Hello.

  To compare means, you should use Independent sample t-test (for 2 groups) and ANOVA (three or more groups). In this case the WOMAC score will be the independent variable, and the groups are independent variables.

  However for the use of parametric tests (t-test and ANOVA), must ensure that conditions exist for its use (WOMAC Score should have a normal distribution in the studied sample and .... etc (any practical book of SPSS, it has a very simple way.) If the WOMAC not have a normal distribution, you can always use non-parametric tests (Mann-Whitney-Wilcoxon for two-sample test or Kruskal-Wallis test for three or more samples). Any practical book of SPSS, is a  good guide.

see this link:https://www.rheumatology.org/Practice/Clinical/Clinicianresearchers/Outcomes_Instrumentation/Western_Ontario_and_McMaster_Universities_Osteoarthritis_Index_(WOMAC)/

has information on how to score the WOMAC

  Good luck.

Hi, 

You can use ANOVA, if there is more than two groups. To find out difference between groups  you can select any post hoc test also.

WOMAC score is a continuos variable, so you can discard the chi square. If the scores are normally distributed, you can use the t-test (2 groups) or ANOVA (more than 2 groups). If the scores are not normally distributed, you can use non-parametric tests. You can find plenty of books on the subject here http://gen.lib.rus.ec/

thank you all, suggestions were very helpful for conducting my analysis.