Validation of a claims-based algorithm for identifying non-infectious pneumonitis in patients diagnosed with lung cancer.

PURPOSE: Non-infectious pneumonitis (NIP) is a common complication of treatments for lung cancer. We know of no existing validated algorithm for identifying NIP in claims databases, limiting our ability to understand the morbidity and mortality of this toxicity in real-world data. METHODS: Electronic health records (EHR), cancer registry, and administrative data from a National Cancer Institute-designated comprehensive cancer center were queried for patients diagnosed with lung cancer between 10/01/2015-12/31/2020. Health insurance claims were searched for ICD-10-CM codes that indicate an inpatient or outpatient diagnosis with possible NIP. A 20-code (Algorithm A) and 11-code (Algorithm B) algorithm were tested with and without requiring prescription with corticosteroids. Cases with a diagnosis of possible NIP in the 6 months before their first lung cancer diagnosis were excluded. The algorithms were validated by reviewing the EHR. The positive predictive value (PPV) for each algorithm was computed with 95% confidence intervals (CI). RESULTS: Seventy patients with lung cancer had a diagnosis code compatible with NIP: 36 (51.4%) inpatients and 34 (48.6%) outpatients. The PPV of Algorithm A was 77.1% (95% CI: 65.6-86.3). The PPV of Algorithm B was 86.9% (95% CI: 75.8-94.2). Requiring a documented prescription for a systemic corticosteroid improved the PPV of both Algorithm A and Algorithm B: 92.5% (95% CI: 79.6-98.4) and 100.0% (95% CI: 90.0-100.0), respectively. CONCLUSIONS: This study validated ICD-10-CM and prescription-claims-based definitions of NIP in lung cancer patients. All algorithms have at least reasonable performance. Enriching the algorithm with corticosteroid prescription records results in excellent performance.

High fluoroquinolone MIC is associated with fluoroquinolone treatment failure in urinary tract infections caused by fluoroquinolone susceptible Escherichia coli.

BACKGROUND: Suboptimal clinical response to fluoroquinolone (FQ) therapy has been clearly documented in patients with Salmonella typhi infection with reduced FQ susceptibility. However, the clinical impact of reduced FQ susceptibility on other infections including E. coli urinary tract infections (UTIs) has never been evaluated. METHODS: We conducted a retrospective cohort study of female patients with fluoroquinolone susceptible E. coli (FQSEC) UTIs who received FQ therapy at outpatient services within University of Pennsylvania Health System, Philadelphia. Exposed patients were those with high MIC-FQSEC UTIs (the levofloxacin MIC > 0.12 but ≤ 2 mg/L) while unexposed patients were those with low MIC-FQSEC UTIs (the levofloxacin MIC ≤ 0.12 mg/L). The primary treatment outcome was treatment failure within 10 weeks after initiation of FQ therapy. RESULTS: From May 2008 to April 2011, we enrolled 29 exposed patients and 246 unexposed patients. Two patients in each group experienced treatment failure; exposed vs. unexposed (6.9 vs. 0.8%; p = 0.06). Risk difference and risk ratio (RR) for treatment failure were 0.06 [95% CI -0.03-0.15; exact-p = 0.06] and 8.48 [95% CI 1.24-57.97; exact-p = 0.06], respectively. After adjusting for underlying cerebrovascular disease, the RR was 7.12 (95% CI 1.20-42.10; MH-p = 0.04). CONCLUSION: Our study demonstrated the negative impact of reduced FQ susceptibility on the treatment response to FQ therapy in FQSEC UTIs. This negative impact may be more intensified in other serious infections. Future studies in other clinical situations should be conducted to fill the gap of knowledge.

Empiric potassium supplementation and increased survival in users of loop diuretics.

BACKGROUND: The effectiveness of the clinical strategy of empiric potassium supplementation in reducing the frequency of adverse clinical outcomes in patients receiving loop diuretics is unknown. We sought to examine the association between empiric potassium supplementation and 1) all-cause death and 2) outpatient-originating sudden cardiac death (SD) and ventricular arrhythmia (VA) among new starters of loop diuretics, stratified on initial loop diuretic dose. METHODS: We conducted a one-to-one propensity score-matched cohort study using 1999-2007 US Medicaid claims from five states. Empiric potassium supplementation was defined as a potassium prescription on the day of or the day after the initial loop diuretic prescription. Death, the primary outcome, was ascertained from the Social Security Administration Death Master File; SD/VA, the secondary outcome, from incident, first-listed emergency department or principal inpatient SD/VA discharge diagnoses (positive predictive value = 85%). RESULTS: We identified 654,060 persons who met eligibility criteria and initiated therapy with a loop diuretic, 27% of whom received empiric potassium supplementation (N = 179,436) and 73% of whom did not (N = 474,624). The matched hazard ratio for empiric potassium supplementation was 0.93 (95% confidence interval, 0.89-0.98, p = 0.003) for all-cause death. Stratifying on initial furosemide dose, hazard ratios for empiric potassium supplementation with furosemide < 40 and ≥ 40 milligrams/day were 0.93 (0.86-1.00, p = 0.050) and 0.84 (0.79-0.89, p < 0.0001). The matched hazard ratio for empiric potassium supplementation was 1.02 (0.83-1.24, p = 0.879) for SD/VA. CONCLUSIONS: Empiric potassium supplementation upon initiation of a loop diuretic appears to be associated with improved survival, with a greater apparent benefit seen with higher diuretic dose. If confirmed, these findings support the use of empiric potassium supplementation upon initiation of a loop diuretic.