Table 5. Number of diagnosis-related groups, mean relative weight, and associated standard deviation for each method of computing relative weights, by type of weight.

Type of weight	Number of DRG's1	Mean relative weight	Standard deviation
Operating cost weight	358	1.2186	0.8022
Total charge weight	358	1.2486	0.8745

¹DRG = diagnosis-related group.

NOTES: Data are based on the 358 DRG's for which sufficient information was available on the 1981 Medicare provider analysis review file to compute relative weights. The means reported above are DRG weighted. Relatively low frequency, high-weight DRG's have a greater impact on the DRG weighted mean than on the hospital weighted mean of the case weighted DRG means used in the prospective payment system. As a result, the means reported above are greater than 1.