The following is a summary of “Peritoneal Dialysis–Associated Peritonitis Trends Using Medicare Claims Data, 2013-2017,” published in the February 2023 issue of the Kidney Diseases by Young et al.

Peritonitis caused by peritoneal dialysis (PD) is a severe problem that prevents it from being widely used to treat people with renal failure. Studies of large clinical populations could improve understanding of peritonitis. To better describe peritonitis trends and identify its clinical risk factors, researchers used Medicare claims data to quantify peritonitis rates. Data on claims, eligibility, modality, and demographics were extracted from standard analytic files in the US Renal Data System. Medicare fee-for-service (FFS) patients who submitted claims for dialysis or hospital care and were reimbursed during the study’s time period (from 2013 to 2017) were included in the sample. Age, gender, race/ethnicity, year of renal replacement therapy, kidney failure reason, and history of peritonitis all played a role in determining the likelihood of developing the infection. Peritonitis was the most common result, and it was diagnosed using both ICD-9 and ICD-10 codes. Multiple reports of peritonitis within a 30-day period were considered to be the same episode.

From a total of 396,289 claims for peritonitis, researchers were able to isolate 70,271 cases. There was no one universally accepted code for documenting a case of peritonitis. Multiple claims were frequently used to identify cases of peritonitis; in fact, the average number of claims associated with an episode was 5.6, and the median number was 2. About 4 in 10 cases occurred in the outpatient setting, 9% occurred in the hospital, and 16% were recorded using codes that do not differentiate between peritonitis and inflammation or infection of a catheter (“catheter codes”). A total of 0.54 peritonitis were reported per episode patient-year (EPPY). When only episodes with claims from nephrologists or dialysis providers were considered, the incidence dropped to 0.35 EPPY from 0.45 EPPY when including catheter codes. Patient characteristics such as age (lower rates at higher ages), race (Black > White > Asian), and history of peritonitis (greater rate with each prior episode) all contributed to the overall 5% annual drop in the peritonitis rate. Their presence shows a need for uniformity in the use of codes. Catheter codes alone may lead to false positives in terms of episodes. There was no verification of peritonitis cases using symptoms or microbiological information. The incidence of peritonitis caused by PD decreases with age, and elderly individuals experience it less frequently. A claims-based methodology can benefit the investigation of peritonitis caused by PD.

Source: sciencedirect.com/science/article/pii/S0272638622008630