Osteoarthritis of the Knee Is a Degenerative Disease Causing Joint

Essay

Osteoarthritis of the knee is a degenerative disease causing joint pain, stiffness, anddecreased function. Usual treatment is a combination of physical therapy,medication, and arthroscopic surgery. The arthroscopic surgery involves removal ofcartilage fragments and calcium crystals, or the smoothing of bones to eliminatedifficulties with joint motion. Arthroscopic surgery is widely used, but it is not clearhow, or even if it works. In a recent study patients were randomly assigned to twotreatment groups. Patients in the arthroscopic surgery group received standardarthroscopic treatment plus physical therapy and medicine. Patients in the othergroup received only physical therapy and medicine. Two years after treatment thepatients were evaluated using standard scales for pain, stiffness, and physicalfunction. Higher scores indicate increased pain, increased stiffness, and decreasedphysical function. Pain score data from the study are summarized below. Graphicaldisplays of the data indicate that it is reasonable to assume that the two pain scoredistributions are approximately normal.
(a) What null hypothesis and alternative hypothesis might be used in this setting tocompare mean pain rating for the two treatments?
(b) For your hypotheses in part (a), what is the associated P-Value?
(c) Given your results in parts (a) and (b), what would you conclude about thedifference between the two treatments?
Be sure to give your answer in the contextof this study.