Predictors of 90-Day Readmissions in Adults With Bacterial Meningitis

Most clinical features and outcomes used to describe meningitis are restricted to the initial presentation, yet ongoing complications of the infection have been shown to be a significant cause of adverse outcomes.1Ellis D.E. Zaoutis T. Thibault D.P. Crispo J.A. Abraham D.S. Willis A.W. Readmissions after hospital care for meningitis in the United States.Am J Infect Control. 2020; 48: 798-804Abstract Full Text Full Text PDF Scopus (1) Google Scholar However, little is known about the risk factors or reasons for readmission in these patients. Therefore, we examined 90-day readmissions of adults hospitalized with a diagnosis of bacterial meningitis using the 2016-2017 Nationwide Readmissions Database. We identified patients admitted for bacterial meningitis and their documented cause using International Classification of Diseases, Tenth Revision (ICD-10) codes. We investigated the rates, reasons, and factors associated with readmission and costs associated with hospitalizations. See the Supplemental Methods (available online at http://www.mayoclinicproceedings.org) for details of our methodology. Of the 12,231 adults we identified who were admitted for bacterial meningitis, 10.7% (n=1309) died during index admission. Of the 10,922 survivors of bacterial meningitis, 28.9% (n=3158) were readmitted within 90 days. Most bacterial meningitis cases had an unknown cause (54.5% [n=5955]), meaning they had an ICD-10 code indicating bacterial meningitis but the pathogen was not specified (eg, G00.9, Bacterial meningitis, unspecified). The characteristics of our cohort, stratified by readmission status, are described in Supplemental Table 1 (available online at http://www.mayoclinicproceedings.org). On multivariable logistic regression, patients with staphylococcal meningitis (adjusted odds ratio, 1.88) and an unknown cause of their meningitis (adjusted odds ratio, 1.30) were significantly more likely to be readmitted in 90 days, as were patients with renal disease, metastatic cancer, and anemia (Table). Of the 3158 patients who were readmitted, nearly 1 in 5 patients were readmitted for sepsis (n=362 [11%]) or meningitis (n=252 [8%]; Supplemental Table 2, available online at http://www.mayoclinicproceedings.org). Of the causes of bacterial meningitis, staphylococcal sp was on average the costliest ($64,026) and Haemophilus influenzae the least costly ($26,307; Supplemental Table 3, available online at http://www.mayoclinicproceedings.org).TableMultivariable Logistic Regression of 90-Day ReadmissionsaOR95% CIP valueAge, per 10 years of age0.960.91-1.01.150Sex MaleReference—— Female1.151.01-1.31.030Household income quartile 1st (lowest income)Reference—— 2nd0.910.77-1.07.240 3rd0.940.79-1.11.463 4th (highest income)0.870.73-1.04.125Payer Private insuranceReference—— Medicare1.040.86-1.26.653 Medicaid0.980.81-1.18.804 Self-pay0.710.50-1.01.060 Other0.940.68-1.29.695Index disposition Routine to homeReference—— Against medical advice2.031.25-3.31.004 Home health care1.361.14-1.62<.001 Transfer other (eg, SNF, ICF)1.671.39-2.00<.001 Transfer to short-term hospital2.611.88-3.63<.001Infectious cause Streptococcus pneumoniaeReference—— Haemophilus influenzae0.850.56-1.31.472 Listeria monocytogenes0.990.63-1.56.967 Neisseria meningitidis0.680.41-1.14.142 Staphylococcal species1.881.45-2.44<.001 Streptococcal species1.100.83-1.45.524 Unknown1.301.06-1.59.013Cardiovascular comorbidities Congestive heart failure1.100.90-1.34.339 Cardiac arrhythmias1.150.97-1.35.101 Valvular disease1.080.83-1.41.553 Pulmonary hypertension1.130.84-1.52.406 Peripheral vascular disorders1.220.91-1.64.185 Hypertension1.110.87-1.41.397Hematologic and oncologic comorbidities Metastatic cancer1.461.04-2.05.029 Solid tumor w/o metastasis1.360.98-1.87.064 Coagulopathy1.180.99-1.42.071 Deficiency anemias1.541.19-2.01.001 Renal comorbidities Renal failure1.371.12-1.69.002 Fluid and electrolyte disorders0.990.86-1.14.864Other comorbidities Diabetes with complications1.050.87-1.28.593 Rheumatic disease1.240.90-1.72.194 Other neurologic disorders0.950.83-1.08.424 Obesity0.820.68-0.99.037 Weight loss1.110.92-1.34.274Procedures Ventricular shunt1.150.82-1.60.413 Invasive CNS procedure1.100.88-1.37.397 Tracheostomy1.020.72-1.45.916 Gastrostomy1.210.90-1.63.216 Hemodialysis1.561.02-2.37.03aOR, adjusted odds ratio; CNS, central nervous system; ICF, intermediate care facility; SNF, skilled nursing facility; w/o, without.Boldface P values represent statistical significance. Open table in a new tab aOR, adjusted odds ratio; CNS, central nervous system; ICF, intermediate care facility; SNF, skilled nursing facility; w/o, without. Boldface P values represent statistical significance. Our estimate of readmissions associated with meningitis (28.9% readmitted within 90 days) is substantially higher than prior estimates, potentially because we limited our investigation to bacterial meningitis. To our knowledge, only 2 other studies1Ellis D.E. Zaoutis T. Thibault D.P. Crispo J.A. Abraham D.S. Willis A.W. Readmissions after hospital care for meningitis in the United States.Am J Infect Control. 2020; 48: 798-804Abstract Full Text Full Text PDF Scopus (1) Google Scholar,2Hasbun R. Rosenthal N. Balada-Llasat J.M. et al.Epidemiology of meningitis and encephalitis in the United States, 2011-2014.Clin Infect Dis. 2017; 65: 359-363Crossref PubMed Scopus (104) Google Scholar have examined readmission after hospitalization for meningitis, neither of which examined risk factors or costs associated with readmission for bacterial meningitis specifically. The pathogen with the strongest association with readmission (and highest cost) was Staphylococcus species. Although readmissions for staphylococcal meningitis have not been previously described, this finding is similar to prior investigations of severe Staphylococcus infections.3Inagaki K. Lucar J. Blackshear C. Hobbs C.V. Methicillin-susceptible and methicillin-resistant Staphylococcus aureus bacteremia: nationwide estimates of 30-day readmission, in-hospital mortality, length of stay, and cost in the United States.Clinical Infect Dis. 2019; 69: 2112-2118PubMed Google Scholar Although staphylococcal sp had the greatest proportional rate of readmissions of different causes, it was only a small portion of the entire cohort (10.6%) and contributes only a modest increase to the overall number of readmissions. More than half of patients had an unknown cause of their bacterial meningitis; these patients were more likely to be readmitted (compared with patients with known causes, aside from Staphylococcus species). Unfortunately, the Nationwide Readmissions Database lacks laboratory values, microbiologic data, imaging, or medications administered (eg, antimicrobials, corticosteroids), so it remains unclear why these patients were at high risk of readmission, and further investigation is warranted. Rodrigo Hasbun has received research support and personal fees from BioFire. Download .pdf (.21 MB) Help with pdf files Supplementary materials