Consideration of ICD-9 code-derived disease-specific safety indicators in CKD.

BACKGROUND AND OBJECTIVES: The Agency for Healthcare and Research Quality patient safety indicators track adverse safety events in hospitalized patients but overlook safety incidents specific to CKD. This study considers candidate CKD-pertinent patient safety indicators and compares them with the Agency for Healthcare and Research Quality patient safety indicators. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Using a national Veterans Health Administration database of hospitalized veterans from fiscal year 2005, 247,160 hospitalized veterans with prehospitalization measures of renal function were retrospectively examined for proposed CKD patient safety indicators versus Agency for Healthcare and Research Quality patient safety indicators using International Classification of Diseases, Ninth Revision diagnosis codes. Candidate CKD-pertinent patient safety indicators included in-hospital acute kidney failure; in-hospital congestive heart failure (and related diagnostic codes); electrolyte disturbances; and medication errors, poisoning, and intoxication. Patients with a prehospital estimated GFR<60 ml/min per 1.73 m(2) (CKD group) were compared with a non-CKD group. For CKD patient safety indicators, hospitalizations were excluded if the admitting condition was a potential cause of the secondary condition. Regression methods were used to present adjusted rates in study groups of interest.
RESULTS: The CKD patient safety indicators were generally more common than the Agency for Healthcare and Research Quality patient safety indicators in all groups, tended to occur in different patients than those patients who experienced Agency for Healthcare and Research Quality patient safety indicators, and were more common in the CKD group than the non-CKD group, except for hypoglycemia, hypokalemia, and hyponatremia. The adjusted composite CKD patient safety indicators rate (per 1000 patient-hospitalizations) was 398.0 (95% confidence interval, 391.2 to 405.0) for patients in the CKD group and 250.0 (95% confidence interval, 247.4 to 252.7) for patients in the non-CKD group. The prevalence ratio of CKD patient safety indicators to Agency for Healthcare and Research Quality patient safety indicators was 23.4 (95% confidence interval, 21.9 to 25.0).
CONCLUSION: The candidate CKD patient safety indicators that occur in hospitalized patients are distinct from the Agency for Healthcare and Research Quality patient safety indicators and tend to be more common in CKD than non-CKD patients. These measures have the potential to serve as sentinel tools for identifying patients with CKD who warrant examination for disease-pertinent safety events.