has the same number of [Injury X] as [Group 1/3].

I have two questions:

1. I used a dummy variable for Injury 5, assigned 0 if the injury is absent, 1 if the injury is present. I recall a professor teaching me that this was acceptable, but I'm having doubts because I can't find examples on the Internet. Is this acceptable? What are the implications if it is?

2. My statistics are a little rusty, so I've been doing a lot of reading and was reminded that, before I chose my post-hoc test, I should have checked that my error variances were equal. A Levene's test gave the following significances:

Injury 1: 0.810

Injury 2: 0.000

Injury 3: 0.386

Injury 4: 0.174

Injury 5: 0.002

So, it appears that my error variances are not equal. From what I've read, I would have been better off with a Dunnett T3 post-hoc. Do you agree with that and would it be responsible to switch at this point?Injury 2: 0.000

Injury 3: 0.386

Injury 4: 0.174

Injury 5: 0.002

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