We found substantial variation in hospital-level processes of care, empiric antibiotic selection, LOS, and 14-day readmission in this multicenter study of children hospitalized with CAP. Increased utilization of diagnostic testing was associated with a longer hospital LOS. Hospital-level differences in LOS correlated inversely with 14-day post-discharge ED visit but despite this there was no association with readmissions. Our findings highlight the need for strategies to identify the most efficient processes of care for children with CAP and to determine when children with CAP are sufficiently stable for hospital discharge.
The processes of care evaluated in this study varied widely by institution, raising questions about the utility of some of these tests. Although we did not apply a measure of severity for pneumonia in these children such as the pneumonia severity index used in adults,19
we did attempt to study a relatively uniform population by including only children admitted directly, rather than by inter-hospital transfer, to an inpatient ward (rather than an intensive care unit), who received antibiotics but no pleural drainage procedures and who lacked underlying chronic comorbid conditions. While the inverse correlation between LOS and 14-day re-visit to the ED is concerning for incompletely resolved illness it certainly does not support a lesser degree of illness for patients with shorter LOS. Additionally, the absence of a difference in the rate of 14-day readmission would favor small rather than large differences in illness severity. Despite this relative homogeneity, certain processes of care (e.g, CRP) were never or almost never used at some institutions while at other hospitals they were employed in nearly all patients, even when the median use of the test by institutions was almost zero (i.e., fewer than 10% of patients). Thus, large differences in patient population do not appear to account for variation in testing.
Substantial variability also occurred in antibiotic preference in this cohort both by institution and by age group. Furthermore, the majority of children received broad spectrum antibiotic therapy although this cohort consisted of patients with uncomplicated, non-severe CAP. This wide variability in antibiotic preference highlights the lack of clear national standards for the management of CAP in children. For adults admitted with CAP, the American Thoracic Society and the Infectious Diseases Society of America guidelines provide principles for empiric antibiotic therapy.20,21
In a study of adults with CAP, adherence to the American Thoracic Society/Infectious Diseases Society of America antibiotic therapy recommendations was associated with improved outcomes compared with non-adherence.22
The recently published guidelines for children with CAP will hopefully improve standardization of diagnosis and treatment.23
Increased use of some processes of care was associated with a longer LOS. The effect on LOS may have been magnified by several hospitals at the two extremes of care utilization that also had large differences in LOS. While evident at the institutional level which were ranked according to the total number of laboratory tests, the effect of increased utilization may not hold true for any individual child with CAP or even any individual test. The American Thoracic Society/Infectious Diseases Society of America guidelines for hospitalized adults with CAP recommend chest radiographs, complete blood count, blood cultures, electrolytes and oxygenation assessment. Some diagnostic processes such as complete blood counts and acute phase reactants (ESR, CRP) have poor sensitivity and specificity in the diagnosis of bacterial pneumonia in children.24–27
Furthermore, children who present to EDs have a low rate of bacteremia, and falsely positive blood cultures may contribute to unnecessary prolonged stay and antibiotic use.28
Although the correlation of increased utilization of processes of care with longer LOS occurred in this population, the precise interaction of processes of care with study outcomes remains unclear. The observed association between use of processes of care and LOS has two plausible explanations. First, patients at institutions with greater use of processes of care were indeed sicker and thus the diagnostic testing helped to establish the severity of their illness. We cannot exclude this possibility but the wide variation in each individual test by institution in a fairly homogenous population makes differences in illness severity an unlikely explanation. Second, increased testing may have occurred as a condition of variation in institutional practice patterns. In this case, certain processes of care may beget further testing, additional interventions, increased costs and a longer LOS. Previous studies in children have established diverse practices in other acute illnesses in children which have resulted in varied costs and outcomes.2–7
This study had several limitations. First, we applied only one approach to measuring and ranking utilization of processes of care. In so doing, we may have forced rankings on hospitals though there may not have been substantial variation in the performance of specific tests. Second, we considered that children with more severe disease would likely have a longer LOS, rendering the comparison of processes of care among children with less severe disease complicated. Thus, by design, our study was restricted to a relatively homogenous group of patients without evidence of severe or complicated disease such as the presence of an underlying chronic comorbid condition or admission to the ICU, receipt of antibiotics or a pleural drainage procedure on the first hospital day. Despite these efforts, we cannot completely rule out residual confounding by disease severity which is an inherent limitation of our data source and the lack of standardized severity scale for children with CAP. We were unable to evaluate the rate of post-discharge physician visit in this population. However, the fact that children from institutions with shorter length of stay also had higher rates of 14-day ED re-visit may be explained in many ways such as incomplete resolution of symptoms or inadequate education of family members on discharge. Yet the higher rate of 14-day ED visits does not support less severe illness in children with shorter LOS and lower rates of diagnostic testing. Third, our assessment of care processes was limited to diagnostic testing. Other hospital-level factors may influence hospital LOS. For example, it is possible that physicians across hospitals used comparable criteria to make discharge decisions but that hospitals varied in the efficiency with which they could discharge patients, leading us to falsely identify an association between higher diagnostic test utilization and a longer LOS. Fourth, variability in outpatient care which we could not measure may have affected readmission rates. Fifth, if children were readmitted to a hospital that did not contribute to PHIS we could not track those readmissions. Finally, while we identified an association between increased utilization of diagnostic testing and longer hospital LOS, we could not determine which specific tests or whether any specific tests ought to be performed less frequently.
In conclusion, we demonstrated wide variation in hospital-level processes of care, antibiotic therapy and outcomes in this study of children hospitalized with non-severe CAP. The absence of established guidelines during the study years may have contributed to this wide variability in testing, suggesting an important target for influencing both the efficiency and quality of pediatric health care. Guidelines of care that promote certain laboratory studies may need to be evaluated in light of these findings. Reducing practice variability is an important step in improving quality of care while reducing costs, and the recent publication of diagnostic and management guidelines for childhood CAP, jointly sponsored by the Pediatric Infectious Diseases Society and the Infectious Diseases Society of America,23
may contribute to reduce variability in the care of children with pneumonia.