I am using three variables in my paper. One is barthel index which is scored out of 100. It measures funtional disability of patients.The lower the score the more disabled the patient is.

Second is modified rankin scale which is a global functional disability assessment scale, it is scored out of 6. The higher the score the more severe the disability.

Third variable is the CSI caregiver strain index which measures stress in care givers. Previous studies has shown that caregivers score higher on CSI the lower the barthel index score or the higher the modified rankin scale score is.

Qyestion no1-Now in my study which class of statistical tests should i use, parametric or non parametric?

Question no 2- Of the list of statistical tests available in SPSS , which specific ones will be most useful to study the relationship of barthel index and modified rankin scale with caregiver strain index.

Thank you for your help.