Methods that include the time-varying nature of healthcare-associated infections (HAIs) avoid biases when estimating increased risk of death and excess length of stay. We determined the excess mortality risk and length of stay associated with HAIs among inpatients in Singapore using a multistate model that accommodates the timing of key events.

Analysis of existing prospective cohort study data.

Seven public acute-care hospitals in Singapore.

Inpatients reviewed in a HAI point-prevalence survey (PPS) conducted between June 2015 and February 2016.

We modeled each patient’s admission over time using 4 states: susceptible with no HAI, infected, died, and discharged alive. We estimated the excess mortality risk and length of stay associated with HAIs, with adjustment for the baseline characteristics between the groups for mortality risk.

We included 4,428 patients, of whom 469 had ≥1 HAI. Using a multistate model, the expected excess length of stay due to any HAI was 1.68 days (95% confidence interval [CI], 1.15–2.21 days). Surgical site infections were associated with the longest excess length of stay of 4.68 days (95% CI, 2.60–6.76 days). After adjusting for baseline differences, HAIs were associated with increased hazards of in-hospital mortality (adjusted hazard ratio [aHR], 1.32; 95% CI, 1.09–1.65) and decreased hazards in being discharged (aHR, 0.75; 95% CI, 0.67–0.84).

HAIs are associated with increased length of hospital stay and mortality in hospitalized patients. Avoiding nosocomial infections can improve patient outcomes and free valuable bed days.

Prevalence of multidrug-resistant (MDR) gram-negative (GN) bacteria is increasing globally and is complicated by patient movement between acute and long-term care facilities (LTCFs). In Asia, the contribution of LTCFs as a source of MDR GN infections is poorly described. We aimed to define the association between residence in LTCFs and MDR GN bloodstream infections (BSIs).

Secondary analysis of data from an observational cohort.

Two tertiary referral hospitals in Singapore, including the 1,400-bed Tan Tock Seng Hospital and the 1,600-bed Singapore General Hospital.

Adult patients with healthcare-onset (HCO) or hospital-onset (HO) GN BSI.

Patients were identified from hospital databases using standard definitions. Risk factors for both MDR GN HCO and HO BSI were analyzed using a multivariable logistic regression model.

A total of 675 episodes of GN BSI occurred over a 31-month period. Residence in a LTCF was an independent risk factor for developing MDR GN BSI (odds ratio [OR], 5.1 [95% confidence interval (CI), 2.2–11.9]; P < .01) when antibiotics were not used within the preceding 30 days. This risk persisted beyond the first 48 hours of hospitalization (OR, 3.4 [95% CI, 1.3–9.0]; P = .01). Previous culture growing an MDR organism (OR, 1.8 [95% CI, 1.3–2.7]; P < .01), previous antibiotic use (OR, 1.8 [95% CI, 1.2–2.6]; P < .01), and intensive care unit stay (OR, 2.2 [95% CI, 1.2–3.9]; P = .01), increased the risk of MDR GN BSI.

Residence in a LTCF is an independent risk factor for MDR GN BSI. Attempts to contain MDR GN bacteria in large Asian cities, where the proportion of the population that is elderly is projected to increase, should include infection prevention strategies that engage LTCFs.

To assess the frequency of community-acquired methicillin-resistant Staphylococcus aureus (MRSA) infections.

A teaching hospital in Singapore.

Prospectively collected surveillance data were reviewed during a 1-year period to determine the extent and origin of community-acquired MRSA infections.

Whereas 32% of 383 MRSA infections were detected less than 48 hours after hospital admission and would, by convention, be classified as “community acquired,” all but one of these were among patients who had been exposed to outpatient centers including dialysis or chemotherapy clinics, visiting nurses, community hospitals, or all three.

With health care increasingly being delivered in an outpatient setting, community-acquired MRSA infections are often acquired in hospital-related sites and most may be more accurately described as “healthcare acquired.” Infection control measures need to move beyond the traditional paradigm of acute care hospitals to effectively control the spread of resistant pathogens.

To determine the additional direct costs of hospitalization attributable to catheter-associated urinary tract infection (CAUTI) in 1,497 newly catheterized patients.

Prospective observational and laboratory study.

University hospital.

Data were collected on risk factors for CAUTI (defined as > 103 colony-forming units [CFU]/mL), severity of illness, and diagnostic and therapeutic interventions in consenting newly catheterized patients. Daily urine cultures were obtained from each newly catheterized patient, but the results of these cultures were not revealed to his or her physician. During the study, one of the investigators (DGM) reviewed each patient's record and made a judgment as to which of the diagnostic tests and treatments ordered and what incremental length of stay could reasonably be ascribed to his or her CAUTI. The total hospital costs for each patient were also obtained.

Overall, 235 patients acquired CAUTIs during the study; most of the CAUTIs were completely asymptomatic, and only 52% were diagnosed by the patients' physicians using the hospital laboratory. Only 1 patient with a CAUTI had a secondary bloodstream infection. Thirty-three (13%) of the CAUTIs were caused by Escherichia coli; 63 (25%) by Klebsiella, Enterobacter, Citrobacter, Pseudomonas aeruginosa, or other antibiotic-resistant, gram-negative bacilli; 87 (35%) by enterococci or staphylococci; and 67 (27%) by Candida species. The 123 CAUTIs diagnosed by the hospital laboratory were judged to have been responsible for an additional $20,662 in extra costs of diagnostic tests and $35,872 in extra medication costs, a mean of $589 (median, $356) per CAUTI. CAUTIs caused by E. coli cost considerably less than infections caused by other gram-negative bacilli ($363.3 ± $228.2 vs $690.4 ± $783.7; P = .02) or yeasts ($821.2 ± $2,169.9). There were less striking differences in the costs per CAUTI caused by staphylococci or enterococci ($387.1 ± $434.8).

The extra direct costs associated with nosocomial CAUTI found in this prospective study, which was done in the era of managed care during the late 1990s, are substantially lower than those reported in the largest comparable studies done more than 15 years ago, most of which were retrospective, reflecting the powerful impact of cost-containment measures that are now implemented in managed care.