Factors associated with death amongst hospitalised patients with influenza-associated severe acute respiratory illness at four sentinel surveillance sites, South Africa, 2009–2013.

OR—Odds ratio, CI—confidence interval, HIV—human immunodeficiency virus.a Odds ratios and p values shown for all variables included in the multivariable model. For the multivariable analysis of factors associated with death we did not evaluate or include variables which may be on the continuum to the outcome (ICU admission or receipt of mechanical ventilation or oxygen therapy) in the multivariable model.b Asthma, other chronic lung disease, chronic heart disease (valvular heart disease, coronary artery disease, or heart failure excluding hypertension), liver disease (cirrhosis or liver failure), renal disease (nephrotic syndrome, chronic renal failure), diabetes mellitis, immunocompromising conditions excluding HIV infection (organ transplant, immunosuppressive therapy, immunoglobulin deficiency, malignancy), neurological disease (cerebrovascular accident, spinal cord injury, seizures, neuromuscular conditions) or pregnancy. Comorbidities were considered absent in cases for which the medical records stated that the patient had no underlying medical condition or when there was no direct reference to that condition.c Receiving tuberculosis treatment or started on tuberculosis treatment during the course of the admission.d Not evaluated in the multivariable model.e Four additional cases of S. pneumoniae on blood culture not included.f Co-infection with at least one of parainfluenza virus 1, 2 and 3; respiratory syncytial virus; enterovirus; human metapneumovirus; adenovirus; rhinovirus in addition to influenza.g Children Factors associated with death amongst hospitalised patients with influenza-associated severe acute respiratory illness at four sentinel surveillance sites, South Africa, 2009–2013.