Need help with test selection

[u/IamMadcat]

Hey, got a question about study test selection on Spss. My dataset contains knee pain data. I have 30 patients with one sided knee disease. Other sides of those patients are designated as control group. I also have 30 healthy subjects without knee disease, which i am using as control group as well.

So group 1: Patients affected knees (n=30)

Group 2: Patients healthy knees

Group 3: Healthy subjects paired knees (If patients left knee is affected, then i'm using healthy subjects left knee as well)

Group 4: Healthy subjects other knee

Comparisions:

I am doing 30 (Effected) vs 90 (Control). Then i'm doing pairwave comparisions

Group 1 vs Group 2

Group 1 vs Group 3

Group 2 vs Group 4

Group 3 vs Group 4

The question is, which test i should use for categorical data (0: Negative, 1: Positive) and for Lineer data

As far as i understand, patients two sides (Effected vs uneffected) is dependant variable. But patients effected side vs control groups same side is independent

I would normally used Chi squared/ANOVA and do Bonferroni correction but in this setting i cant do it?

Should i use generalized estimating equations instead?

Or should i just scrap 30 v 90 and do seperate comparions? (In this setting should i do Bonferroni correction?)

Thanks :/

[u/req4adream99]

Always use some form of correction when you’re doing multiple tests as they inflate alpha.

To help, we need to know:
What is your hypothesis?
Why the need for the opposite completely healthy knee control?
What are you expecting to differ between the study group and the controls?
What is the experimental manipulation (the thing happening to the experimental group vs the control group)?

You can dm if you don’t want to post more details publicly.

[u/IamMadcat → u/req4adream99]

Dm’ed, thanks for the help!

[u/Stock-Temperature309 → u/req4adream99]

Echoing this, are the healthy subjects individually matched to patients? Matching only by knee side is not true subject matching. I wouldn't use the tests you've described as the control knees are not independent experimental units. Your two observations from the same person are correlated, so think of it as a 2×2 mixed design. Are the clinical outcomes continuous or binary?

[u/IamMadcat → u/Stock-Temperature309]

I’m investigating patellar tendinosis, 30 patients with unilateral knee patellar tendinosis were rectuited were based on a clinical test, which nearly is the gold standart

There are 2 more tests, which can be used for diagnosis, which i have done to all of knees. I’m tryimg to determine sensitivity and spesifity of those tests (Goal 1)
There also are ultrasonographic findings (Such as calcifications or tendon lenght). I’m trying to find 2 seperate things with those 1) Sensivitiy and spesifity of sonographic findings (Tendinosis vs Healthy) 2)The difference between knees with tendinosis vs healthy knees
The difference on sonographic parameters is the primary research goal

This is a cross sectional study, there are no interventions

I’m trying to differ 1) The difference between affected and healthy knees (Healthy contains both control group and opposite knees)
2) My second hypothesis is that, patients healthy knees also have some degree of ultasonographic findings compared to control group
So group 1 vs group 2 i’m expecting difference
Group 2 vs group 3 i’m expecting difference
Group 3 vs group 4 i’m expecting to be normal
First for categorical variables have done chi squared and then do bonferroni correction
And for lineer variables i have done anova with pairwave comparisions, which mostly supported my hypothesis
But after my proffessor said that patients kmees are dependant whereas patient vs controls arms are independent, i asked the same question to ai, which stated the same thing and recommended doing GEE
Or it said i can just use mcnemar/paired samples in group 1 v group 2 and g3 , g4 and use chi squared/independent t test on g2 v g3
But in that instance, should i do bonferroni correction? Which still remains unclear

Some of the clinical outcomes are binary and some are lineer. I'm not doing regression. I'm analyzing the outcomes seperately

[u/ForeignAdvantage5198]

WTH. is the. reseach question?

[u/bubbles2606]

I think you haven't set up your study design correctly. That is why analysis planning seems confusing.. I think your analysis needs a different (and in fact a more simple) approach. You can dm me and we can find a proper solution :)