Frequencies for mdcdesc variable in drg1991 dataset :

        Major Diagnostic Category (MDC) |
                            Description |      Freq.     Percent        Cum.
----------------------------------------+-----------------------------------
0: PRINCIPAL DX CAN NOT BE ASSIGNED T.. |          9        1.84        1.84
10: ENDOCRINE, NUTRITIONAL & METABOLI.. |         17        3.47        5.31
11: DISEASES & DISORDERS OF THE KIDNE.. |         32        6.53       11.84
12: DISEASES & DISORDERS OF THE MALE .. |         19        3.88       15.71
13: DISEASES & DISORDERS OF THE FEMAL.. |         17        3.47       19.18
14: PREGNANCY, CHILDBIRTH & THE PUERP.. |         15        3.06       22.24
15: NEWBORNS & OTHER NEONATES WITH CO.. |          7        1.43       23.67
16: DISEASES & DISORDERS OF BLOOD, BL.. |          8        1.63       25.31
17: MYELOPROLIFERATIVE DISEASES & DIS.. |         16        3.27       28.57
18: INFECTIOUS & PARASITIC DISEASES, .. |          9        1.84       30.41
        19: MENTAL DISEASES & DISORDERS |          9        1.84       32.24
1: DISEASES & DISORDERS OF THE NERVOU.. |         35        7.14       39.39
20: ALCOHOL/DRUG USE & ALCOHOL/DRUG I.. |          6        1.22       40.61
21: INJURIES, POISONINGS & TOXIC EFFE.. |         17        3.47       44.08
                              22: BURNS |          6        1.22       45.31
23: FACTORS INFLUENCING HLTH STAT & O.. |          7        1.43       46.73
        24: MULTIPLE SIGNIFICANT TRAUMA |          4        0.82       47.55
25: HUMAN IMMUNODEFICIENCY VIRUS INFE.. |          3        0.61       48.16
     2: DISEASES & DISORDERS OF THE EYE |         13        2.65       50.82
3: DISEASES & DISORDERS OF THE EAR, N.. |         31        6.33       57.14
4: DISEASES & DISORDERS OF THE RESPIR.. |         30        6.12       63.27
5: DISEASES & DISORDERS OF THE CIRCUL.. |         45        9.18       72.45
6: DISEASES & DISORDERS OF THE DIGEST.. |         40        8.16       80.61
7: DISEASES & DISORDERS OF THE HEPATO.. |         18        3.67       84.29
8: DISEASES & DISORDERS OF THE MUSCUL.. |         49       10.00       94.29
9: DISEASES & DISORDERS OF THE SKIN, .. |         28        5.71      100.00
----------------------------------------+-----------------------------------
                                  Total |        490      100.00

by Jean Roth , jroth@nber.org , 22 Apr 2016