Older adults often have atypical presentation of illness and are particularly vulnerable to influenza and its sequelae, making the validity of influenza case definitions particularly relevant. We sought to assess the performance of influenza-like illness (ILI) and severe acute respiratory illness (SARI) criteria in hospitalized older adults.

Prospective cohort study.

The Serious Outcomes Surveillance Network of the Canadian Immunization Research Network undertakes active surveillance for influenza among hospitalized adults.

Data were pooled from 3 influenza seasons: 2011/12, 2012/13, and 2013/14. The ILI and SARI criteria were defined clinically, and influenza was laboratory confirmed. Frailty was measured using a validated frailty index.

Of 11,379 adult inpatients (7,254 aged ≥65 years), 4,942 (2,948 aged ≥65 years) had laboratory-confirmed influenza. Their median age was 72 years (interquartile range [IQR], 58–82) and 52.6% were women. The sensitivity of ILI criteria was 51.1% (95% confidence interval [CI], 49.6–52.6) for younger adults versus 44.6% (95% CI, 43.6–45.8) for older adults. SARI criteria were met by 64.1% (95% CI, 62.7–65.6) of younger adults versus 57.1% (95% CI, 55.9–58.2) of older adults with laboratory-confirmed influenza. Patients with influenza who were prefrail or frail were less likely to meet ILI and SARI case definitions.

A substantial proportion of older adults, particularly those who are frail, are missed by standard ILI and SARI case definitions. Surveillance using these case definitions is biased toward identifying younger cases, and does not capture the true burden of influenza. Because of the substantial fraction of cases missed, surveillance definitions should not be used to guide diagnosis and clinical management of influenza.

Surgical site infections (SSIs) following colorectal surgery (CRS) are among the most common healthcare-associated infections (HAIs). Reduction in colorectal SSI rates is an important goal for surgical quality improvement.

To examine rates of SSI in patients with and without cancer and to identify potential predictors of SSI risk following CRS

American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) data files for 2011–2013 from a sample of 12 National Comprehensive Cancer Network (NCCN) member institutions were combined. Pooled SSI rates for colorectal procedures were calculated and risk was evaluated. The independent importance of potential risk factors was assessed using logistic regression.

Multicenter study

Of 22 invited NCCN centers, 11 participated (50%). Colorectal procedures were selected by principal procedure current procedural technology (CPT) code. Cancer was defined by International Classification of Disease, Ninth Revision, Clinical Modification (ICD-9-CM) codes.

The primary outcome of interest was 30-day SSI rate.

A total of 652 SSIs (11.06%) were reported among 5,893 CRSs. Risk of SSI was similar for patients with and without cancer. Among CRS patients with underlying cancer, disseminated cancer (SSI rate, 17.5%; odds ratio [OR], 1.66; 95% confidence interval [CI], 1.23–2.26; P=.001), ASA score ≥3 (OR, 1.41; 95% CI, 1.09–1.83; P=.001), chronic obstructive pulmonary disease (COPD; OR, 1.6; 95% CI, 1.06–2.53; P=.02), and longer duration of procedure were associated with development of SSI.

Patients with disseminated cancer are at a higher risk for developing SSI. ASA score >3, COPD, and longer duration of surgery predict SSI risk. Disseminated cancer should be further evaluated by the Centers for Disease Control and Prevention (CDC) in generating risk-adjusted outcomes.

Infect Control Hosp Epidemiol 2018;39:555–562