Evaluating the Impact of a New Model of Care Designed to Improve Evidence-based Management of Community-acquired Pneumonia

Each year community acquired pneumonia (CAP) causes 61,000 hospital admissions (2006-7 data) and incurs costs of more than AUD300 million in Australia. At the investigators' institution, over 1000 admissions per year have an average hospital length of stay (LOS) of 5 days and incur average clinical costs of AUD6,724 per admission (2012/13 data). Prolonged LOS not only has significant implications for organizational costs but is also strongly associated with adverse patient outcomes including loss of function due to de-conditioning and higher incidence of hospital-acquired adverse events including hospital-acquired infections, intravascular-device associated complications and antibiotic-related side effects. Reducing LOS therefore benefits both the patient and the health system. General Internal Medical (GIM) services manage the largest proportion of CAP patients at Western Health, with 47% of CAP admissions managed by GIM in 2012/13 (average age 75 with proportions with at least 1, 2 or 3 active co-morbidities 70%, 43% and 27% respectively). With population ageing, the elderly and highly multi-morbid population treated by GIM units will constitute the bulk of Australia's future health service burden for CAP.

A number of interventions for improving clinical outcomes in CAP are now supported by recently accrued level 1 evidence. Following a Cochrane review in 2011 that suggested adjunct corticosteroids accelerate time to clinical stability, a number of trials have since demonstrated favorable outcomes. Most notable are two landmark large randomized controlled trials (RCT); a study of the effect of corticosteroid on reducing treatment failure in severe CAP published in JAMA, and a study published in the Lancet in 2015 that demonstrated faster clinical recovery and shorter LOS (by 1 day) without significant adverse events.10 A subsequent meta-analysis (2000 patients from 12 RCTs) confirmed these findings and routine adjunctive corticosteroid is now widely supported though as yet not consistently deployed. Early mobilization safely and effectively reduces LOS when applied appropriately as does early switch to oral antibiotics guided by a set of well-defined basic clinical and laboratory criteria. Recently, a RCT incorporating both measures demonstrated a LOS reduction of 2 days compared to standard care. A meta-analysis of nutritional support in malnourished medical inpatients (a patient cohort that includes those admitted with CAP) showed that systematic screening for risk of malnutrition and targeted nutritional therapy intervention reduces non-elective readmission rates.

No existing study has assessed bundling all four established interventions (corticosteroid, early switch to oral antibiotics, early mobilization and systematic screening for malnutrition and targeted nutritional therapy). However, adherence to consensus guidelines for CAP is notoriously poor suggesting the major challenge will be in bridging the "evidence-practice gap" and particularly changing clinician behavior. Generalist clinicians are becoming increasingly overwhelmed by a plethora of guidelines for multiple illnesses that may co-exist in the same patient. Currently at Western Health, 43% of CAP patients receive corticosteroids, 63% physiotherapy (median time to initiation 2 days) and 65% a guideline-compliant antibiotic. No parenteral antibiotic stopping rules are in place (median 3 days). There is a current compliance rate of 72% for malnutrition risk screening in inpatients across the health service. The investigators believe therefore, that in order to address this gap between evidence and practice, an alternative service model is necessary to ensure best practice specifically for this leading contributor to health service burden.

The investigators propose evaluating a stand-alone over-arching "syndrome-based" clinical service for CAP analogous to those already applied in other areas (e.g. "stroke-services" credited with substantial improvements in outcomes from acute cerebrovascular disease). The proposed "CAP Service" would have core responsibility for ensuring comprehensive and rigorous current evidence-based best practice by application of a standardized set of management algorithms incorporating interventions supported by Level 1 evidence.

Service evaluation will take the form of a stepped wedge study design, a type of cluster RCT that is particularly well-suited to implementation and health services research. Importantly, the investigators have already successfully implemented this design in health services research at Western Health. The primary research question is to quantify the impact of a dedicated CAP Service delivering consistent and standardized evidence-based care on length of stay, costs, 30- and 90-day readmission rates and mortality.