Excess length of stay and readmission following hospital-acquired bacteraemia: a population-based cohort study applying a multi-state model approach.

OBJECTIVES: Population-based estimates of excess length of stay after hospital-acquired bacteraemia (HAB) are few and prone to time-dependent bias. We investigated the excess length of stay and readmission after HAB. METHODS: This population-based cohort study included the North Denmark Region adult population hospitalized for ≥48 hours, from 2006 to 2018. Using a multi-state model with 45 days of follow-up, we estimated adjusted hazard ratios (aHRs) for end of stay and discharge alive. The excess length of stay was defined as the difference in residual length of stay between infected and uninfected patients, estimated using a non-parametric approach with HAB as time-dependent exposure. Confounder effects were estimated using pseudo-value regression. Readmission after HAB was investigated using the Cox regression. RESULTS: We identified 3457 episodes of HAB in 484 291 admissions in 205 962 unique patients. Following HAB, excess length of stay was 6.6 days (95% CI, 6.2-7.1 days) compared with patients at risk. HAB was associated with decreased probability of end of hospital stay (aHR, 0.60; 95% CI, 0.57-0.62) driven by the decreased hazard for discharge alive; the aHRs ranged from 0.30 (95% CI, 0.23-0.40) for bacteraemia stemming from 'heart and vascular' source to 0.72 (95% CI, 0.69-0.82) for the 'urinary tract'. Despite increased post-discharge mortality (aHR, 2.76; 95% CI, 2.38-3.21), HAB was associated with readmission (aHR, 1.42; 95% CI, 1.31-1.53). CONCLUSION: HAB was associated with considerably excess length of hospital stay compared with hospitalized patients without bacteraemia. Among patients discharged alive, HAB was associated with increased readmission rates.

Risk factors for hospital-acquired bacteraemia - an explorative case-control study of hospital interventions.

BACKGROUND: Knowledge on hospital-related interventions as risk factors for hospital-acquired bacteraemia (HAB) is sparse. AIM: We aimed to investigate hospital interventions as risk factors for HAB. METHODS: Prospectively through one year, we identified episodes of HAB in a single tertiary hospital. We used a matched incidence density sampled case-control design. Matching on sex and age group, we sampled controls (1:2) from the adult hospital population with ongoing hospitalization for ≥48 h. Using conditional logistic regression, we estimated odds ratios (OR) with 95% confidence intervals (CI). For adjusted ORs (aOR), adjustments were made for length of hospital stay, type and urgency of admission, and Charlson Comorbidity Index score level. FINDINGS: From 15th October 2019 through 14th October 2020, we identified 115 incident episodes of HAB and matched them with 230 controls. HAB patients were more often admitted as 'medicine or emergency surgery'-patients (94% vs 87%) and had a longer hospital stay before inclusion (median days 20 vs 12). They were more frequently categorized as having a 'low level comorbidity' (58% vs 39%) but had higher prevalence of haematologic (15% vs 6%) or metastatic cancer (13% vs 10%). Our estimates for central venous catheters were aOR of 3.46 (95% CI 1.92-6.23), haemodialysis; aOR 5.05 (95% CI 1.41-18.06), immunosuppressive treatment including chemotherapy; aOR of 1.72 (95% CI 1.00-2.96). CONCLUSION: Central venous catheters and haemodialysis were the most prominent risk factors. Immunosuppressive treatment including therapy may play an important role in the development of HAB.

Incidence and mortality of hospital-acquired bacteraemia: a population-based cohort study applying a multi-state model approach.

OBJECTIVE: The effect of hospital-acquired bacteraemia on mortality is sparsely investigated. We investigated the incidence and hospital-acquired bacteraemia impact on mortality. METHODS: We conducted a 13-year population-based cohort study using the North Denmark Bacteraemia Research Database and Danish health registries. The population comprised all adult patients with a hospital admission lasting ≥48 hr. We used Poisson regression to estimate trends in incidence. The 30-day mortality of hospital-acquired bacteraemia was estimated using an illness-death multistate model with recovery using the population at risk of hospital-acquired bacteraemia as reference. RESULTS: We identified 3588 episodes of hospital-acquired bacteraemia in 484 264 admissions. The incidence increased proportionally by 1.02 episodes yearly (95% CI 1.01-1.03) between 2006 and 2018. Hospital-acquired bacteraemia was associated with increased mortality (adjusted hazard ratio (aHR) 4.32, 95% CI 3.95-4.72), especially hospital-acquired bacteraemia with unknown source (aHR 6.42 (95% CI 5.67-7.26), "thoracic incl. pneumonia" (aHR 5.89, 95% CI 3.45-10.12) and abdominal source (aHR 4.33, 95% CI 3.27-5.74). The relative impact on mortality diminished with age (aHR 5.66, 95% CI 2.00-16.01 in 18-40 years old vs. 3.69, 95% CI 3.14-4.32 in 81-105 years old) and comorbidity (aHR 5.75, 95% CI 4.45-7.42 in low vs. 3.55, 95% CI 3.16-3.98 in high comorbidity), and was higher in elective admissions (aHR 9.09, 95% CI 7.14-11.57 vs. aHR of 4.03, 95% CI 3.67-4.42). DISCUSSION: Hospital-acquired bacteraemia is associated with high mortality, especially when the source is unknown or originating from the thoracic cavity.