New York State Department of Health - NYPORTS

Analysis of Procedures Associated with NYPORTS Codes

As part of NYPORTS reporting, hospitals are required to enter the ICD-9-CM procedure code most closely associated with the adverse event. In support of its primary focus-improvement of patient care and safety, NYPORTS continues to accumulate and analyze data reported to the system, including the procedure code. Analysis of procedures associated with reportable cases, however, is difficult due to the large number of individual procedure codes that are reported to NYPORTS. The Agency for Healthcare Research and Quality has developed a tool for clustering patient diagnoses and procedures into a manageable number of clinically meaningful categories. This tool is called Clinical Classifications Software (CCS). This "clinical grouper" makes it easier to understand the types of procedures that are most frequent in the NYPORTS data.

CCS aggregates procedures into 231 mutually exclusive categories, most representing single types of procedures. Some procedures that occur infrequently are grouped together by their clinical or administrative characteristics (for example, operating room vs. nonoperating room). Examples of CCS procedure categories are: heart valve procedures, coronary artery bypass graft (CABG), bone marrow biopsy and procedures on the spleen.

In order for CCS to be used effectively, hospitals must report in NYPORTS the most specific ICD-9-CM procedure code allowable. In 2000, there were 20,095 NYPORTS records that contained an ICD-9-CM procedure code. Of these records, 885 did not match to a CCS group due to the procedure code being invalid. For the year 2001, there were 23,694 records that contained an ICD-9-CM procedure code, of which 372 did not match to a CCS group due to an invalid procedure code.

The next table lists the procedure groups that represent the largest proportion of all NYPORTS cases for the years 2000 and 2001. The distribution of cases into CCS groups for these years was similar and therefore combined. In other words, for adverse events reported to NYPORTS that occurred in 2000 and 2001, the table lists the CCS groups that have the largest number of cases. For example, cases in NYPORTS with the procedure codes partial excision of large intestine, total intra-abdominal colectomy, pull-through submucosal resection of rectum, other pull-through resection of rectum, abdominoperineal resection of rectum, and other resection of rectum, are grouped into the CCS group "colorectal resection". There are 2,003 cases in this group, or 4.8% of the total cases in NYPORTS (2,003/ 42,532 = 4.8).

Procedure Groups Reported Most

Frequently in NYPORTS in 2000/2001

CCS Group 2000/2001 Count % of All NYPORTS Cases in CCS Groups in 2000 and 2001
Colorectal Resection 2,033 4.78
Hysterectomy, abdominal and vaginal 1,547 3.64
Peripheral vascular bypass 1,313 3.09
Hip Replacement, total and partial 1,287 3.03
Cholecystectomy and common duct exploration 1,117 2.63
Treatment, fracture or dislocation of hip and femur 948 2.23
Cesarean section 941 2.21
Other Vascular catheterization, not heart 876 2.06
Arthroplasty knee 789 1.86
Insertion, revision, replacement, or removal of a cardiac pacemaker or cardioverter 748 1.76

An alternative way of using NYPORTS data to describe the frequency of adverse events by procedure involves using both NYPORTS and SPARCS data to describe the percentage of the time that particular procedure groups are reported to NYPORTS. Using this approach, SPARCS data provides an estimate of the total number of procedures that are being performed each year. NYPORTS data are used to estimate the percentage of these procedures that result in a reported event. The following table presents the procedure groups that occur most frequently compared to all cases that are reported in SPARCS. This comparison uses all NYPORTS records within a given group of procedure codes in the numerator and all SPARCS cases with the same group of procedure codes in the denominator. For example, there were 1,698 kidney transplants recorded in SPARCS for 2000 and 2001. Of these cases, 126 (7.4%) involved events which were reported to NYPORTS.

The distribution of cases in the CCS categories in the following table was similar for the years 2000 and 2001, with the notable exception of 'Other organ transplant, not kidney'. For 2000, there were 563 SPARCS records in this CCS category, and 67 of these cases (11.9%) involved events that were reported in NYPORTS. For 2001, there were 654 SPARCS records in this CCS category, and 179 of these cases (27.4%) were reported in NYPORTS. The increase in NYPORTS cases involving events in 2001 was due largely to more liver transplants being reported.

Procedure Groups with the Highest Reporting

Percentage in NYPORTS in 2000/2001

CCS Group Number of Occurrences in NYPORTS for 2000/2001 Number of Occurrences in SPARCS for 2000/2001 Relative Frequency (NYPORTS/ SPARCS)*100
Organ transplantation, not kidney 246 1,217 20.21
Kidney transplant 126 1,698 7.42
Peripheral vascular bypass 1,313 17,381 7.55
Exploratory Laparotomy 424 6,821 6.22
Gastrectomy, partial and total 256 4,180 6.12
Small bowel resection 554 9,840 5.63
Aortic resection, replacement or anastomosis 321 5,778 5.56
Colorectal resection 2,033 41,311 4.92
Incision and excision of CNS 658 15,478 4.25
Embolectomy and endarterectomy of lower limbs 218 5,240 4.16
Insertion, replacement, or removal of extracranial ventricular shunt 234 5,817 4.02

Developing relative frequencies for specific procedures can identify adverse event trends for special interest areas. For example, the following table shows analysis of specific ICD-9-CM codes within the CCS Grouping of Gastrectomy, partial and total. Since this type of surgery has a relatively high complication rate, this grouping provides an opportunity for further analysis to identify trends among specific ICD-9-CM codes.

Procedure Code Occurrences in NYPORTS 2001 Occurrences in SPARCS 2001 Frequency (NYPORTS/ SPARCS)*100
44.31-High Gastric Bypass 70 1281 5.5%
44.39-Other Gastroenterostomy 143 2296 6.2%


213 3577 6.0%