Clinical Decision Support for In-Hospital AKI
Work By: Mohammed Al-Jaghbeer,1 Dilhari Dealmeida,2 Andrew Bilderback,3 Richard Ambrosino,4,5 and John A. Kellum1
1 Center for Critical Care Nephrology, Clinical Research Investigation and Systems Modeling of Acute illness Center, Department of Critical Care Medicine,
2 Department of Health Information Management, and
4 Department of Biomedical Informatics, University of Pittsburgh, Pittsburgh, Pennsylvania; and
3 Wolff Center and
5 eRecord Department, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania
ABSTRACT AKI carries a significant mortality and morbidity risk. Use of a clinical decision support system (CDSS) might improve outcomes. We conducted a multicenter, sequential period analysis of 528,108 patients without ESRD before admission, from October of 2012 to September of 2015, to determine whether use of a CDSS reduces hospital length of stay and in-hospital mortality for patients with AKI. We compared patients treated 12 months before (181,696) and 24 months after (346,412) implementation of the CDSS. Coprimary outcomes were hospital mortality and length of stay adjusted by demographics and comorbidities. AKI was diagnosed in 64,512 patients (12.2%). Crude mortality rate fell from 10.2% before to 9.4% after CDSS implementation (odds ratio, 0.91; 95% confidence interval [95% CI], 0.86 to 0.96; P=0.001) for patients with AKI but did not change in patients without AKI (from 1.5% to 1.4%). Mean hospital duration decreased from 9.3 to 9.0 days (P,0.001) for patients with AKI, with no change for patients without AKI. In multivariate mixed-effects models, the adjusted odds ratio (95% CI) was 0.76 (0.70 to 0.83) for mortality and 0.66 (0.61 to 0.72) for dialysis (P,0.001). Change in adjusted hospital length of stay was also significant (incidence rate ratio, 0.91; 95% CI, 0.89 to 0.92), decreasing from 7.2 to 6.0 days for patients with AKI. Results were robust to sensitivity analyses and were sustained for the duration of follow-up. Hence, implementation of a CDSS for AKI resulted in a small but sustained decrease in hospital mortality, dialysis use, and length of stay.
Significance Statement Clinical decision support systems (CDSS) are being implemented in electronic health records to improve detection of AKI, but it is uncertain whether these systems improve outcomes. In a multicenter, sequential period analysis of 528,108 patients, we found that aCDSS resulted in small but sustained decreases in hospital mortality (0.8% absolute decrease), length of stay (0.3 days), and dialysis rates (2.7% absolute decrease) for patients with AKI without affecting outcomes for patients without AKI. Given that AKI occurs in 12% of hospitalized patients or 2.2 million/yr in the United States, these results would, if reproducible, translate into saving .17,000 lives or .$1.2 billion annually.
RESULTS During the 12 months before the implementation of the CDSS, 181,696 patients were admitted across the 14 hospitals in the health care system. In the 24 months after CDSS implementation, 346,412 patients were admitted for a total of 528,108 patients form October of 2012 to September of 2015. The cohorts were compatible in demographic characteristics and comorbidities. The mean6SD age was 59620 years, 57% of the cohort were women, and 84% were white. Baseline characteristics and comorbid conditions for patients in the preCDSS and post-CDSS cohorts are presented in Table 1. AKI was diagnosed by treating physicians in 64,512 patients (12.2%): 20,035 (11%) pre-CDSS and 44,477 (12.8%) postCDSS. Crude mortality was 10.2% for patients with AKI and 1.5% for patients without AKI in the pre-CDSS period. Mortality decreased to 9.4% for patients with AKI (odds ratio [OR], 0.91; 95% confidence interval [95% CI], 0.86 to 0.96; P=0.001), whereas no change was observed in patients without AKI (1.4%) (Figure 2). Similarly, mean hospital duration decreased by 0.3 days (9.3 to 9.0 days; P,0.001)for patients with AKIwhereas, for patients without AKI, mean duration was 5.3 days during both periods (Table 1). In multivariate models including age, sex, race, and comorbidities (Charlson Index), as well as interactions between AKI diagnosis and CDSS status, the adjusted OR for mortality was 0.76 (95% CI, 0.70 to 0.83) using a mixed-effects model (P,0.001). Adjusted hospital LOS was also significant (incidence rate ratio [IRR], 0.91; 95% CI, 0.89 to 0.92), decreasing about 1.2 days for patients with AKI (Table 2). Our resultswere robust to sensitivity analyses. The effects on mortality were greater in medical compared with surgical patients with AKI: adjusted OR for mortality was 0.56 (95% CI, 0.48 to 0.66) for medical patients versus 0.72 (95% CI, 0.54 to 0.95) for surgical patients (Supplemental Table 1). However, results in both groups remained significant (P,0.001 and P=0.02, respectively). Results of our analysis, performed by leaving individual centers out one at a time, are shown in Supplemental Table 2. The point estimate for the adjusted OR for mortality remained quite stable between 0.74 and 0.79. The upper limit of the 95% CI never exceeded 0.87 and all iterations remained highly significant (P,0.001). Similar results were seen for hospital LOS. Adjusted IRR was 0.90–0.92 and the upper limit of the 95% CI was never .0.93; all iterations remained highly significant (P,0.001). As shown in Figure 2, the effects on crude mortality in patients with AKI were sustained for the duration of our analysis. The effect of CDSS on hospital LOS was stronger in surgical patients (IRR, 0.77; 95% CI, 0.74 to 0.81; P,0.001) compared with medical patients (IRR, 0.95; 95% CI, 0.93 to 0.98; P,0.001), with P=0.02 for the interaction. However, no differences were seen for CDSS by age or Charlson. Conversely, the effect of CDSS on mortality was strongly affected by age (P,0.01) such that patients aged 60 years or greater benefitted (OR, 0.75; 95% CI, 0.68 to 0.82; P,0.001), whereas patients aged ,60 years did not (OR, 0.87; 95% CI, 0.75 to 1.04; P=0.13). The effect of mortality was not different by Charlson or by medical versus surgical admissions The distribution of AKI, AKI treated with dialysis, and CKD are shown. Despite an increase in AKI rates from 11% to 12.8%, and CKD rates from 5.0% to 5.7%, dialysis for AKI decreased from 6.7% of patients with AKI to 4.0% (P,0.001). We further analyzed the use of dialysis for AKI using a mixed-effects model. The adjusted OR for dialysis was 0.66 (95% CI, 0.61 to 0.72), for post-CDSS compared with pre-CDSS (P,0.001). The mean number of days patients received common nephrotoxic medications, before and after CDSS, with and without AKI, are shown in Table 4. Days of angiotensin-converting enzyme inhibitor exposure dropped slightly in the cohort overall (1.34 days per patient to 1.25; P,0.001) but the only significant differences in patients with AKI were a decrease in the use of intravascular radio contrast agents (a 45% reduction; P,0.001) and an increase in days of nonsteroidal any inflammatory drug exposure (by 2%; P,0.01). Subspecialty consults actually decreased after CDSS implementation. Nephrology consults deceased for patients with AKI from 30.5% pre-CDSS to 26.9% post-CDSS (P=0.001). Similarly, there was a decrease in critical care consults for these patients from 1.5% to 0.8% (P,0.001).