A simple calculation can offer a wealth of information. If you want to know how your SNF's Medicare Part A rehab RUGs are stacking up, an easy analysis is at hand. "A SNF can use the rehab RUGs' therapy case-mix index to establish a benchmark for how it compares to other facilities or how the facility compares to itself over time," says Jane Belt, RN, MS, managing consultant for Plante & Moran in Columbus, OH. How it works: Each of the rehab therapy RUG groups has a federal case-mix index for therapy. Thus, all of the ultra highs have a 2.25 case-mix index for therapy, Belt explains. "All of the very highs have a 1.41 and the highs 0.94; mediums 0.77 and lows 0.43" (see the chart on page 34). "The index can give some measurement of the acuity of residents requiring therapy," Belt adds. To see where your facility stands, take the number of resident therapy days per rehab RUG group, multiply that number by the therapy case-mix index for that group, and total those products. Then, divide that total by the total resident therapy days, Belt advises. That will give you the average therapy index for the building. In the example on page 34 where Belt did the calculation, the SNF falls somewhere between very high and high (1.10). "So in that building, on average, therapists generally deliver high rehab" or 325 minutes of therapy, she says. If the figure doesn't match what the SNF is paying its therapy company or what the SNF seems to be providing, that raises some red flags about therapy over utilization -- or perhaps the MDS team isn't capturing the delivered therapy services on the MDS, Belt cautions. Using this approach, Belt says, the SNF can also answer the questions: What is my pattern or trend? Are the trends consistent with the facility's resident population? Does the index compare to the trend in operating costs? Editor's note: Belt presented on the method described in this story and the chart on page 34 at the American Health Care Association's 2007 annual conference.